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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  • mindless1 - Thursday, September 11, 2008 - link

    Sometimes the cure is worse than the problem.
  • Gannon - Tuesday, September 9, 2008 - link

    Don't worry derek I still heart you guys! :P

    Here's some cool software to check out (they have free trial version)

    http://www.whitesmoke.com/landing_flash/free_hotfo...">http://www.whitesmoke.com/landing_flash...otforwor...

    Maybe it will help escape complaints from the grammar nazi's, I think a lot of grammar is BS anyway. Language evolves constantly. It's a flexible tool to communicate.
  • Nihility - Monday, September 8, 2008 - link

    An excellent review. The benchmark results were always confusing in the past. No one would try to explain why an SSD with seemingly superior specs can't outperform a 7200 drive in media test. Thanks for putting the time in to resolve this issue.

    As for buying a drive like that, the price is still too steep for me to consider and you definitely made it clear that buying a jmicro SSD is out of the question.
    As for further testing, I'm very interested in seeing how a good SSD performs as an external drive over USB. The robustness and sturdiness of the drive is very important for something you lug around. We all know how bad bandwidth is over USB but I wonder how the latency will fair.

    Keep up the good work.
  • kmmatney - Monday, September 8, 2008 - link

    One of the other reviews I read said this SSD's controller will learn hard drive usage patterns, and get faster over time. Any tests of this feature?
  • leexgx - Monday, September 8, 2008 - link

    not sure how thay can lern

    i did wunder why thay never put any DRAM buffer on SSD drives as i was expecting SSD to suffer badly from lack of buffer any MLC drives basicly suck (16kb buffer per flash chip) unless its the intel MLC drive lol or an SLC drive seem mostly ok, but an intel SLC going to rock when thay get tested
  • Anand Lal Shimpi - Monday, September 8, 2008 - link

    The Intel drive will learn hard drive usage patterns however it does so over an extremely long period of time, not something I could develop a test for in my time with the drive.

    Take care,
    Anand
  • whatthehey - Monday, September 8, 2008 - link

    ...that doesn't think too much about HDD performance, particularly when we're talking about insane prices. Sure, rebooting and reloading all of your apps will feel much faster. Personally, when I reboot I walk into the kitchen or bathroom, walk back a few minutes later, and I don't notice the delays. Not to mention, I only reboot about once a month (usually when nVidia releases a new driver that I need to install).

    Another major problem I have is the tests as an indication of the "real world". Take the whole antivirus thing. I hate AV software and software firewalls, which is why I don't use Norton, AVG, Avast, McAfee or any other product that kills performance, sucks up memory, and only prevents virii/trojans after an update. AV software is just a BS excuse to pay a $60/year subscription and get nags every time your subscription expires. So there's on "real" scenario I don't ever encounter.

    Archive extraction can be pretty disk intensive as well, but how often do you need to extract a 5GB archive? Okay, so let's say you're a pirate and you do that daily... great. Now you can extract faster, but you have an SSD that can only hold 14 or so large archives. It's a nice illustration of SSDs being faster, but it's completely impractical. I have a 1TB drive just for all the movies, images, music, and disc images I have floating around.

    The tests show that SSDs can help a lot, but I for one use capacity far more. Between several games, my standard apps, and Vista I think I would use most of the 80GB. Then I think of the price and I could grab a couple VelociRaptors or even four 1TB Samsung F1 drives. I'll be truly impressed when I can get at least 320GB of SSD for less than $200. Actually, it's more like I want a good SSD with a reasonable capacity for under $100. Until then I'll just stick with my slower drives and avoid worst-case situations where HDD performance is a problem as much as possible.

    The article was good, and I appreciate the info on the MLC issues with JMicron. That confirms my suspicion that inexpensive flash drives are worse than standard mechanical drives. Intel has addressed the problem, but price is now back to where we were last year it seems. I guess the real problem is that I'm just not enough of an "enthusiast" to spend this much money on 80GB of storage... not counting stuff like that old 4GB hard drive back in the day that set me back over $200. Give it a few more cycles and I think I'll be ready for SSDs.

    PS - Also, who cares about $600 CPUs when you can buy $200 CPUs and overclock to higher performance levels? I don't think we'll ever see overclocked SSDs or HDDs.
  • DerekWilson - Tuesday, September 9, 2008 - link

    i wouldn't be so sure about not seeing overclocked SSD ...

    as this article points out, intel puts a focus on reliability ... but to do so they do sacrifice performance. the voltage applied to the transistors to store data is calibrated to write the cells quickly while maintaining a good life span. a higher voltage could be applied that would allow the cells to be written faster but would reduce the number of writes that a cell could handle.

    if intel says 100gb a day for 5 years ... i don't need that by a long shot. i would be very willing to sacrifice a lot of that for more speed.

    i actually spoke with intel about the possibility of overclocking their ssd drives at idf -- it is something that could be done as it is controlled via the firmware of the drive. if intel doesn't convolute their firmware too much or if they allow enthusiasts to have the necessary control over settings at that level we could very well see overclocked SSDs ...

    which would be very interesting indeed.
  • shabby - Monday, September 8, 2008 - link

    I was so close in buying one of those ocz drives, in fact the reason i didnt buy it was because it was a special order that took 2 weeks.
    Excellent write up, especially about the jmicron/mlc "glitch".
  • OCedHrt - Monday, September 8, 2008 - link

    Any reason why the WD GP drive does so well in the multitasking test? Even better than the VelociRaptor?

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