This post is a guide to my top recommendations for SSDs. As new models become available, this post is updated to reflect the best SSD options on the market. I also have a variety of articles about SSDs that can be accessed in the archives. Although originally published in February 2012, the date reflected on the article is the date of the last update.
Top Professional SSD Controllers
Overall, the best SSD chipsets on the market for performance seems to be the Samsung chipsets and the SandForce chipsets. There were previously SATA 3Gb/s and SATA 6Gb/s options but all slower options have vanished. In addition, another consideration is now mSATA SSDs, and PCI Express SSDs. If you want a drive that uses a chipset made by someone other than SandForce or Samsung, the best current option is the Crucial M500 SSD line. The fact that Intel is continuing to use the SandForce chipset (with their own custom firmware) also validates how good the SandForce design really is.
Some notes on why SSD capacities are different between product lines
The design of the SandForce chipset uses on-the-fly compression and extra flash memory to keep things running fast. That is why all SandForce designs are listed as lower capacity than the actual amount of flash memory in the SSD. For example, a SandForce-based SSD will actually have 256GB of flash memory but will be listed as 240GB because the extra flash memory is used by the chipset to attain the amazing performance levels and provide garbage collection even on systems where TRIM is not supported.
This capacity reporting trend has also now extended to many of the other SSD manufacturers because, as NAND manufacturing continues to move to smaller processes, additional NAND capacity is used to balance the potential downsides. An example of this trend is Crucial's M4 SSD line (using 25nm NAND) where capacities were available in typical 64GB to 512GB sizes as compared to the newer Crucial M500 SSD line (using 20nm NAND) and capacities of 120GB, 240GB, 480GB, and 960GB.
Although most SSDs on the market have more intelligent garbage collection algorithms now than they used to, I still recommend that everyone enable TRIM (Wikipedia article) on their systems. Some systems have no TRIM support as of yet (i.e. OpenBSD). Some automatically enable TRIM support (i.e. recent Linux distributions) while others require explicit enabling of TRIM (discard fstab option in Linux). OS X also only enables TRIM on Apple-provided SSDs but a quick search for OS X enable TRIM will provide some solutions that essentially zero out the vendor match in Apple's storage drivers which effectively enables TRIM for all SSDs on OS X. Although this approach for OS X worked in the past, with OS X Yosemite (10.10) it is no longer possible to load drivers that have been modified without decreasing your security settings. The good news is Apple has finally made available a way to enable TRIM on third party (non Apple OEM) SSDs as part of the OS X 10.10.4 update. This method requires using the trimforce command in Terminal. (Execute man trimforce in an OS X Terminal to get the details. The exact command to enable TRIM is sudo trimforce enable.)
What size SSD should you buy?
As pointed out in many, many articles, SSDs are faster at writes when more flash channels are available. This means that comparing a 64GB and 256GB Crucial M4, for example, will show you drastic differences in write speed. The 64GB will top out at about 100MB/s write speed while the 256GB will top out at over 260MB/s. This performance difference is a major consideration in your choice of SSD. The 60/64GB models will be the slowest. The 120/128GB will be substantially faster than a 60/64GB model but not up to the 240/256GB models. For example, a Crucial M4 128GB tops out at about 175MB/s write speed.
I also did some testing with Intel's 520 SSD line and found that, with Intel's custom firmware and a SandForce controller, write speeds decreased far less for typical benchmarks than with Crucial's M4 SSD line. However, it is still true that 240GB or larger SSDs are almost always faster for writes than any of the smaller capacities. Read speeds are often more consistent and less prone to the variations seen with write performance.
With those important points out of the way, let's move on to the available SSD models and my top three recommendations right now for 2.5-inch SSDs. I also have some thoughts on the best options for mSATA SSDs after the top three.
Samsung 840 Pro
The best all around performer with consistently amazing performance seems to be the Samsung 840 Pro with its 21nm NAND design paired with the excellent fourth generation Samsung MDX controller. Samsung is in the middle here where previous non-Samsung designs used 25nm NAND and Samsung used 27nm NAND and most of the industry is moving to 20nm NAND. As many reviews of proven, you will not be disappointed with the Samsung 840 Pro except when it comes to cost. They are still among the most expensive of consumer SSDs. This is partly because, at launch, Samsung segmented their SSD line with the high end professional 840 Pro using traditional MLC and the mainstream 840 using TLC (see below).
The Samsung 840 Pro line is fairly simple with only three capacities available. They range from the 128GB to the 256GB all the way to the 512GB.
It is also important to note that some might be confused by the newer Samsung 840 EVO series of SSDs. The 840 EVO line is Samsung's answer to Crucial's M500 line and, rather than using a more traditional approach, uses 3-bit-per-cell MLC (typically called triple-level-cell or TLC) to increase the density and decrease the cost of NAND in order to be able to provide a wide range of sizes comprised of 120GB, 250GB, 500GB, 750GB, and 1TB SSD models. The 840 EVO line is the replacement for the previous 840 (which also uses TLC) SSD line, not to the 840 Pro.
If budget is of foremost concern, the 840 EVO has received good reviews and the 120GB unit I have is functioning fine in a family computer. I would not choose the 840 EVO series for demanding uses and I would also steer potential buyers toward another SSD below.
Intel 520, 525, and 530
Although SSDs utilizing a SandForce (now LSI SandForce) controller seem to be some of the fastest on the market, there have been some bumps along the road with early designs. Intel has taken the excellent controller and written their own custom firmware which was then paired with the best 25nm NAND available to make the Intel 520 SSD series. The Intel 530 series is the successor to the 520 series and moves to 20nm NAND like the previous mainstream oriented Intel 335 series.
The 520 and 530 series are fantastic SSDs and my top pick for a SandForce-based SSD. Previously, the 520 series was far more expensive than other similar SSDs on the market even though Intel had the best SandForce firmware available. Nearly all of Intel's 520 SSDs are at or over $2/GB while the competition is much cheaper. The older 520 series was available in capacities of 60GB, 120GB, 180GB, 240GB, and 480GB. The newer 530 series is available in most of the same sizes excluding the 60GB but the 480GB model still seems to be hard to find. The amazing deal is really the 240GB model. Also be careful when ordering an Intel 530 SSD that you don't accidentally select an mSATA or a M.2 (the 80GB model for example) form factor SSD unless that's what you want. All three form factors are available in a single line this time around.
This talk of form factors brings up another line in Intel's 500 series of SSDs. The 520 series exclusively uses the 2.5-inch form factor. When Intel wanted to compete in the mSATA space, they released the 525 series which is only available in the mSATA form factor designed for netbooks, selected laptops, and in mSATA slots on some motherboards. As I mentioned above, the 530 series also provides a few models in the M.2 form factor which is the successor to the mSATA form factor and very similar to Apple's 2013 MacBook Air flash storage but Apple uses a custom connector instead of the standard M.2 connector.
The Intel 525 series comes in 30GB, 60GB, 90GB, 120GB, 180GB, and 240GB capacities. As is fairly typical, the 120GB tends to most often be the best deal. Unfortunately, as did the 520 series, the 525 series suffers from the increased cost due to the same 25nm NAND used in the 520 series. If you can find a good deal, I would highly recommend the 525 series as well. I am using a 120GB Intel 525 SSD in one of my OpenBSD systems right now.
The clear advantage with any Intel SSD is reliability and stability. No one else has been able to soundly beat Intel's SSDs on these points. Only Samsung can really challenge Intel on many of the same fronts at this time. There is also another area of SSDs where Intel has a firm foothold that I will mention shortly (see below).
Crucial M500
There is a third line of SSDs which I think are a very good offering. Crucial makes the M500 line of SSDs that are similar to the previous generation M4 line that I also recommended. Rather than the 25nm NAND (also from IMFT like the NAND in Intel 520 series), the M500 series also moves to 20nm NAND. Crucial has been very good about filling out their line quite nicely with both 2.5-inch and mSATA form factors all along. This was true of the M4 line with 32GB, 64GB, 128GB, and 256GB models along with their 2.5-inch siblings in 64GB, 128GB, 256GB, and 512GB capacities.
Now with the M500 line, Crucial is using a newer Marvell 88SS9187 controller (also used in Plextor M5 Pro/M5 Pro Xtreme) which offers very good overall performance. While Plextor was early to market with this chipset and shipped in September 2012, Crucial waited another six months or so to get to market with their solution. This allowed Crucial to use their 20nm NAND and make a larger capacity available.
This time around, Crucial was able to make 2.5-inch SATA SSDs in 120GB, 240GB, 480GB, and 960GB capacities. In addition, mSATA SSDs are available in 120GB, 240GB, and (still elusive from mainstream vendors) 480GB capacities.
With the Crucial lineup, it is easy to recognize what form factor an SSD happens to be. For example, the 120GB 2.5-inch, 7mm high model has part number CT120M500SSD1 while the mSATA model of the same capacity has part number CT120M500SSD3 where the last digit of the part number indicates whether it is a 2.5-inch (indicated by 1) or an mSATA SSD (indicated by 3). This was also true of the previous M4 lineup but, in the case of the M4 line, some SSDs came in three varieties. For example, the CT128M4SSD2 was the standard 2.5-inch, 9.5mm high 128GB SSD. The mSATA variety had part number CT128M4SSD3. The latest models were the CT128M4SSD1 models which were 2.5-inch, 7mm high SSDs. This distinction is important for systems such as the ThinkPad X230 which only support 2.5-inch SSDs with a 7mm height.
I am currently using a Crucial M500 240GB mSATA SSD in my ThinkPad X230 running OpenBSD. I am also using multiple Crucial M500 240GB 2.5-inch SSDs and an M500 960GB2.5-inch SSD as my secondary storage for my OS X laptops. All are working exceptionally well.
Enterprise SSDs from Intel
One other area I have not covered before is enterprise SSDs. In my opinion, Intel has made some exceptional designs recently with the DC S3500 and DC S3700 SSD lines. The DC S3500 series is really designed to take the excellent controller from the DC S3700 and combine with Intel's excellent standard 20nm MLC NAND to make for an exceptional value for an enterprise SSD that can allow for as much 450TB of data to be written to the SSD over its lifetime. The DC S3500 series SSDs come in 80GB, 120GB, 160GB, 240GB, 300GB, 480GB, 600GB, and 800GB capacities.
If write longevity and performance are needed at an even higher level, the DC S3700 SSD series provides for up to 15PB of data to be written to the SSD over its lifetime and uses the far more expensive 25nm high endurance MLC NAND which is referred to as HET-MLC. The DC S3700 line comes in 100GB, 200GB, 400GB, and 800GB capacities.
I have been using a 160GB Intel DC S3500 SSD as one my primary SSDs and have been very impressed. The enterprise SSDs are slightly more power hungry than you would typically want in a laptop but make great solutions for servers and important workstations. I'm planning to order more and use them in some ZFS RAID arrays and other systems in my datacenter installations.
Conclusion
I highly recommend upgrading to an SSD as your primary boot and application drive. Bulk storage is still more appropriate for hard drives but that is changing more and more. All of the product lines covered here are an excellent choice. The choice comes down to what your primary goals are.
If you are first and foremost looking for the best value while still maintaining very good performance, look no further than the Crucial M500 and Intel 530 SSD lines. If your goal is the best possible performance and the highest reliability and price is secondary, you will not go wrong with an Samsung 840 Pro and Intel 520 SSD lines.
Another metric that is useful in comparing the relative value of an SSD is to divide the price by the capacity to derive the cost per gigabyte. For example, if a 240GB SSD is $170, divide 170 by 240 to get a cost per gigabyte of $0.71. This metric helps you compare the best buy in terms of capacity in a given product line. In the majority of cases either the 240GB or 480GB models are the best value but with prices shifting all the time, other models may be a better value at any given time.
Are these the only SSDs to consider? Certainly not. These are, however, thoroughly validated SSDs from reputable companies that provide firmware updates right away if issues arise. I ran into some issues with a couple of older Crucial M4 SSDs and one of my Crucial M500 SSDs and a firmware update was already available to quickly solve the issue. No product is perfect but the speed and efficiency at which a company deals with the problem makes or breaks a product line. All of these products are of the highest quality.