@memrob wrote:
I am sorry but this is wrong in this case. If you have two drives in a RAID TRIM isn’t working, therefore writing speed can decrease over the time. Furthermore in general writing to flash memory chips are getting slower the more often you write to it:
Wikipedia: “As a chip wears out, its erase/program operations slow down considerable.”
I am not sure if this also applies to the Toggle-NAND-Flash memory type SanDisk in the Extreme drives uses but I assume so.
I actually have evidence to back up my claims:
After running a sandisk extreme for 96 days of writing, there has been no degredation in write performance. In fact, it is a little bit faster now then it was when the drive started.
The sort of performance degredation Wiki talks about occurs at very much higher states of NAND wear, and can be sometimes seen if you abuse an older intel drive to death. More like 10-20 times the rated NAND life, and doesn’t occur before the drive reaches end of specification life. In any case, the sandforce controller will panic lock well before this effect comes into play. (As seen on several sandforce based drives already write endurance tested)
As for missing TRIM while in RAID performance degradtion, you can reduce this by not allocating all the drive space to the array, leaving more space for garbage collection, or simply secure erase them when they become too annoyingly slow. It has nothing to do with the NAND aging, which is what this thread is about.
