It’s a Mad World: Not All SF-1200s Perform Alike

OCZ was the first from our community to really embrace SandForce. It’s my understanding that the two companies have a very close relationship, and OCZ has committed a lot of resources to SandForce and its products. OCZ took the early risk that others would not. While other companies are working with SF today, OCZ appears to have been the first from the SSD makers we cover on the site.

In exchange for their cooperation and support, SandForce gave OCZ a couple of things. First was the unique SF-1500 used in the Vertex LE at competitive prices (and minus some of the enterprise features). This gave OCZ a huge head start on the competition. The second thing SandForce gave OCZ was the rights to an exclusive firmware for the SF-1200. This firmware would give OCZ the small file random write performance of the SF-1500, but with the rest of the feature set of the SF-1200. This special firmware is going to be used in the upcoming Vertex 2 SSD.

The rest of SandForce’s customers would get the standard SF-1200 firmware, which allows the drive to run at 10,000 sustained 4K random IOPS. Other SF-1200 drives from OCZ, such as the upcoming Agility 2, would also use this standard SF-1200 firmware. The special firmware is only for the Vertex 2 at this point.

SandForce’s firmware has been in release candidate (RC) stage for the past couple of months. Internally SandForce calls this version 3.0.1 and has communicated to all of its partners what RC vs. MP (mass production) firmware entails:


This slide is shared with all SF partners.

Two things are true about this RC firmware: 1) it doesn’t limit small file random write speed on the SF-1200, and 2) there is a known reliability issue that could result in a dead drive (similar to what happened to my Vertex 2 Pro earlier this year).

And here’s where things get messy. SandForce distributed 3.0.1 to all of its partners (so much for that exclusivity agreement), and some of its partners have decided to sample reviewers or even ship based on 3.0.1. Note that even OCZ’s Vertex LE shipped using the SF-1500 version of this firmware. If SandForce indeed distributed the above slide to all of its partners, no drive should've shipped with RC firmware. That's a separate issue entirely and I've been working with both SandForce and the companies involved to see what we can do about curbing this (or at least get me the information so that I can make it clear when a product is using non-MP firmware).

The Corsair Force drive that has been sent out for reviews and that’s currently shipping today uses SandForce’s 3.0.1 firmware.

Naturally, I called up Corsair to figure out what’s going on. Corsair explained to me that the reliability problem was related to a power saving feature on the controller that Corsair simply disabled and thus avoided the issue entirely. I have yet to find a repeatable way to reproduce the bug, but the power data from our testing corroborates what Corsair is saying:

Corsair’s drive uses more power than OCZ’s Vertex LE. While it could be for a number of reasons, it’s apparently due to this power saving feature being disabled. Unless I’m wrong, Corsair appears to have circumvented the known reliability issue and is shipping product it feels is safe into the market.

Now we get to the other problem. The performance of 3.0.1 is the same as OCZ’s exclusive SF-1200 firmware, because the firmwares are the same. However SandForce has recently released its first MP firmware: 3.0.5. This firmware, as you’d expect, caps small file random write performance on all SF-1200 drives except for the Vertex 2 in accordance with SandForce’s agreement with OCZ. The SF-1500 version of this firmware doesn’t change performance, but it does supposedly fix the reliability problems and is available for Vertex LE owners here.

Corsair is currently testing the 3.0.5 revision for its drive but hasn’t shared it with me yet. Corsair wasn’t aware that performance dropped with this revision until I called yesterday. The release notes don’t indicate anything of the sort, Corsair was kept completely in the dark on this. Why didn’t SandForce tell Corsair? Because although it drops performance, the new firmware still runs the SF-1200 at its intended spec. The chip will continue to perform as advertised, just slower than with the RC firmware and slower than OCZ’s Vertex 2.

SF-1200 vs. SF-1500 Where Do We Go From Here?
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  • Dazex - Friday, April 16, 2010 - link

    Articles like these is what make Anand stand out from other tech blog and the reason why I value his take on hardware, even if it's an Apple dock. His experience and thinking adds great insight into all his articles.

    Thanks.
    Reply
  • Spivonious - Friday, April 16, 2010 - link

    +10000000000

    Keep up the fantastic work, Anand!
    Reply
  • vshah - Friday, April 16, 2010 - link

    Its good to know that we have people looking out for us who are willing to bring it up with companies when there are issues like these. keep it up! Reply
  • 7Enigma - Friday, April 16, 2010 - link

    Anand,

    Can you wager a guess at how the performance will be hampered by cutting the random write IOPS by 2/3rd's?
    Reply
  • willscary - Friday, April 16, 2010 - link

    Yes, I always read his articles. I only wish this article would have appeared prior to OWC changing their specs this morning. Now I am wondering. The site still calls it an "Enterprise" class unit, but yet went from the higher specs of the 1500 to the lower specs of the 1200 across the board. Although it may end up meaning nothing...I am still worried that it could make a difference if I recieve the 1200 instead of the 1500 controller units, and I really feel a bit cheated by OWC at the moment, although I have not yet received the units. The first two should be here within an hour or so. The 3rd, a 200GB model, has not yet shipped. Reply
  • Anand Lal Shimpi - Friday, April 16, 2010 - link

    I specifically asked SandForce this question yesterday and they answered saying that they had no idea what chips OWC purchased for the Mercury drives. That floored me.

    In any case, I've contacted OWC and I'm waiting for their reply. I will also update the OWC review with a warning to anyone making any purchasing decisions today.

    Take care,
    Anand
    Reply
  • willscary - Friday, April 16, 2010 - link

    Anand,

    This was not directed at you and I apologize if my writing skills made it look that way. I have begun installing SSDs in all of our new computers based on your articles. The Crucial M225 SSDs that I had been using had a 5 year warranty, just as the Mercury Extreme.

    What made me decide on the OWC SSDs on these 3 computers was the added reliability and reduced data loss of the 1500 controller. These were theoretical specs, but they sounded promising enough to put my faith in OWC. It was a tosup between them and OCZ, but I read many good things about the people at OWC and decided to give them a chance.

    I only hope that my 3 units will contain the 1500 controller. When I purchased them, their website touted the 1500 specs listed in this article. Now the OWC site lists the specs for the 1200. The rediced data loss chances of the 1500 were what drove me to this SSD over the Crucial.

    Thanks Anand! Keep up the great work!
    Reply
  • Anand Lal Shimpi - Friday, April 16, 2010 - link

    Oh I didn't take it as directed at me at all :) I was just sharing your frustrations.

    We'll get to the bottom of this one way or another.

    Take care,
    Anand
    Reply
  • willscary - Friday, April 16, 2010 - link

    In the mean time, I will not open the packaging of the two that will be here in the next half hour or so. Reply
  • Anand Lal Shimpi - Friday, April 16, 2010 - link

    I have confirmed with OWC, the specs have changed. The Mercury Extreme is now a SF-1200 based part with lower IOPS. I asked OWC to consider changing the name given that the controller has changed, we'll see what happens.

    If you have any questions/issues/concerns I can put you in touch with someone over there that can help you deal with your order. Email me for more info :)

    Take care,
    Anand
    Reply

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