Talk:Solid-state drive

Article merged: See old talk-page here

Merging Flash drive into Solid-state drive

The following discussion is closed. Please do not modify it. Subsequent comments should be made in a new section. A summary of the conclusions reached follows.

The result was merge into Solid-state drive. -- Zodon (talk) 04:46, 10 September 2008 (UTC)

---

NOTE: The proposal is to merge the article Flash drive into Solid-state drive, the proposed merge has nothing to do with the USB flash drive article. (This clarification added part way through the discussion Zodon (talk) 18:53, 18 August 2008 (UTC)).

I agree that the merge seems like a good idea. Zodon (talk) 21:25, 25 June 2008 (UTC)

I concur. --Laser brain (talk) 21:26, 25 June 2008 (UTC)

Disagree: All flash drives are solid state drives, but not all solid state drives are flash drives. They're still different things and should be kept seperate. Lightblade (talk) 23:29, 27 June 2008 (UTC)

Yah but flash could be its own topic under SSD, and still have its differences noted. JMAN1156

Flash drives are already covered in the solid-state drive article, it is not clear that they have enough unique features to warrant a separate article. It isn't necessary to have an article about every subtype of an item. Please explain why they should be separated out from the other solid-state drives. Thanks. Zodon (talk) 00:30, 2 July 2008 (UTC)

Disagree: Flash drives imply portability and "hot swappable" type behaviour, like a USB pen, whereas talking about solid state drives implies usage as permanent hard disks - I think this means that they are 2 seperate things. Merging these would be like merging CD's and Floppy Disks, because they are both types of disk... —Preceding unsigned comment added by 62.255.249.197 (talk) 08:48, 8 July 2008 (UTC)

Acutally SSD are hot swappable, if you use raid and sata hot swappable drives teh SSD can be used instead of traditonal hard disks.Andrewcrawford (talk) 20:23, 17 August 2008 (UTC)

Please observe that the article in question for merging is Flash drive, not USB Flash drive. The Flash drive article even states "Unlike USB flash drives and memory cards, flash drives tend to physically imitate conventional hard drives in size, shape, and interface so that they may act as a replacement for hard drives." The article about flash drive makes none of the distinctions you mention for flash drives. (There is no reason a SSD can't be hot swappable, using an external enclosure, E-SATA, etc.)

There are so many little articles about similar devices that it makes sense to combine a few of them. Since flash drive is a subset of SSD, and the article overlaps a lot with this one, it makes sense to merge them. The see also section of the Flash drive article has a reasonable summary of a few of the different related types. The flash drive entry should probably become a disambiguation page (pointing to USB flash drive, or SSD, etc.). Zodon (talk) 01:22, 9 July 2008 (UTC)

I agree with Zodon. The "Flash Drive" article is confusing: The common use of the term "Flash Drive" implies "USB." Merging "Flash Drive" with this article and creating a disambiguation page for "Flash Drive" is an excellent idea. Horseadmonition (talk) 16:56, 5 August 2008 (UTC)

Strongly Agree Do not see any difference for USB / other bus drives. They all need software support (driver) to operate. Also there are conventional USB HDDs at hand. The article must be more sructured and there should be separate parts for RAM/"standard" flash/USB flash drives (else we'll have to distinguish IDE/SATA/SAS/InfiniBand/other buses SSDsStasdm (talk) 17:07, 17 August 2008 (UTC)

Strongly Agree There are already USB RAID (RAID 0 actually, but it's only the beginning). Once again - do we describe technology or use/application and bus differences? Most flash SSDs (exept for newest ones)are IDE - any native RAID for them? And EDE/SATA SSDs are quite often used to transfer data - especially in publishing industry, where seem to be a standard already. Stasdm (talk) 12:46, 18 August 2008 (UTC)

One why give your agurement twice? and second there is no IDE ssd that i know of mostly because the interface can not handle it correctly. USB can not be used as raid, it can be used to elimated raid on linux but that quite hard to do. windows can not handle it nor do it. RAID also requires teh drives are fixed ;) which last time i checked usb flash drive arentAndrewcrawford (talk) 13:47, 18 August 2008 (UTC)

Please clarify how your argument against relates to the articles in question. The article on Flash drive says. "Unlike USB flash drives and memory cards, flash drives tend to physically imitate conventional hard drives in size, shape, and interface so that they may act as a replacement for hard drives." So both flash drive and SSD are primarily disk replacements.

What does whether USB drives can be used in RAID or not have to do with the merger proposal? Neither article proposed for merger deals with USB to any great extent. (Whether it is a discussion of features of USB drives, or evolving into a proposal to merge the USB flash drive article, please either relate it back to the topic of this discussion, or start another thread for it.)

Since several of the people commenting in this thread seem to have been confused about what articles are proposed for merger, I added a note at the top with links to which hopefully will help keep the discussion on track. Zodon (talk) 18:28, 18 August 2008 (UTC)

I am merely asking why the previous person isung saying ot merge it on the fact of USB flash pens. This what was there arguemnt to merge for so i am quesiton it.Andrewcrawford (talk) 18:45, 18 August 2008 (UTC)

Strongly AgreeOk after reviewing the the article in question rather than go on what is here, i say the articel should be merged here as it basically describing SSD.Andrewcrawford (talk) 19:43, 18 August 2008 (UTC) previous comment removed

Agree. It doesn't matter whether the two terms are identical - it is their overlap that matters, and they to appear to have a very large overlap. GregorB (talk) 13:03, 9 September 2008 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

i-RAM

I DO thing the i-RAM insertion is a kind of SPAM! Somone is triing to sell off the now obsolete product. If my note on tha i-RAM obsolete state will be deleted one more time, I surely will have to delete the whole paragraph!Stasdm (talk) 07:17, 13 October 2008 (UTC)

RAM-based SSD's become obsolete

Let's consider. 1. Read speed of both RAM and "RAIDed" flash drives might be as fast as the interface allows (at least two vendors are now ready to supply SATA 3 flash SSD with 500-600 MB/sec read speed. 2. Write speed is a bit more difficult to manage, but Micron already samples flash SSD with 250 MB/sec write speed, May also rise the write speed to 400-500 MB/sec with some price tag added (interleaving needs a bit more complex approach. 3. In principle, it is now possible to produce direct PCIe (even direct to memory channel - see Intel Turbo Memory) attached flash subsystems with multiple levels of interleaving and stripping working on PCIe 3 speed with the price no greater than $20 per GB.

The "wear-out" issue is also becoming less significant - mothern drives may work up to 3-5 years as Vista OS drives.

Compare this price with prices on cheapest RAM-based solutions and you'll see that (might be exept for very rare ultra-write-intensive SQL applications) flash SSDs are now much more price/performance attractive than RAM-based (with the same functionality).Stasdm (talk) 07:04, 13 October 2008 (UTC)

This isn't my field, but

...this story on Engadget today (http://www.engadget.com/2008/07/01/ocz-reveals-core-series-sata-ii-2-5-ssds-128gb-for-479/) looks pretty significant: "these drives check in at $169 (32GB), $259 (64GB) and $479 (128GB), which -- as you undoubtedly recognize -- are amazing price points. Each unit utilizes NAND flash technology, possesses a 1.5-million hour mean time before failure and delivers 120 - 143Mbps read / 80 - 93Mbps write speeds. The sub-0.35ms seek times are also worthy of a tip of the hat, and the low power consumption just makes things unnecessarily sweeter." - Dan Dank55 (talk)(mistakes) 20:29, 1 July 2008 (UTC)

Answer: Unfortunately, all this data is not quite right and needs to be looked at with a lot of care. The mtbf does not have any meaning at all, it could as well last 10 minutes. Also consider that those drives use MLC and not SLC chips. The random write is much worse than the stated 80 Mbps (which means Mbit per second and is wrong in this case. It should be MB/s = Megabyte per second). Alltogether: The prices are dropping, herewith the quality. —Preceding unsigned comment added by RunningGer (talk • contribs) 12:12, 3 August 2008 (UTC)

Subject matter/WP:V, WP:OR, WP:RS experts needed re. ATA/ATAPI support for SSD

Greetings. I am currently having great difficulty with editor Ramu50 re the Advanced Technology Attachment article, specifically over whether solid state drives are "really" supported by ATA.

They are by SATA by not by PATA, if the user want to prove otherwise fineAndrewcrawford (talk) 20:25, 17 August 2008 (UTC)

No, the PATA spec includes specific provisions for SSD. Anyway this is long since settled. Jeh (talk) 18:05, 5 September 2008 (UTC)

I claim they are; the ATA docs say so, explicitly and also by inclusion ("any form of storage device may be placed on the interface"). Ramu50 claims that citing the ATA docs is "original research". Accordingly Ramu50 has repeatedly removed the mention of SSDs from the article lede.

I have opened a case at WP:RSN. The specific section at WP:RSN is here. I've included a large number of diffs there.

This dispute is also discussed, if that is the word, in a long thread (actually several) at the AT Attachment article's talk page: talk:Advanced Technology Attachment.

The input of any SSD or ATA subject matter experts and/or Verifiability, Original Research, or Reliable Sources experts would be appreciated. Thank you. --Jeh (talk) 09:26, 17 July 2008 (UTC)

"faraday cage"

I'm going to let someone else check me on this, but I'm almost 100% sure this statement is completely irrelevant. A faraday cage is basically anything conductive surrounding the drive--there is no reason why SSDs do not have a faraday cage, and I'm almost certain all reasonable manufacturers already use a metal case for their SSDs (they're expensive enough already, why would they skimp with plastic?) Anyway, one problem DRAM-based versions might be susceptible to are soft errors (read on wikipedia). Generally, I'd imagine this is pretty easily mitigated with some error correction (which probably is implemented, anyway. . .) Threepointone31 (talk) 06:06, 7 September 2008 (UTC)

12 GB minimum size for minilaptop?

Several vendors are selling linux based minilaptops with only 4 GB of storage.

For example:

http://www.dell.com/content/products/productdetails.aspx/laptop-inspiron-9

Include a note as the need to do away with windows bloatware (t.m.) in order to accomplish this for a useful device.

Hcobb (talk) 17:00, 7 September 2008 (UTC)

I assume you were commenting about the line where it said that SSDs range from 12GB to 256GB. Since there was no citation for it, and both of those numbers are dubious at best, even if they were correct when written they aren't likely to stay so for very long, so I removed the sentence. Zodon (talk) 19:37, 9 September 2008 (UTC)

Input on SSD article from Storage Networking Industry Assoc. Solid State Storage Initiative

Hello Wiki-editors. Last week, while speaking to an SSD industry analyst, I discovered your SSD article. It's actually quite good. Recently, the Storage Networking Industry Assoc. (SNIA -- www.snia.org) started a new group within our organization called the Solid State Storage Initiative (SSSI). We would like to help edit and contribute to your SSD article and hopefully related content / articles. Is there a particular Wikipedia editor or editorial group we should dialog with?

Thanks.

72.20.136.100 (talk) 18:53, 11 September 2008 (UTC)Neal Ekker

If you are looking for a particular editor your best bet is to you look on the hardware taskforce first then computing project. If you are not fussed majority of editors here will be glad to help you improve the article :)--Andrewcrawford (talk) 19:13, 11 September 2008 (UTC)

Andrew, can we copy the current content, edit it in a Word doc, provide citations as per Wikipedia instructions, and e-mail this doc to you? Then you or another editor could post the content with all the Wikipedia conventions, scripts, etc. so that we wouldn't fumble the ball with those? Or is that too much work on your side and we should just dive into the Edit This Page text and root around as we will? I want to work with Wikipedia in whatever way is best for Wikipedia. Would you be kind enough to give me some guidance?

Neal —Preceding unsigned comment added by 72.20.136.100 (talk) 21:57, 11 September 2008 (UTC)

I have a lot of work on so that would be asking a lot of me, i am willing to help you update it but that just a little to much for me. If you edit each section to what is more appropriate then add reference for it using <ref></ref> i will edit it later to comply more with wikipedia guidance. --Andrewcrawford (talk) 08:12, 12 September 2008 (UTC)

Andrew-

Sorry for taking so long to respond, but Hurricane Ike came through and provided some distraction here in Houston (we were closed for a week), then we had our first Solid State Storage Initiative (SSSI) elections and productive meetings out at IBM in San Jose. Fun. Now I'm back in the saddle. I don't want to cause you more work; I want to help SSSI contribute to your already impressive SSD content. I've discovered that others in the Storage Networking Industry Assoc. (SNIA) have contributed to Wikipedia previously. Let me find out from them if we have an experienced Wikipedia writer, and if so, maybe we can supply all our own contributions with minimal help from you. Neal

No problem i cant take on full project my self jsut now have my degree to do weirdly it covering SSD but only minorly. If you post a edit toa section or add a new section send mea message on my talk page ill check it out and make improvement to wikipedia standard wehre necessary and put work to yourself :) but please do not do the entire page at once i just abut have a heart attack--Andrewcrawford (talk) 22:41, 26 September 2008 (UTC)

Write cycles and wear leveling

Please stop removing cited material. If you think the information is incorrect, please provide citations for other views on the matter.

The Infoworld article Lucas Mearian (August 27, 2008). "Solid-state disk lackluster for laptops, PCs". Retrieved 2008-09-12. says:

"Corporate-grade SSD uses single-level cell (SLC) NAND memory and multiple channels to increase data throughput and wear-leveling software to ensure data is distributed evenly in the drive rather than wearing out one group of cells over another. And, while some consumer-grade SSD is just now beginning to incorporate the latter features."

"It matters whether the SSD drive uses SLC or MLC memory. SLC generally endures up to 100,000 write cycles or writes per cell, while MLC can endure anywhere from 1,000 to 10,000 writes before it begins to fail," [according to Fujitsu's vice president of business development Joel Hagberg.]

Most of the articles on flash media that I have seen here provide no citations to back up statements about wear leveling being used or not used in various devices. The main citation used in several articles for the number of write cycles seems to be a web page documenting a Linux file system, which gives a number with no basis whatever (and it isn't clear to what extent the source is a WP:RS for that information). The infoworld article cited may be mistaken in these matters, but at least it is a citation in an at least moderately reliable source.

If there are other views on the matter - fine, provide some reliable sources and lets fix it up. (i.e., I make no claims for the correctness of the information in the infoworld article, but by Wikipedia standards, it is better than what was there in that it is verifiable) Zodon (talk) 01:18, 21 September 2008 (UTC)

My edit comments was obviously too brief, so I will have to try to be even more explicit: First, as you seem to imply yourself, the "cited" article may not be very reliable, as it uses a quite sloppy and tendensious tone, even in its own quotations. Furthermore, a more complete version of your quotation above would be:

"Consumer-grade SSD generally uses multilevel cell (MLC) NAND flash memory, which has greater capacity and a lower-price point but suffers from slower I/O and as much as 10 times fewer read/writes over its life span. Corporate-grade SSD uses single-level cell (SLC) NAND memory and multiple channels to increase data throughput and wear-leveling software to ensure data is distributed evenly in the drive rather than wearing out one group of cells over another. And, while some consumer-grade SSD is just now beginning to incorporate the latter features to increase its performance, there will still be a cost/capacity disparity for years to come."

Here, "the latter features" probably aims at "SLC" and "multiple channels", not at "wear-leveling" (as it reads "performance"). The fact that wear-leveling is mentioned last is likely due to careless writing/aiming, ignorance, or the tendensious style that characterizes much of the article. Most importantly, it is certainly not anything from which you could deduce a categorical statement like "wear levelling is not common in consumer level devices"... For that, you would need either an explicit citation from a reliable source or concrete examples of "consumer level devices" without wear levelling.

A longer version of your second quotation reads: "For one thing, it matters whether the SSD drive uses SLC or MLC memory. SLC generally endures up to 100,000 write cycles or writes per cell, while MLC can endure anywhere from 1,000 to 10,000 writes before it begins to fail, according to Fujitsu's Hagberg. For its part, Western Digital's laptop hard-disk drive boasts up to 600,000 write cycles." What about the tone and style here?

Another citation clearly illustrates how the writer guesses: "With software enhancements, MLC can exceed SLC performance, but at its core, it's still MLC memory, which means its life span is greatly reduced because cells store more data more often. In fact, generally speaking, the higher performance in an SSD drive, the longer life it will have because of better drive efficiency.". Anyone with a basic understanding of fundamental "flash memory technology" would see that this is quite confused guesswork.

Here are some other articles and papers about wear levelling at various technical levels; I could not find a single one suggesting that "wear levelling is not common in consumer level devices":

http://www.stec-inc.com/technology/flash_memory_controller.php

http://techreport.com/articles.x/15433

http://www.storagesearch.com/ssdmyths-endurance.html

http://lwn.net/Articles/288657/

http://www.cdfreaks.com/news/14976-Experts-warn-about-SSD-security-risks.html

http://www.engadget.com/2008/02/23/samsung-puts-the-kibosh-on-ssd-reliability-worries/2

http://www.mycom.se/product_info.php?products_id=54602

http://www.e-disk.com/article_misconceptions_ssd_longevity.html

http://www.hardwarecanucks.com/forum/storage/8690-ssd-wear-leveling-partitions.html

http://www.solidkor.com/en/technology/414we.html

http://oss.oracle.com/pipermail/btrfs-devel/2008-February/000513.html

http://www.imation.com/products/pdfs/SSD-Reliability-Lifetime-White-Paper.pdf

http://www.imation.com/products/pdfs/Imation-SSD-Performance-White-Paper.pdf

HenkeB (talk) 12:27, 25 September 2008 (UTC)

My comment about the matter of reliability of the source was purely courtesy. The edit summaries trying to remove the source claimed that the information was incorrect (without giving any citations or basis for that claim). It was and is not obvious that the source is biased or incorrect, I was just trying to invite discussion.

Article interpretation:

1. Since wear leveling is the last feature mentioned, it is reasonable to assume it is one of the "later features," however many other features were intended. I don't see trying to re-interpret it to fit some other idea of what it should say.
2. Since consumer level SSDs do exist and have existed for a while, but the statement was made that they are just starting to incorporate these features, that can reasonable be interpreted as the ones existing prior to now didn't. However I have improved the item by making it closer to what the cited source says. (i.e. that they are starting to incorporate this feature now (2008).

It is not clear what point you are trying to make about the tone and style of the quotation relating to number of write cycles. It seems a straight forward presentation of information. The information given seems to correspond to what I have seen elsewhere as far as flash (I thought the figures for hard disks were interesting, but I haven't seen figures to compare them to.)

I didn't make use of the final section quoted, so I don't see what the point is.

I haven't had a chance to look at the citations you provided yet. I will look at them as time permits, or perhaps you have suggestions for improvements to the item which incorporate these sources which we could discuss? Zodon (talk) 07:57, 26 September 2008 (UTC)

If you really was "trying to invite discussion", then please try consider my arguments.

1. It's not about "some other idea", it's about correctness. Your interpretation would seem reasonable giving the short out of context excerption you prefer to look at, however, a slightly longer version makes that interpretation very dubious (see above).
2. You cannot possible use a single source for your categorical conclusion about "consumer level devices" unless the quality of the source is at the level of a neutral and reliable academic paper. Otherwise, you would need either more than one source or concrete examples to support that kind of bold statement (third time I say this...)
3. Given the fact that wear leveling has been used in various cheap devices (CF, SD, USB-sticks etc) for many years (see references in the wear leveling article, for instance), it would be a little naive to belive that SSDs did not.
4. "I didn't make use of the final section quoted, so I don't see what the point is." Really? If you are that uninterested in technical basics, perhaps you should delegate some decisions on precise formulations to other people (with the knowledge needed to judge whether things makes sense or not).

HenkeB (talk) 14:16, 26 September 2008 (UTC)

I responded to your arguments where they related to the article, agreeing that the wording of the wear leveling part could be improved, and asking for clarification about what you found questionable in the section on number of writes. Beyond that, I requested clarification of what is the point of critiquing the source's style, or the clarity of other sections of the article which weren't used in the Wikipedia article.

The wear leveling article was quite thin on references of the sort you mention when I looked a few days ago, as was the USB flash drive article. I looked at various other articles on flash devices, they tended to mention what wear leveling is, but were short on actual citations backing up claims that they were used in this or that type of device, or measurements of quality/etc.

Why make such a big deal about trying to discredit this one reference? It is a news item, so one does not expect the same level of care/writing/understanding as an article in Nature. It improved the wikipedia article by providing some basis for the statements made there. For the purpose of Wikipedia, verifiability is the quality metric, not "correctness," so lets get more that is verifiable. I suggested at the outset that rather than asserting that something is correct without evidence, that evidence be provided to support that view. I still think that that is a more constructive approach.

If wear leveling is commonly used in consumer grade SSDs - fine, what reference says so?

Does the quality of wear leveling vary much? (i.e., is it a marketing buzzword that everybody claims, but some do better than others).

If MLC drives offer more write cycles than mentioned in the article - how many, and what reference says so? etc. Zodon (talk) 22:06, 26 September 2008 (UTC)

First, what exactly do you mean by "Please cease your personal attacks on me at talk:Solid state drive. If you wish to courteously discuss article improvements, fine. Zodon (talk) 21:53, 26 September 2008 (UTC)" on my talk page? I find that quite discomforting.

I'm trying very hard to discuss article improvements, with very little success unfortunately. Once again, my main point is that you cannot rely on a single arbitrary source for your categorical conclusion about "consumer level devices" unless the quality of the source is at the level of an academic paper. Otherwise, you would need something more, such as examples, to support that kind of bold statement.

Yes, verifiability is important, but verifiability does not mean you can take any source, regadless of quality, and (more or less) loosely "interpret" what it says. You need detailed knowledge of your own (sometimes expertise), to be able to judge which sources can be considered reliable and what information relevant and/or reasonable. Truth and correctness must always be number one for any encyclopedia, that's the reason we have them.

HenkeB (talk) 23:45, 26 September 2008 (UTC)

Update: Answers to your questions:

• "If wear leveling is commonly used in consumer grade SSDs - fine, what reference says so?" As I said above, there is no reason to suspect "consumer grade" SSDs should be exceptions from other flash based devices, such as cheap CF, SD, and USB devices, which have employed wear leveling for several years (see external links in the wear leveling article for instance). The reason it's not written out explicitly may be the same as why computer manufacturers seldom explicitly state that this model has heat sink and fan in order to prevent the CPU from self destruct (if you see my point).
• It varies, but not to the extent that the limited number of block erases easily shines trough, not even in fairly extreme cases. The most pessimistic life expectancy calculations I've seen is 5 years (a hypothetical scenario of continous writing at max bandwith 24/7 for five years); more "typical usage" life expectancies can be anywhere between 23 years and thousands of years (see my links above, for instance, or the wiki linked in the SSD article).
• I think most manufacturers specify 10,000 block erase cycles for multi-level NAND-flash, at least that's the figure in datasheets and papers I have come across. Speculating a little, I suspect most SSDs (as opposed to low cost CF/SD/USB devices) will use single level in the future, as the saving is only a factor of two, and multi-level inherently a little slower.

HenkeB (talk) 17:00, 27 September 2008 (UTC)

'Problems with SSDs on Windows'

The linked article for this section doesn't cover the statements, especially:

"Many Windows users who purchase the MLC disks are baffled as to why the performance of their flash drive is slow." "The final problem is that the NTFS file system isn't well suited for these flash disks." "but the fact remains that MLC and SLC disks both perform exceedingly well in Linux using a journaled filesystem like ext3, attaining write speeds far above manufacturer benchmarks, as high as 126MB/s with sequential writes"

I'm tempted to scrub this section altogether unless someone can provide a source or re-write so that the section more accurately represents what the source says. Macthorpe (talk) 06:46, 22 September 2008 (UTC)

I put in some citation needed tags. Although it could use some polishing of the language, and some of the details need citation or deleting, the basics don't seem to be too unlikely to be true, just needs a bit more citation. I have seen other citations on problems with Windows and flash media (e.g. Windows doesn't handle large write blocks of flash efficiently). Suggest leave it for a while and try to accumulate sources. Zodon (talk) 04:50, 23 September 2008 (UTC)

The claims of this section are specious IMO. The claim about 512 byte sectors is wrong, as the Windows file cache does readahead and writebehind in 64KB buffers minimum. I believe the claim about Windows processes constantly accessing the flash drive is misplaced also, as I don't believe the indexing and similar mechanisms normally pay attention to removable drives. Jeh (talk) 11:30, 12 October 2008 (UTC)

Do you have any citations for that? Various people in the industry say the poor performance under Windows is because of differences between hard disks and SSD, and Vista has been optimized for hard disks.

SSD are not usually treated as removable drives, they look to the machine like hard disks. Zodon (talk) 19:47, 12 October 2008 (UTC)

Yes, various people in the SSD industry say that; file under "yes, they would say that, wouldn't they?" The citation for the 64KB readahead/writebehind in the file cache, page reads, and the modified page writer is of course Russinovich and Solomon, Windows Internals. Also note that the default (and very widely used) allocation cluster size on NTFS is 4 KB. Really, I'm very familiar with the Windows I/O system, file systems, etc., and I just don't see where it is "optimized" for a 512 byte sector size. btw the notion of "running with virtual memory turned off" is pretty laughable. Re. removable drives, sorry, I was thinking of add-on drives, not drives mounted as internal. So things like indexing would still be happening, but I see no reason to think these should burden a SSD proportionally more than they burden a hard drive. Jeh (talk) 00:41, 13 October 2008 (UTC)

Not clear why they would say that about Windows, and not about other operating systems. Note that one of the articles also says that Apple and Sun are working on optimizations for flash. The item started out with some more particulars about how some Linux file systems perform better with flash SSD.

As far as references - I meant to ask about references indicating that either Windows didn't have performance issues with flash based drives, or that the issues were likely due to other causes. The size of the readahead/writebehind cache seemed easy enough to document, wasn't questioning that. But where bottle-necks are can be more subtle (e.g. data misalignment, etc.). Sorry my message above wasn't very clear on that.

Seems like the impact of indexing might depend a lot on how much writing it did and in what pattern. Zodon (talk) 04:22, 13 October 2008 (UTC)

Seperating Flash and RAM based SSD Advantages and Disadvantages

Combining them directly like this is confusing at best, which I don't think they should be entirely different sections they could be sub headers such as, however this is just an example.

Advantages
+Shared
+RAM Specific
+Flash Specific

Disadvantages
+Shared
+RAM Specific
+Flash Specific

--70.230.234.166 (talk) 06:39, 25 September 2008 (UTC)

I agree, flash storage and DRAM-based hd-emulators have little in common (only the IDE interface basically). As such, they should really be separate articles, as before.

HenkeB (talk) 12:34, 25 September 2008 (UTC)

Seems like they were only proposing rearranging the advantages/disadvantages sections along these lines (rather than splitting the article). Such a re-arrangement of that section might clarify, it is a little hard to tell without seeing it. Part of what complicates it is that many of the parameters vary by capacity (the curves start out one place, but then they cross because of different slopes). Perhaps such parameters might be better covered outside the advantages/disadvantages format. Zodon (talk) 08:17, 26 September 2008 (UTC)

Removal of timeline

I removed this because it's a massive spam magnet and gives the false impression that SSD's are a very recent invention. Maybe a few of the announcements are notable enough to be put back but it's hard to tell which ones. Towel401 (talk) 11:58, 4 October 2008 (UTC)

Well, the flash drive (like it's cousins CF,SD etc) is in fact a fairly recent invention. A natural split of this article into a Flash-drive and a RAM-drive article (much like before) would solve this problem as well as others, such as the messy advantages/disadvantages section. RAM-drives and flash-drives does not use the same memory technology, neither do they have the same purpose (basically speed boosts in high perfomance computers versus (semi-) permanent storage in harsh environments such as laptops and embedded systems), the only thing in common would be the IDE/SATA interface, not enough to lump them together as I see it. HenkeB (talk) 18:08, 4 October 2008 (UTC)

I think removing the section seems reasonable. How would splitting flash vs. RAM would help this? (Section would still be a big spam magnet.) Zodon (talk) 06:40, 5 October 2008 (UTC)

When were flash-based and RAM-based SSD separate articles? The history is common to both. The two current implementations of SSD have more in common than just the interface. Architecture seems to be similar (interface - controller - storage), and since they both use semiconductor chips, the packaging issues may be similar. Both are touted for performance improvements (at least in high-end versions). The function could be dealt with similarly to the USB flash drive article - storage devices (link to relevant article with summary) plus controller/interface. Not much point in splitting until one of them grows to the point where the article becomes unmanageably large. Zodon (talk) 06:40, 5 October 2008 (UTC)

1. Once, there was a separate flash-drive article, but it was merged into this one (see above).
2. The timeline covered (more or less) the recent history of flash-drives, why remove that? (Being a "spam magnet" is a completely different issue.)
3. "Architecture seems to be similar (interface - controller - storage), and since they both use semiconductor chips,..."; using that kind of logic you could merge hard-disks, CD-RWs, DVDs, and floppy-drives, into a single article as well.
4. "packaging issues may be similar"... ??
5. The only function of a RAM-drive is to boost performance; flash-drives are primarily rugged and low power storage. Yes, the fact that some flash-drives are very fast and/or energi-efficient makes for an overlap in some "high-end" applications (could perhaps replace both hard-disks and RAM-drives in the future). However, they are still fundamentally different (see next point).
6. Yes, linking between articles at various levels of generality/detail is a great thing, but it wouldn't work well as basic categorization is done wrongly. RAM-drives are inherently volatile, flash-drives are not, a fundamental difference.

HenkeB (talk) 18:49, 5 October 2008 (UTC)

The history section already mentions stuff used in the 70's while the timeline started in 2005. It's only recently that they gained popularity but even IDE-based flash modules have been around for ages. I don't think RAM based drives should get their own article just yet - the section currently takes up only a few kb of the 25k this article is now and the GC-RAMDISK already has an article for some strange reason. Maybe that article can be merged into the new RAM drive article if someone decides to make one.Towel401 (talk) 22:30, 5 October 2008 (UTC)

The timeline is not my major concern here (as you probably have grasped), although I find no reason to exclude recent history (when someone has made an effort to include it). The question of age is very much about how far it's reasonable to stretch a definition; one could argue that the first SSDs were core memory (solid state although not transistors) or, at the other extreme, that is was the first commercial product that was named SSD and also resembling a hard-disk, or whatever. However, it's hard to escape the fact that various form of "RAM-drives" and "RAM-disks" has been around much longer than any flash-device, as flash technology was developed in the eighties and grew large (in both popularity and capacity) during the nineties.

Furthermore, I don't think we should be so concerned with the size of articles, that's really secondary, but instead try to concentrate on achieving the most logical and natural structure among (as well as within) articles. In this case, Solid State Drive would better be a rather small "umbrella" article covering some general history and technology and mentioning that the term SSD has come to denote so quite different products (and why). From there RAM-drive and Flash-drive can be linked, which, of course, cover each respective concept/product in detail. (Yes, it would be a good idea to merge GC-RAMDISK into a RAM-drive article :) Regards. HenkeB (talk) 23:45, 5 October 2008 (UTC)

The timeline had devolved into a list of product announcements. There was no clear indication that the items were historically important. The history section might be better place to gather items that are historically significant. May be slightly less prone to spamming.

If by separate flash drive article, you mean the one that was merged per the proposal above, this article still covered both RAM and flash based SSDs. When that article was merged into this one, this article changed very little; as I recall the see-also section was the main content that came from the other, most of the rest was duplication.

There are already quite a number of articles on flash based storage, with a lot of duplication, creating flash drive would be yet another. Articles tend to gather material (many editors just add to whatever article is in front of them without looking at how articles relate).

The different characteristics of DRAM memory vs. Flash mean there are different considerations when building one, but volatility is not necessarily an end-user concern. A DRAM based SSD appears non-volatile to the user. From a users perspective they aren't fundamentally different - you have an interface, something on the other end remembers the data you write at a location and gives it back to you when you ask for it. Whether that something is a hard disk, DRAM, flash, bubble memory, etc. means they have different characteristics (power usage, access time, startup time, etc.) but it is functionally the same.

SSD can be the small umbrella article, without the separate flash-drive and DRAM based drive articles. Zodon (talk) 02:28, 6 October 2008 (UTC)

1. I actually agree on your first point!
2. "If by separate flash drive article, you mean the one that was merged per the proposal above," frankly, please don't pretend...
3. The lead (the by far most important part) was primarily about flash-drives, I rewrote large parts of it myself.
4. Preventing duplication should not be our main concern; duplication is not even necessarily a bad thing, rather a nessesity in many cases, to achive good readability and clarity.
5. Yes, it's true that some RAM-drives achieve a kind of non-volatility with the help of non-volatile hard-drives. But, that specific kind of "end user perspective" is only one among many different possible perspectives, the buyer, the engineer, and the technically interested reader are, among others, well as important. And again, these RAM-drives are completely useless as permanent storage in laptops and similar, thus a completely different kind of product.
6. The last part is an overly abstract picture, to say the least. If that is your only possible point of view, I suppose you would like to merge each and every data storage article on WP into a single one? And, if not, why use hypocritical arguments?
7. "SSD can be the small umbrella article, without the separate flash-drive and DRAM based drive articles." So where do all the specific details go then? Are you against detailed technical information per se?

HenkeB (talk) 06:17, 6 October 2008 (UTC)

Need a 'manufacturers' section

Need a 'manufacturers' section, at least for SATA based SSDs. - xpclient ^Talk 19:20, 11 October 2008 (UTC)

I don't know if that's really a good idea. THere is one on the CompactFlash page and obscure manufacturers keep adding their red links to it. Is there an official policy on this? Towel401 (talk) 20:23, 11 October 2008 (UTC)

Why is such a section needed? As noted, seems likely to become a spam magnet, much as the timeline was. (Wikipedia is not a directory, etc.) Zodon (talk) 06:53, 12 October 2008 (UTC)