Understanding SandForce's SF-1200 & SF-1500, Not All Drives are Equal
by Anand Lal Shimpi on April 16, 2010 11:30 AM ESTIt’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.
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superjojo - Friday, April 16, 2010 - link
I'm sorry if I'm mistaken, but while reading the article I had a feeling that Anand was kind of retaliating against SandForce for something they might have done/said at that meeting.Anand Lal Shimpi - Friday, April 16, 2010 - link
I'm not sure what's shipping to OEMs right now, but the Vertex LE is the only thing I can point at as being a SF-1500 without the supercap and some of the other enterprise features.There are more SF-1500 devices in the pipeline, but the focus is on SF-1200 as the full 1500 solution is quite pricey.
Take care,
Anand
arehaas - Saturday, April 17, 2010 - link
OCZ Vertex 2 is advertised as Sandforce-1500, and Agility 2 as Sandforce-1500. With 50,000 and 10,000 write IOPs, respectively. They have been available in Europe for two weeks already.arehaas - Saturday, April 17, 2010 - link
Sorry, a typo - Agility 2 is Sandforce-1200.SirZ - Friday, April 16, 2010 - link
Why on earth would a business want to "throttle" their product? They could make all these "business" problems go away just by giving everyone the exclusive firmware (with the power saving thing fixed, in MP mode). There has to be a better way to reward the company that stood by you from the start (OCZ) than punishing everyone else. Why not just give them a better deal? OCZ wins, customers win.Mr Perfect - Saturday, April 17, 2010 - link
I think the problem is who SandForce perceives their customers to be.The drive OEMs may be the one's writing checks to them, but it's ultimately the end user who is creating the demand.OCZ certainly should be given something extra for helping SandForce develop the tech, but giving them a SF-1200 that outperforms all other SF-1200s is at best confusing, and at worst deceptive. Give them a new SKU if you really must give them a performance edge. Call it a SF-1300 or SF-1400, and the consumer won't feel like they are being mislead.
SirZ - Friday, April 16, 2010 - link
Right now, they all lose. I have been getting ready to jump on the real SSD bandwagon (bought a 30 GB Vertex a couple months ago, still sitting in the box, to small for anything useful, call it a 90 dollar impulse buy), and this Sandforce thing has been promising, and I have been favoring some flavor of the Vertex (the cheaper ones anyway), but this silliness about sending the "better" performing product to review sites, makes me suspicious and is pushing me closer to Intel's drive. (If only it was 10-15% cheaper...)So, OCZ, Sandforce, etc... you all lose. Thanks Anand, and double thanks for not caving in to the usual corporate pressure to keeping this stuff hush-hush (I know how these review things go ;)
willscary - Friday, April 16, 2010 - link
It took a bit over 1/2 hour and being put on hold twice, but I finally got a straight answer. The 3 Mercury Extreme SSDs that I bought on Monday under the premise and specifications of the Sandforce 1500 controller do NOT have the 1500 controller, but instead the 1200 controller.I was given no explanation other than "All Mercury Extreme SSDs now shipping have the Sandforce 1200 controller onboard"
OWC had no problem offering an RMA for these drives, but I still feel cheated. The cost of the lesser controllers means that the drives should have been cheaper, but OWC decided to try to pull a "bait and switch" and pocket the extra cash. I will now be ordering OCX Vertex LEs.
Again, thank you Anand for this article. While performance may be equal, I want to know what I am buying and get what I paid for. This article, along with a quick change to the OWC website this morning, turned on the lightbulb.
Its too bad. These are probably still superb drives, but the fact that I was really misled on the components leaves me feeling like OWC attempted to get away with robbery. Luckily, as soon as caught, they are quick to comply with an RMA to make themselves look like it was a mistake, but the person on the other end of the phone was CLEARLY annoyed as he quickly sent the RMAs.
Ipreferspam - Friday, April 16, 2010 - link
Do you know what SF-1200 firmware the OWC drives are shipping with?ggathagan - Friday, April 16, 2010 - link
Perhaps at least some of your ire should be directed at Sandforce, not OWC.Remember that the difference comes down to firmware and put yourself in OWC's place:
Do you continue to ship Extreme SSD's with the RC firmware and hope that you don't have any reliability issues, or do you use the MP firmware?
Given that they weren't privy to the special agreement that OCZ was, they will not be receiving MP firmware for the 1200 with the higher specs.
Having decided to go with the MP firmware for reliability's sake, at what point do you suggest that they change the published specs?
Granted, it would have been nice if they sent an email to all whose purchase might have been impacted, but given that they were more then willing to RMA the drives, I fail to see how bait-and-switch comes in to play.