Enter the Poorly Designed MLC

The great thing about everyone making MLC drives based on the same design is it helps drive cost down, which gives us a very affordable product. After rebate you can buy a 64GB OCZ Core SSD, an MLC drive, for $240 from Newegg. Compared to the $1000+ that 64GB SSDs were selling for a year ago, this is good cost savings. The bad thing about everyone using the same design however is if there's a problem that affects one of the drives, it affects all of them. And indeed, there is a problem.

The symptoms are pretty obvious: horrible stuttering/pausing/lagging during the use of the drive. The drive still works, it's just that certain accesses can take a long time to complete. It's a lot like using a slow laptop hard drive and trying to multitask, everything just comes to a halt.

I first discovered this problem a couple of months ago when I started work on an article looking at the performance of a SSD in a Mac Pro as a boot/application drive. Super Talent sent me one of its 3.5” drives, which I had assumed was a SLC drive. Application launches were ridiculously fast, but I noticed something very strange when I was using my machine. Starting to type in a document, or sending an IM, or even opening a new tab in Safari would sometimes be accompanied by a second-long pause. At first I assumed it was a problem with my drive or with the controller, or perhaps a combination of the drive, the SATA controller on the Mac Pro’s motherboard and OS X itself. I later found out it was an MLC drive and thus began my investigation.

SuperTalent had received a lot of attention for its SSDs, and rightfully so - they were starting to be affordable. OCZ however quickly took the spotlight with its Core SSD, finally bringing the price of a 64GB MLC SSD to below $300. Users flocked to the Core and other similarly priced drives, because if you looked at the marketed specs of the drive you were basically getting greater than SLC performance, at a fraction of the cost:

Advertised Specs OCZ Core (MLC) OCZ (SLC)
Read Up to 143MB/s Up to 100MB/s
Write Up to 93MB/s Up to 80MB/s
Seek < 0.35ms unlisted
Price < $300 > $600

 

However the real world performance didn't match up.

Let's start with the types of benchmarks that we usually see run in SSD reviews, here's a quick run of PCMark Vantage's HDD. Vantage paints the Core as a screamer:

  PCMark Vantage HDD Test
OCZ Core (JMicron JMF602, MLC) 8117
OCZ (Samsung, SLC) 12143
Western Digital VelociRaptor (10,000 RPM SATA) 6325

 

Digging a bit deeper we only see one indication of a problem, performance in the Media Center test is significantly slower than the VelociRaptor - but overall it's much faster, what could one test actually mean?

  Windows Defender Gaming Picture Import Vista Startup Windows Movie Maker Media Center WMP App Loading
OCZ Core (JMicron JMF602, MLC) 48.1MB/s 72.5MB/s 90.4MB/s 47.9MB/s 23.2MB/s 33MB/s 17.8MB/s 20.3MB/s
OCZ (Samsung, SLC) 69.3MB/s 71.8MB/s 86.9MB/s 63MB/s 43.7MB/s 65.6MB/s 33.8MB/s 39.9MB/s
Western Digital VelociRaptor (10,000 RPM SATA) 27.5MB/s 20.1MB/s 59.0MB/s 22.9MB/s 58.5MB/s 113.3MB/s 15.2MB/s 7.6MB/s

 

If we turn to SYSMark however, the picture quickly changes. The OCZ SLC drive is now 30% faster than the MLC drive, and performance in the Video Creation suite is literally half on the MLC drive. Something is amiss.

  SYSMark 2007 Overall E-Learning Video Creation Productivity 3D
OCZ Core (JMicron JMF602, MLC) 138 143 111 134 168
OCZ (Samsung, SLC) 177 161 200 178 172
Western Digital VelociRaptor (10,000 RPM SATA) 179 155 222 177 169

 

The Generic SSD Delving Deeper
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  • Anand Lal Shimpi - Tuesday, September 09, 2008 - link

    I think the question was: how much more performance is left untapped by current controller designs? The JMicron issues are a limited case, what will truly be telling is what happens when we see Intel vs. Samsung with SLC drives...

    The dominating the charts line was in reference to the Crysis results. If you've ever run the Crysis GPU bench you'll know that it is extremely disk intensive (particularly the first run). As I mentioned in the article, it over emphasizes the importance of disk performance but that's not to say that the results aren't valid.

    I do see your point however, let me see what I can do about clarifying that statement.

    -A
    Reply
  • yyrkoon - Tuesday, September 09, 2008 - link

    Ok, I guess I missed the JMicron 'thing', but to be perfectly honest I dislike *anything* JMicron and try to avoid them whenever possible. I guess I am just so interested in these Intel drives, I just tuned everyting else out. However, I did read what you mentioned about 'trouble-shooting' the JMicron MLC issue.

    Never ran Crysis, and do not plan on running it anytime soon if ever, but I am somewhat of a hardcore gamer.

    Keep up the good work, and PLEASE do keep us informed on at least these Intel SSD drives :)
    Reply
  • BD2003 - Monday, September 08, 2008 - link

    If the achilles heel of the JMicron MLC is the random write speed, why couldnt a ram buffer be used to cache writes? Sure this would cause a serious problem if the power went out, but thats an issue some would be willing to live with.

    I'm fairly sure vista has an option for this in the device manager in the properties tab of a drive - "enable advanced disk performance". I wonder if that would have any effect on the results?
    Reply
  • DigitalFreak - Monday, September 08, 2008 - link

    Yet more proof that JMicron products are shit. Reply
  • ggordonliddy - Monday, September 08, 2008 - link

    For the love of all humanity: If you are going to write for a living, please learn basic comma usage!

    It is NOT okay to just stick a comma in the middle of a sentence anytime you want. And it gives readers a headache.

    Here is just one of numerous examples of improper comma usage I've seen so far (and I've only gotten to the 3rd page!):

    "Intel certifies its drives in accordance with the JEDEC specs from 0 - 70C, at optimal temperatures your data will last even longer [...]"

    The comma before "at optimal" should be replaced with a semicolon or a period (I prefer the semicolon).

    Did you actually pass your English classes? I'm guessing that you probably did and you are just a product of our miserable public school system that refuses to hold students to any real level of accountability.


    (And BTW, your quoting system is broken. When I enter text in the Quote Text dialog and click OK, nothing new appears in the Comment compose field.)
    Reply
  • 7Enigma - Friday, September 19, 2008 - link

    Honestly man, you need to seriously relax. My personal rule of thumb for grammar is does the mistake make the understanding of the sentence difficult to comprehend.

    Writing something like, "Intel certifies its drives in accordance with the JEDEC specs from 0 - 70C, at optimal temperatures your data will last even longer [...]", while not grammatically correct is completely readable.

    If it was something like, ""Intel certifies drives to accordance with the JEDEC specs from 0 - 70C, at optimal data your temperatures will last even longer [...]", now you have a legitimate beef.

    The former can easily be forgiven, the latter makes my head hurt when I read it. Trust me, whatever you do, do not go to Dailytech.com and read the articles. Those even I get annoyed at frequently and I'm very forgiving.
    Reply
  • Anand Lal Shimpi - Tuesday, September 09, 2008 - link

    You're quite right, thanks for the heads up :) Some of the article was directly from my notes while I was working on the tests, so that's one source of unpolished bits. I know I'm far from perfect, so I do appreciate your (and anyone else's) assistance.

    Thanks :)

    Anand
    Reply
  • pkp - Tuesday, September 09, 2008 - link

    Thanks for posting, Anand. I see you're already aware of the problem, but I wanted to throw my two cents in.

    What is the usual editing process? I think a once over by a second set of eyes would have caught the bulk of the grammatical errors.

    Of course, the ultimate issue isn't commas. It's readability. However, the problem was bad enough that I'm making this comment without having even gotten through the first page of this article.
    Reply
  • JarredWalton - Tuesday, September 09, 2008 - link

    I'm often the content editor for posted articles, but often we skip that stage due to late nights and schedules. Doing a final thorough edit can require a couple hours (edit and then HTLM-ize), and when someone finishes an article at 5AM or whatever and it's an NDA type piece, delaying it any further is usually not desired by the readers or us.

    I do read all posted articles, and often I take the time to go through and fix any noteworthy errors. A few misplaced commas don't really detract from a 5000 word article, however, and depending on what else is going on I may or may not edit the text. If anyone takes the time to point out specific errors, i.e. "on page 3 you write "...." they always get corrected - at least if I see it. General complaints are much more difficult to address though, i.e. "You used passive voice and therefore you must DIE!" LOL.

    I know personally that when you write a long article with lots of testing, certain thoughts tend to appear in multiple places and the final result isn't always as coherent as I would like. Trying to "fix" problems relating to flow and readability is difficult at best, and requires more time than we generally spend. If anyone wants to make specific suggestions, though, we're open for input as always.

    Perhaps it's useful to compare the process to print publications. Magazines usually have several editors on staff whose job is solely to edit other authors' work; I can say that we don't have anyone at AnandTech in that position these days. (I edit some of the articles, but not all, and even then I make mistakes.) That's probably why we have more typos than magazines, but then we provide far more thorough coverage as well. Last I saw, most magazine hardware reviews end up being one page and ~1000 words, with a couple charts.

    At the end of the day, I get most of my detailed information from the internet. Magazines might be more grammatically correct, and they make for great toilet reading, but I don't generally depend on them as a source of credible information. I'd say it's safe to say we won't see such an in-depth exploration of SSD performance and issues in any magazine. [Now I have to prepare to have someone point me to an article in some magazine that does exactly that.]

    Cheers,
    Jarred
    Reply
  • KikassAssassin - Tuesday, September 09, 2008 - link

    Then I guess I should point you to an article in last month's issue of my favorite data storage magazine.

    http://www.solidstatedisksmonthly.com/2008/08/ever...">http://www.solidstatedisksmonthly.com/2...erforman...

    Unfortunately, their website seems to be down at the moment, but keep checking it, I'm sure it'll be back up soon (and don't be fooled by the article's title. It's actually only 23 pages without the ads).
    Reply

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