The drive
I want a fast solid-state drive (SSD), mid-range in capacity, that's also comparatively cheap. I also want to look like David Beckham. There's not much chance of me becoming the new Becks, but Crucial may well be able to help on the storage front.Crucial announced a 64GB model of its excellent RealSSD C300 SSD last week, tantalisingly priced at £118.66, bringing it with the reach of many enthusiasts looking for a super-speedy boot drive.
Knowing that high-performance 60GB SSDs command an outlay of £140, sometimes more, the question is how has Crucial managed to launch what appears to be a quality drive at a low-ish price.
| Crucial RealSSD C300 | 64GB | 128GB | 256GB |
|---|---|---|---|
| Interface | SATA
6Gb/s |
SATA 6Gb/s | SATA 6Gb/s |
| NAND type | MLC |
MLC | MLC |
| Read speed (up to) | 355MB/s | 355MB/s | 355MB/s |
| Write speed (up to) | 75MB/s |
140MB/s |
215MB/s |
| Random write 4K IOPS | 15,000 |
30,000 |
45,000 |
| Controller | Marvell | Marvell | Marvell |
| Buffer chip | Micron | Micron | Micron |
| Buffer size | 256MB | 256MB | 256MB |
| TRIM support | Yes | Yes | Yes |
| Retail price | £118 |
£315 |
£500+ |
| £ per GB | 1.84 |
2.46 |
1.95+ |
Keeping it in the family
A peek at the RealSSD C300 comparison table shows that the trio of SSDs are differentiated in terms of writing performance, with the 64GB model producing sustained writes at 75MB/s. We'll show you why this is the case a little further down the page, but it's worth noting that the 64GB drive ships with all the other goodies associated with the C300 line, including a SATA 6Gb/s interface, class-leading reading performance made possible by adherence to the ONFI 2.1 spec. and a 256MB buffer chip.
The 64GB SSD is at the top and the 256GB at the bottom. Both ship in a 2.5in form factor and are physically identical on the outside.
Open the casing and the drive uses a Marvell 88SS9174-BJP2 controller that connects to 16 NAND flash chips on the PCB - eight on each side. The chips are manufactured by IMFT, a collaboration between Intel and Micron, and are based on 34nm NAND.
Flip it over and the other eight chips come into view, along with a 256MB DDR3 buffer on the left-hand side.
But it's identical to a 256GB drive, right?
Hold on a second, you may be thinking, because the 256GB drive also uses this exact setup.
And you'd be correct in that assumption. The 64GB drive's PCB is at the top, identified by the later-production Marvell chip (week 10 of 2010).
The trio of Crucial RealSSDs all use 16 chips and the same Marvell controller. What this means is each drive's chips are composed of different capacities. For example, the range-topping 256GB's NAND flash chips are 16GB (128Gbit) in size, whereas the 64GB C300's are 4GB (32Gbit).
Making up the density for 16GB chips requires that Micron uses four NAND dies, while the 4GB chips, as provided in the 64GB drive, only use one NAND die. Put simply, it is the relationship between the number of NAND dies and the controller that dictates the degree of parallelism and, ultimately, writing performance. Appreciating how the RealSSD C300 line is setup from an architectural standpoint, this is why you see a reduction in writing speed as capacity is lowered.
Backed by a three-year warranty, the Crucial RealSSD C300 looks mighty potent for a £118 drive. Let's now put it to the test.
