SandForce TRIM Issue & Corsair Force Series GS (240GB) Review
by Kristian Vättö on November 22, 2012 1:00 PM ESTThe Corsair Force GS
Now that the TRIM issue is out of the way, it's time to take a closer look at Corsair's Force GS SSD. Not much has happened in the SandForce SSD frontier for a while and the Force GS isn't exactly special either. As with most SandForce based SSDs, it's based on SandForce's SF-2281 controller, although Corsair has chosen SanDisk, a bit more uncommon choice, as the NAND supplier. SanDisk's NAND uses the same Toggle-Mode interface as Toshiba's and Samsung's NAND, which is rarer in SandForce SSDs than ONFi NAND. That's not to say that the Force GS is the first Toggle-Mode NAND based SandFroce SSD; there are quite a few that use Toggle-Mode NAND as well, such as OWC's Mercury 6G and Mushkin's Chronos Deluxe.
| Comparison of NAND Interfaces | ||||||
| ONFi | Toggle-Mode | |||||
| Manufacturers | IMFT (Intel, Micron, Spectec), Hynix | Toshiba/SanDisk, Samsung | ||||
| Version | 1.0 | 2.0 | 2.x | 3.0 | 1.0 | 2.0 |
| Max Bandwidth | 50MB/s | 133MB/s | 200MB/s | 400MB/s | 166MB/s | 400MB/s |
By using Toggle-Mode NAND, Corsair claims to achieve slightly higher write speeds than ONFi based SandForce SSDs, although the difference is only about 5MB/s in sequential write and 5K IOPS in 4K random write. While SanDisk NAND is quite rare, it should not be of lower quality than any other NAND. Toshiba and SanDisk have a NAND joint venture similar to Intel's and Micron's IMFT: SanDisk owns 49.9% and Toshiba owns the remaining 50.1% of the joint venture. As the NAND comes from the same fabs, there is no physical difference between SanDisk and Toshiba NAND, although validation methods may of course be different.
| Corsair Force Series GS Specifications | ||||
| User Capacity | 180GB | 240GB | 360GB | 480GB |
| Controller | SandForce SF-2281 | |||
| NAND | SanDisk 24nm Toggle-Mode MLC NAND | |||
| Raw NAND Capacity | 192GiB | 256GiB | 384GiB | 512GiB |
| Number of NAND Packages | 12 | 16 | 12 | 16 |
| Number of Die per Package | 2 | 2 | 4 | 4 |
| Sequential Read | 555MB/s | 555MB/s | 555MB/s | 555MB/s |
| Sequential Write | 525MB/s | 525MB/s | 530MB/s | 455MB/s |
| Max 4K Random Write | 90K IOPS | 90K IOPS | 50K IOPS | 50K IOPS |
The interesting thing in Force GS are the available capacities; Corsair isn't offering anything smaller than 180GB and there is also a more uncommon 360GB model included. As explained in our pipeline article of the Force GS launch, 180GB and 360GB models are achieved by running the SF-2281 controller in 6-channel mode and using either 6 or 12 NAND packages. Corsair only had 240GB review samples available, but they promised to send us a 360GB sample once they get them.
| Price Comparison (11/22/2012) | |||||
| 120/128GB | 180GB | 240/256GB | 360GB | 480/512GB | |
| Corsair Force GS | N/A | $160 | $220 | $315 | $400 |
| Corsair Force GT | $130 | $185 | $220 | N/A | $390 |
| Corsair Neutron | $120 | N/A | $213 | N/A | N/A |
| Plextor M5S | $110 | N/A | $200 | N/A | N/A |
| Crucial m4 | $110 | N/A | $185 | N/A | $389 |
| Intel 520 Series | $130 | $190 | $234 | N/A | $370 |
| Samsung SSD 830 | $104 | N/A | $200 | N/A | $550 |
| OCZ Vertex 3 | $89 | N/A | $200 | N/A | $425 |
| OCZ Vertex 4 | $75 | N/A | $160 | N/A | $475 |
| Mushkin Chronos Deluxe | $100 | N/A | $180 | N/A | N/A |
Force GS is priced competitively against other SSDs at all capacities. All capacities are priced noticeably below $1 per GB, even the not so common 180GB and 360GB models. Of course, it should be kept in mind that SSD prices change frequently (e.g. some of the models like the 480GB Vertex 3 have dropped in price by 30% or more in the past two months!), so you should do your own research before buying. We can only quote the prices at the time of writing, there is a good chance that our pricing table will be at least somewhat out of date in less than a week.
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JellyRoll - Saturday, November 24, 2012 - link
Entertaining that you would link to thessdreview, which is pretty much unanimously known as the home of misinformation. Here is a link to the actual slide deck from that presentation, which does not ever mention deduplication.http://www.flashmemorysummit.com/English/Collatera...
CeriseCogburn - Saturday, December 29, 2012 - link
LOL - good job, I will continue to read and see if all the "smart" people have finally shut the H up.I was hoping one would come by, apologize, and thank you.
Of course I know better.
*Happy the consensus is NOT the final word.*
dishayu - Friday, November 23, 2012 - link
Get Kristian on to the next episode of the podcast and make him talk!!popej - Friday, November 23, 2012 - link
What exactly does it mean: "I TRIM'ed the drive after our 20 minute torture"?Shouldn't TRIM function be executed by OS all the time during torture test?
Kristian Vättö - Friday, November 23, 2012 - link
Most of our tests are run without a partition, meaning that the OS has no access to the drive. After the torture, I created a partition which formats the drive and then deleted it. Formatting the drive is the same as TRIMing all user-accessible LBAs since it basically tells the controller to get rid of all data in the drive.popej - Friday, November 23, 2012 - link
Does it mean, that there was no TRIM command executed at all?Not when torturing drive, because it wasn't TRIM supported partition. Not when you "TRIM'ed" drive, because it was a format.
While I agree that you can notice some weird effects, why do you describe them as TRIM problems? Sorry, but I don't know how your test could be relevant to standard use of SDD, when TRIM is active all the time.
Kristian Vättö - Friday, November 23, 2012 - link
Formatting is the same as issuing a TRIM command to the whole drive. If I disable TRIM and format the drive, its performance won't restore since the drive still thinks the data is in use and hence you'll have to do read-modify-write when writing to the drive.They are problems in the sense that the performance should fully restore after formatting. If it doesn't, then TRIM does not function properly. Using an extreme scenario like we do it the best for checking if there is a problem; how that affects real world usage is another question. With light usage there shouldn't be a problem but you may notice the degradation in performance if your usage is write intensive.
popej - Friday, November 23, 2012 - link
Basing on you test I would say, that format is not enough to restore drive performance after using it without TRIM. Quite possible that the state of the drive after torture without TRIM is very different to anything you can get when TRIM is active.It would be interesting to compare your test to real life scenario, with NTFS partition and working TRIM.
Kristian Vättö - Friday, November 23, 2012 - link
With most SSDs, formatting the drive will fully restore it's performance, so the behavior we're seeing here is not completely normal.Remember that even if TRIM is active at all times, sending a TRIM command to the controller does not mean the data will be erased immediately. If you're constantly writing to the SSD, the controller may not have time to do garbage collection in real time and hence the SSD may be pushed to a very fragmented state as in our test where, as we can see, TRIM doesn't work perfectly.
I know that our test may not translate to real world in most cases, but it's still a possible scenario if the drive is hammered enough.
JellyRoll - Friday, November 23, 2012 - link
If the majority of your tests are conducted without a partition that means none of the storage bench results are with TRIM?