With prices plummeting further every week, it's a great time to invest in solid-state storage. Although the market seems flooded with SSD options, there are really only a few relevant controllers used today, and they come from SandForce, Marvell and Samsung.

The second-generation SandForce SF-2281 is probably best known for its use in the OCZ Vertex 3 and offers respectable performance, but it's not without shortcomings. SandForce isn't exactly synonymous with reliability, with many SF-2281 drives having stability issues early on. Additionally, Intel recently discovered that the controller can't handle AES-256 encryption -- an issue that runs deep enough that it can't be solved with a firmware update.

For its latest enthusiast drive, the Vertex 4, OCZ claimed to have used its own in-house Indilinx Everest 2 controller, but this turned out to be a rebadged Marvell chip -- presumably the 88SS91874, though this is yet unconfirmed. If that's true, it shouldn't necessarily be cause for concern as the 88SS91874 has proven to be fast and reliable in drives such as the Crucial m4, which we've tested extensively and still recommend as a viable solution.

Outside the realm of SandForce and Marvell, you have Samsung, whose 470 and 830 Series have been manufactured entirely in-house, including the controller, memory and cache. The latter drive launched last September with Samsung's MCX controller (S4LJ204X01-Y040) and has remained a solid option in terms of speed, reliability and affordability -- especially with the recent price drops, which have placed the 256GB 830 at only $0.76 per gigabyte, a minor and well justified $0.06 premium over the Vertex 3.

While the 830 Series and many of its year-old peers may still be attractive, Samsung is ready to move on to bigger and better things. As such, the company has announced a fresh lineup this week, including a new flagship offering, the SSD 840 Pro, which is said to refine the 830 Series' firmware with faster random and sustained performance as well as improved reliability.

Alongside its new drives, Samsung is also releasing its Magician 4.0 software that provides SSD 840 Pro users with an interesting feature called user-configurable over-provisioning, which reserves 7 to 24% of the SSD's storage for functions such as creating pre-erased, ready-to-use memory blocks. This lets users choose what's most important to them: speed or capacity.

Since most SSD competitors use the same rehashed components, Samsung has been in a unique position to shake things up over the last few years, and it's done a fine job. We had nearly no expectations for 2010's 470 Series, but we were pleasantly surprised when it dominated our performance charts. Last year's 830 Series gave a repeat performance, so we can only hope the same of the 840 Pro.

Samsung SSD 840 Pro

Samsung will offer four versions of the 840 Pro including 64GB, 128GB, 256GB and 512GB models. The 256GB and 512GB modules claim a 540MB/s read and 450MB/s write performance, which is slightly faster than the previous-generation 830 Series' rates of 520MB/s and 400MB/s.

The new drive has been fitted with Samsung's latest MDX controller (S4LN021X01-8030), a triple-core ARM-based chip that supports SATA 6Gb/s and can be paired with the latest 20nm NAND flash memory.

According to Samsung, the 840 Pro's MDX controller provides superior multi-tasking results under heavy I/O loads and provide steadier performance on more tasks. Based on an ARM Cortex R4 (300MHz) processor, the three cores can execute multiple instructions at once, allowing, for example, one to be used for reading data, one for writing data and another for optimization.

Our 512GB review unit carried Samsung NAND flash memory labeled K9PHGY8U7A-CCK0, which is fabricated using 2y-nm tech. There are eight chips with each IC having a massive 64GB density. The drive weighs 62.5 grams and measures 100 x 69.85 x 7mm, which is thin enough to fit in most modern ultraportable systems.

Although all SSDs are power conservative, Samsung boasts that its drives are particularly so. At idle Samsung claims, all four models use 0.042 watts and a mere 0.068 watts when active, whereas most other drives use 2 to 4 watts of power when active.

Samsung claims a MTBF of 1.5 million hours and a 1500G shock resistance -- typical estimates for SSDs -- and the 840 Pro is backed by a limited five-year warranty.