Second-Gen SandForce: Seven 120 GB SSDs Rounded Up

How Can Seven SandForce-Based SSDs Differ?

At first glance, there's very little physical difference between these 120 GB SandForce-based SSDs. And yet, the least- and most-expensive models are separated by $100!

When you dig deeper into these drives' internals, though, there are some significant differentiators. The SSDs employ a couple of NAND flash technologies, for example. They also incorporate firmware tweaks to optimize certain specifications.

OCZ's Agility 3 120 GBOCZ's Agility 3 120 GB

OCZ's Vertex 3 120 GBOCZ's Vertex 3 120 GB

Understanding Memory Technology

NAND flash manufacturers are tasked with addressing two issues: memory density and performance. The former gets handled almost automatically when lithography nodes advance. Obviously, smaller transistors let you put more memory cells into the same amount of space. Despite the fact that progressively smaller geometry complicates the issue of write endurance, reducing the number of program/erase cycles a given cell can tolerate, the recent shift from 3x nm to 25 nm flash is an absolutely necessary step in lowering the cost per gigabyte we all have to pay for solid-state drives.

But increased storage density is only part of the evolution happening behind the scenes. Each generational step of memory technology also sees better performance. This is masked, for the most part, by the fact that SSD controllers use multiple memory channels to aggregate throughput. But now that we're dealing with 6 Gb/s SATA drives theoretically able to move more than 500 MB/s, the data rate of each channel actually matters. 

Most manufacturers are using the latest synchronous technology to facilitate the best possible performance. However, others are designing less expensive models employing older and more affordable asynchronous NAND. Take Intel's second-generation X25-M as an example. The drive employs modules compliant with the ONFi 1.0 standard operating at 50 MB/s per channel. A fully populated 10-channel controller offers enough aggregate bandwidth to more than saturate the SSD's 3 Gb/s controller. And even if Intel's proprietary controller were 6 Gb/s-capable, there's a good chance its 10 channels would be ample.

But the SandForce architecture we're evaluating today uses eight channels. And given the highest sequential numbers cited by each vendor, eight 50 MB/s channels simply wouldn't suffice in situations where SandForce's technology couldn't apply significant compression and deduplication to the data. That's why the highest-performing drives in this story use newer memory types. In this story, the fastest drives just so happen to employ Toshiba's synchronous Toggle Mode 1.0 DDR NAND. SSDs based on the second-gen synchronous ONFi standard comprise the next pack. And the least-expensive drives use asynchronous first-gen ONFi-based memory.

Although much is made of the Toggle Mode (from Samsung and Toshiba) and ONFi (Intel and Micron) interface standards, it's really only a format war, and not something end-users should have to sweat. The more telling indicator of performance is whether the memory is asynchronous or driven by a clock signal (synchronous). The following slide from Bob Pierce's 2010 Flash Memory Summit presentation helps illustrate the gains from using synchronous devices. Although Bob was talking about SLC NAND, the same gains are typical of MLC-based devices, too.

Performance: Async vs SyncPerformance: Async vs Sync

Of course, increased performance translates into higher cost. The memory itself costs more because NAND manufacturers have to synchronize it with a reference clock. Asynchronous NAND is less expensive, but you pay that penalty of lower performance.

Today's most popular SSD controllers from Intel, Marvell, and SandForce are agnostic in that they support synchronous and asynchronous memory. As you can see in the block diagram of the SF-2200 above, SandForce gives SSD vendors plenty of choice in the way they configure their drives, and that's really the most obvious way drives get set apart. These guys aren't just taking the same controller, dropping it onto a reference PCB and mating it to the least-expensive NAND available at the time.

We see vendors like Corsair and OCZ using the same controller, but then creating differentiated product lines by picking the right flash memory and tweaking their respective firmware. That's the story behind drives like the synchronous-based Vertex 3 and Force Series GT, which cost more, and the less expensive Agility 3/Force Series 3, which use asynchronous memory.

While SandForce-based drives look alike based on their spec sheets, performance understandably varies quite a bit.

Brand
Adata
Corsair
Mushkin
OCZ
OCZ
OCZ
Patriot
Model
S511
Force Series 3
Chronos Deluxe
Vertex 3
Agility 3
Solid 3
Wildfire
NAND Type
Sync
AsyncSync
Sync
AsyncAsyncSync
Number of NAND Devices
16
16
8
16
16
16
16
Dies Per NAND Device
1
1
2
1
1
1
1
Standard
ONFi 2.0
ONFi 1.0
Toggle Mode DDR
ONFi 2.0ONFi 1.0
ONFi 1.0Toggle Mode DDR
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  • dauthus
    The Corsair force series 3 drives should be instantly disqualified due to BSoDs etc. Go look at their reviews on newegg, it is horrifying.
    6
  • garage1217
    Nice review. You left out the corsair Force GT 120gb however which would have compared equally to the vertex as other sites have scored it. Also I own one, it ROCKS.

    On the force 3, it got horrible reviews because of a production issue. Corsair issued a full recall and now the issues with that particular drive have been cleared up which is why it was not disqualified. Very old news.
    0
  • dauthus
    Quote:
    On the force 3, it got horrible reviews because of a production issue. Corsair issued a full recall and now the issues with that particular drive have been cleared up which is why it was not disqualified. Very old news.


    You are wrong sir.
    5
  • gregzeng
    Googling told me that SSDs are almost impossible to use with Linux (EXT4). My netbook & notebook drives are in MS NTFS-COMPRESSED partitions (not Linux NTFS-4G, 'cos no compression). MS claims compressions has 'negligible' speed costs. Is that true, for about twice then storage space?
    2
  • mayankleoboy1
    why not include the max iops editions?
    anands benchies showed that 120gb vertex3 max iops ~= 256gb vertex 3 for quite a less price
    0
  • Hellbound
    This article mentions installing the OS and applications to SSD, and the rest (movies, music) to conventional hdd's. But I'm not sure how to do that. I've google'd it and there are many suggestions how to do it. I would like to know the best way to go about this.
    0
  • whysobluepandabear
    HellboundThis article mentions installing the OS and applications to SSD, and the rest (movies, music) to conventional hdd's. But I'm not sure how to do that. I've google'd it and there are many suggestions how to do it. I would like to know the best way to go about this.

    WTF?

    Step 1.) Install SSD.

    Step 2.) Install OS on SSD and everything you want to access and run quickly.

    Step 3.) Install HDD.


    Step 4.) Send files to E, F, G, H, I, J or whatever drive the HDD is. Performance orientated apps go to the C, or whatever drive your SSD is.


    It's literally no different than if you were to plug in an external HDD via USB. You direct files and applications as accordingly.

    We'll dismiss the Z68 - which allows you to use a small SSD to boost your normal HDD - otherwise if your SSD is large enough, it's actually a worse route, and just instead use the SSD.
    3
  • flong
    This is a superb review because it deals with real-world performance. I commend Tom's for providing a thorough review - one of the most thorough that I have read on any computer site. Tom's is right, the 120 GB size SSD is the sweet spot in SSD drive performance Vs cost.

    If you read similar reviews on other sites, the Patriot Wildfire, The Corsair Force 3 GT and possibly the OCZ Vertex 3 are the top performers in the 120 GB drive performance. The Wildfire uses 32 NM Toshiba toggle flash memory which is the best. The Force 3 GT uses 25 NM memory but somehow manages to keep up with the Wildfire. Note this is not the Corsair Force 3 listed in this review, it is the Corsair Force 3 GT - emphasize the GT. The GT and the wildfire are the two fastest 120 GB drives available right now based on real-world performance benchmarks.

    The real important benchmarks to watch for are the real-world benchmarks at the end of each review. These really are the only ones that count. The other benchmarks are synthetic and they are not very accurate. The OCZ drives win all of the synthetic benchmarks but their real-world performance falls behind the Force GT and the Wildfire.

    Another critical factor is that "fill-rate" performance of the drives. This is the performance of the drives as they fill. Again, the Wildfire and the Force GT rise to the top with the Vertex 3 coming in third place.

    This review lists the Mushkin as a top performer, but it is not listed in many reviews (none that I have read) and so I have not included it in my comments. It is possible that this is a top performer also but I would like to read other reviews about it to confirm.
    1
  • Anonymous
    Same thing with OCZ, to be honest. They got an error rate of 33% over at Newegg. Honestly I won't buy a single drive from them, no matter how fast, until they've fixed their issues that have lasted for two bloody generations.

    Crucial m4 for performance and Intel 320 for value is the best.
    6
  • compton
    HellboundThis article mentions installing the OS and applications to SSD, and the rest (movies, music) to conventional hdd's. But I'm not sure how to do that. I've google'd it and there are many suggestions how to do it. I would like to know the best way to go about this.


    Besides just manually managing your files on the HDD, there is another method you can use. It's more complicated to set up, but if you can google and follow directions, you'll find it may be easier.

    With Windows 7 you can basically take your "My Documents" folder (the \Users\ stuff) and symbolically link the folders to the mechanical HDD. Everytime an application wants to save to one of your document folders, which would otherwise be on your system drive (in this case a SSD) will just end up on the HDD. From a file management perspective, you may find it easier.

    I do it manually -- just install Windows, Office Pro 2010, Pantone, Google Chrome, iTunes, ect. to the SSD. All of my music, movies, backups of my SSD (I'm only using about 22GB of my Intel 510's 111GB) end up on the HDD. My Steam folder is about 200GB as well, so it goes on the HDD.

    You just have to do stuff like change iTunes folder in advanced options to the folder on the HDD. It's really easy to do. That way, when I want to use another SSD, I have all the Steam games and media on the HDD. Fresh installs are really easy this way.

    I tried installing some of my games on a few of the SSDs I own. Some games can really benefit, but mostly the increase in speed over a fast HDD isn't worth it.

    I bought an original WD Raptor 36GB drive in 2003 that I used for many years, so I was completely comfortable trying to manage the stuff that ends up on my HDD. I ended up moving from a 60GB SSD to a 120GB SSD that is faster but I just can't bring myself to put much on it.
    2
  • chovav
    nice work guys :)

    I do have a question though: for my own use, I need to encrypt the system drive using TrueCrypt (128bit AES). When I did that on a Vertex 2 60GB, the performance went down a hundred-fold! This apparently had to do with the fact that the data was in-compressible (bad for SandForce controllers) and the drive was completely "filled" by TrueCrypt's encryption (so you won't be able to see how much data is on it).

    This meant that the performance was actually LOWER than an encrypted mechanical hard drive, and actually almost unusable. Is there any way for you to devise a test that looks at this effect on SSD performance? This situation is not very rare, a lot of business users must encrypt their drives in order to comply with Company Policy..

    I've used AS-SSD for testing, with read/write results at around 3.5MB/s :S

    Thank you,

    Chovav
    0
  • brenro
    Tiger Direct's selling the Solid 3 for $165. That's only about 50 bucks more than a Velociraptor. I think it might be time to pull the trigger. Are these things reliable enough now to use them as the only drives in a RAID?
    0
  • aznguy0028
    garage1217On the force 3, it got horrible reviews because of a production issue. Corsair issued a full recall and now the issues with that particular drive have been cleared up which is why it was not disqualified. Very old news.

    Nope, I had a new force 3 120gb, model 1124 (which was the one that is supposedly fixed), and I was still getting BSODs so I returned it. I waited for the whole early fiasco to be over but still had problems. Go check the Corsair forums, tons of people are still having issue. I'm staying away from any ssd that is using the SF 2281 but I'm keeping my eye on the Wildfire to see how reliable that one is.
    1
  • garage1217
    Rocking mine just fine with no bsods or issues of any kind and tons of others are rocking their 120gb force drives with no issues. The editors of this review did not find or have issues as well, nor have other reviewers since the recall. So does that tell you anything at all?

    Sort of comes down to that old story about the girl that just cannot keep a man. She complains and moans about how it is always the guys fault or she cannot find the right guy and they all suck. She never thought it was her retarded self that was the real issue things never worked out lol So along those lines, have you ever considered it is YOUR equipment and setup, not the drive that is causing the issue? I hear crap like this every day from people with oc'ed systems that they claim is stable when it really is not causing issues that really show themselves with ssd drives. Or people that really have no clue what they are doing in the bios mucking things up and causing problems that may be tolerable to one piece of equipment and not another so when they switch, issues arise. Or a ton of other combos of crap that just do not workout at all together like a junk power supply causing instability issues, or trying to install the latest equipment on quite old hardware.

    Bottom line, I am not seeing any issues at all, tons of others are not seeing any issues and if you care to look at other reviews on say newegg of other brands, you will find the same thing across all ssd manufacturers, not just one in particular. You also find the same thing with mobos, standard drives, optical drives, power supplies, video cards. Really throws up red flags when the person claims in a review "i have tried 5 of these and not a one works!!!" Duh morons, wake up and realize what the real issue is, a lack of troubleshooting skills and the knowledge to properly use a device.
    -2
  • acku
    SSDs are more problematic than just about every other piece of hardware. It's like a Jenga puzzle, you remove one block and something else goes wrong. Just look at the Solid 3 and Agility 3. Identical hardware, different performance due to firmware.

    That said, I believe that each SSD manufacturer is experiencing their own unique issues. I personally haven't experienced any BSOD issues in the lab. As an example, our workstations are allowed to sleep, which has been a cited issue with the new OCZ SSDs. Anand has the same experience - no BSOD errors in his lab. That's a similar sentiment shared by other reviewers.

    Overall, SSDs are kind of like cars. You may experience something on the road, but once you bring it to your mechanic, nothing seems wrong. Problems with SSDs are highly correlated with configuration and how they are used (what is written, how fast it is written, how much is written, etc...). And I'd go so far as to chalk 99% of the "soft errors" to be related to the flash translational layer (FTL).

    If you're looking for rock solid reliability, you're better off with a hard drive. It doesn't matter if you own a hard drive or a SSD, everyone should practice good backup practices.

    Cheers,
    Andrew Ku
    Tomshardware.com
    -1
  • banthracis
    Current Cost per GB on newegg for the reviewed drives

    OCZ agility 3 120gb $1.50/gb (includes rebate. $1.75/gb without )
    OCZ solid 3 120gb $1.62/gb (includes rebate. $1.79/gb without)
    Crucial M4 128gb/256gb $1.67/gb
    Corsair Force 3 120 $1.75/gb
    Intel 320 120gb $1.83/gb
    AData s511 120 $1.91/gb
    OCZ Vertex 3 120 $1.91/gb (includes rebate. $2.08 without)
    Mushkin Chronos Deluxe 120gb $2.16/gb
    Intel 510 120gb $2.30/gb
    Patriot wildfire 120gb $2.50/gb

    Going through your benchmarks, it actually looks like the Crucial M4 drives are the best choice with consistent good performance and very low cost/gb.
    In fact, the 256 gb M4 particularly stands out for having the same $/gb as the 120gb M4, yet top of the pack performance throughout the benchmarks.

    Edit: Forgot the Deluxe in Mushkin Chronos. Price/gb was correct though.
    0
  • acku
    That's because we test with 4kb transfer sizes in random accesses. The 256 GB and 512 m4s have a native 8kb page. We're going to cover all of that in another article dedicated to m4s.

    If you want nothing to do with compression and still want a performance SSD, m4s are probably the best choice. That's why they're often included in the best SSDs for the money.

    FYI, we used a Chronos Deluxe ~= Wildfire. The regular Chronos is the async stuff, same as Force 3 and regular Vertex 3.

    Cheers,
    Andrew Ku
    TomsHardware.com
    0
  • garage1217
    Anonymous said:
    SSDs are more problematic than just about every other piece of hardware. It's like a Jenga puzzle, you remove one block and something else goes wrong. Just look at the Solid 3 and Agility 3. Identical hardware, different performance due to firmware.

    That said, I believe that each SSD manufacturer is experiencing their own unique issues. I personally haven't experienced any BSOD issues in the lab. As an example, our workstations are allowed to sleep, which has been a cited issue with the new OCZ SSDs. Anand has the same experience - no BSOD errors in his lab. That's a similar sentiment shared by other reviewers.

    Overall, SSDs are kind of like cars. You may experience something on the road, but once you bring it to your mechanic, nothing seems wrong. Problems with SSDs are highly correlated with configuration and how they are used (what is written, how fast it is written, how much is written, etc...). And I'd go so far as to chalk 99% of the "soft errors" to be related to the flash translational layer (FTL).

    If you're looking for rock solid reliability, you're better off with a hard drive. It doesn't matter if you own a hard drive or a SSD, everyone should practice good backup practices.

    Cheers,
    Andrew Ku
    Tomshardware.com


    I will agree to that :) SSD drives in general are not perfect, but they are not the horrid plague that some make them out to be.
    -1
  • acku
    Anonymous said:
    nice work guys :)

    I do have a question though: for my own use, I need to encrypt the system drive using TrueCrypt (128bit AES). When I did that on a Vertex 2 60GB, the performance went down a hundred-fold! This apparently had to do with the fact that the data was in-compressible (bad for SandForce controllers) and the drive was completely "filled" by TrueCrypt's encryption (so you won't be able to see how much data is on it).

    This meant that the performance was actually LOWER than an encrypted mechanical hard drive, and actually almost unusable. Is there any way for you to devise a test that looks at this effect on SSD performance? This situation is not very rare, a lot of business users must encrypt their drives in order to comply with Company Policy..

    I've used AS-SSD for testing, with read/write results at around 3.5MB/s :S

    Thank you,

    Chovav


    I actually hadn't thought of using TruCrypt with a SSD. But your experience with a SandForce drive makes a lot of sense. Near to no compression being done, which is horrible for SF's garbage collection which relies on "extra" space made available by compression. Basically, you're completely throttling the drive and every write leaves little to no time for idle garbage collection because everything written is encrypted. This would be the same as running Iometer with completely random data over the course of weeks at a time. That's why performance is going to be better on a hard drive. I'd recommend trying an m4 if TruCrypt is a must.
    0
  • mariush
    gregzengGoogling told me that SSDs are almost impossible to use with Linux (EXT4). My netbook & notebook drives are in MS NTFS-COMPRESSED partitions (not Linux NTFS-4G, 'cos no compression). MS claims compressions has 'negligible' speed costs. Is that true, for about twice then storage space?


    The compression algorithm used by the NTFS system can at best compress text and various uncompressed stuff down to about 50% of the original size, with little CPU usage.

    It will not compress at all the most often found files such as mp3, avi, mkv, docx, which are already compressed. Also, the majority of games' files are already compressed so enabling NTFS compression really won't save a lot of disk space.
    0