SSD Buyer's Guide

Know your Controller

There are dozens of SSDs on the market, from just as many drive partners. As with graphics cards though, the drive controller chips at the heart of the drives are designed by separate companies, with the companies we know as SSD manufacturers (Corsair, OCZ, Crucial and so on) buying the hardware in and adding it to their own PCBs and NAND flash memory. Frustratingly though, not every SSD on the market is upfront about what its drive controller is, making it difficult to be certain exactly what’s inside the box.

Indilinx Barefoot and Barefoot Eco

Used in: Corsair X-series, Corsair Nova Series, Crucial M225, G.Skill Falcon, G.Skill Falcon 2, OCZ Vertex, OCZ Agility, OCZ Solid 2, Patriot Torqx,

One of the first drive controllers to support the performance-maintaining TRIM command, drives based on Indilinx Barefoot, and its derivative the Barefoot Eco, typically have excellent sequential read and write performance. Read and write speeds are affected by the total capacity of the drive though, with smaller drives notably slower.

Barefoot Eco drives support cheaper 34nm, which can perform marginally faster than the 40nm of the plain Barefoot drives, as is the case with the Corsair Nova and G.Skill Falcon 2. Random read performance is good at around 35MB/sec, with random write speeds of around 12-15MB/sec.

TRIM utilisation is excellent in Windows 7, with the mature reliable firmware. While the OCZ Solid 2 uses the Indilinx Barefoot controller, it’s been modified in some way to significantly reduce speeds, with sequential speeds dropped to around 220MB/sec read and 130MB/sec write, with a reduction in random performance to match. Also be wary of drives based on the Indilinx’s Amigos chip like the OCZ Oynx, which deliver even further reduced performance for a nominal discount.

Verdict: Indilinx is a great choice for use as boot drive or a high-performance storage drive for your games and demanding applications. The controller is starting to show its age after 18 months on the market though, with SandForce and the Marvell-powered Crucial C300 series providing strong competition.

Intel

Used in: Intel X25-M (gen 1), X25-M (gen 2), Intel X25-V ,Intel X25-E, Kingston SSDNOW M-Series, Kingston SSDNOW V series 40GB (discontinued)

Intel’s drive controller was the first to hit superb random write speeds, and at a time when JMicron’s JMF602-based drives were stuttering up a storm. The first generation X25-M drives (part numbers SSDSA2MH080G1GN and SSDSA2MH160G1) were sadly dropped by Intel, and haven’t received a TRIM compatible firmware update, unlike the 34nm-NAND-based generation 2 drives.

Performance of Intel drives is linked directly to capacity, with the 160GB model delivering up to 250MB/sec sequential read speed while the 40GB drive manages 'just' 180MB/sec. Sequential write speeds aren’t so good though, and even the 160GB model will only manage 100MB/sec, with the 40GB model managing roughly 45MB/sec. Random read and write performance make up for it though, as both are over 50MB/sec. Intel-based Kingston drives with part numbers that end S2 rather than S2B are to be avoided, as these are the older models that lack the TRIM-enabled firmware.

Verdict: While sequential read/write performance is lacking, the Intel controller delivers on every other front, making it a great choice. We’re unconvinced of the need for random write speeds of more than 10MB/sec though, and as Indilinx drives offer faster sequential writes we’d opt for an Indilinx if given the choice.