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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  • aeternitas - Thursday, September 11, 2008 - link

    I dont know where you shop, but 100$ can get you 750GB.


    It doesnt make much of a point anyway, as flash based and typical hard drives will coexist for at least the next ten years. One for preformance, the other for storage.

    Maybe some of you are too young to remember, but it was only about 10 years ago that a 20GB hard drive cost 200$ at costco. We are a huge step in terms of the new technology from where we were before. 32 GB for 100$? Yes please. In ten years i expect to see 3+TB flash drives running over 1GBps throughput for around 200$.
  • strikeback03 - Thursday, September 11, 2008 - link

    I assume they were referring to 2.5 inch drives, as those prices are more in line with what was stated.

    Also don't forget that with the drop in $/GB of drives has come an increase in demand for storage. Ten years ago digital photography was almost non-existent, with file sizes topping out under a megabyte. Images on the web were maybe 640x480. Now we have digital cameras that average 4-6MB as JPEGs, and some can turn out images over 30MB, not counting the medium-format backs (over 100MB IIRC for the 65Megapixel Phase 1). When I was in college any movie you saw on the network was sized to fit a 700MB CD, Now HD movies can range well over that. MP3s are still the same, or you can store in a lossless format if you choose.

    Will 3TB be small in 10 years? Possibly. The key for flash completely replacing mechanical will be getting the price low enough to hold large amounts of the current data.
  • aeternitas - Saturday, September 13, 2008 - link

    Even if they were useing 2.5" drives in the example, it doesnt matter. The fact that these drives will be replaceing 3.5" ones makes their point just as misguided in the point they were trying to make.

    Laptop and desktop drives were differant due to size, now they arnt, so you cant comapair them (HDD vs SSD) in such a illogical manner.
  • Blimeynext - Friday, April 23, 2010 - link

    "Intel went one step further and delivered 5x what the OEMs requested. Thus Intel will guarantee that you can write 100GB of data to one of its MLC SSDs every day, for the next five years, and your data will remain intact."

    Any tool out there which tells me how much I write to my HDD each day? It would be nice to find out my present usage and compare it with the 100 GB/day limit....

    If I write less than 20GB a day does that mean the SSD will last at least 25 years?
  • Smokerz - Sunday, January 2, 2011 - link

    http://www.bit-tech.net/hardware/apple/2010/07/01/...

    read it all
  • Smokerz - Sunday, January 2, 2011 - link

    sorry for the misspell

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