Originally Posted by Forceman
It's not solely on the NAND being used. The NAND does matter between different models, but in most cases the smaller drive of the same model will be slower. The 64GB Samsung 830 is rated at 520/160 for example, while the 128Gb model is rated at 520/320, and the 256GB and 512GB are 520/400. Same controller, same NAND, in all those cases, the difference is the number of parallel channels the drive can use.
We have channels to deal with our NAND limitations. This allows the controller to communicate in sync with multiple NAND chips. Each chip is only rated for a specific read and write speed. To break beyond this barrier we have to use what is called channels. In laymans terms, it works very similar to raid solutions today. To go beyond the capabilities of a single NAND chip. Instead of utilizing a single chip that is capable of say 100MB/s read and write. We can utilize three chips across three channels to give us 300 MB/s read and writes.
Originally Posted by Forceman
It's faster, but not really in a noticeable way. The random access time is already so good on a single SSD that RAID doesn't really help as much as it would for spinning drives, and there's a limit to how much benefit the increased sequential performance will give you. Sure you can load that 100MB file into memory at 900 MB/s, but is that really going to be that much faster than at 500 MB/s? What's a tenth of a second among friends, after all? Plus you have an increased data loss risk (small though it may be), and unless you have a Z77 motherboard you lose TRIM. So I'd just get the larger single drive. Plenty of guys have RAID SSDs though, so it is a viable option.
You wouldn't strip drives for access speeds, when you strip drives you're essentially combining the data rate capabilities of them. The way stripping works is it "strips" a file of its bytes and writes out the file byte by byte across the raid array. This breaks up the workload among several drives multiplying the raw transfer speed. The only downside to a stripping array is it combines the latency of the drives. Tho with SSD's having 0.1ms seek times, its hard to say you would even notice a difference. If you are doing high I/O workloads all of the time. Then a stripping array of two 256GB 830's would double your effective transfer speeds to just shy under 1000 MB/s read 800 MB/s write. Tho I wouldn't recommend a normal user to take it to that extreme. If you're looking for a "faster" drive when already owning a SSD, the only way up is in data rate. A single 830 will offer almost double in both reads and writes in comparison to his old drive. Plus the 830 is the most reliable drive on the market currently, that is at a acceptable price point. I would get a 256GB 830 and be done with it, if he wants faster later. He can always buy a second to put in a stripping array. Tho like said, you would have to be doing high I/O workloads all the time
to benefit from one.Edited by Warmonger - 11/10/12 at 6:12pm