On Sun, May 8, 2011 at 12:01 PM, guy keren <c...@actcom.co.il> wrote:
> On Sun, 2011-05-08 at 09:57 +0300, shimi wrote: > > what tends to get worse after the SSD becomes full is writes, not reads. > and combinations of reads and writes make things look worse (the writes > slow down the reads). > > You're of course correct. Hope this satisfies the issue: $ cat test.sh #!/bin/sh dd if=/dev/zero of=test123456.dat bs=1000000000 count=1 sync $ time ./test.sh 1+0 records in 1+0 records out 1000000000 bytes (1.0 GB) copied, 3.89247 s, 257 MB/s real 0m6.158s user 0m0.001s sys 0m1.738s (obviously dd itself has stuff in RAM. this is why I used time with sync after the dd. 1GB in 6.158 seconds is 162MB/s.... not too bad. still better than the Samsung F3 which is one of the fastest disks out there... same script on that 1TB drive takes 12.239s to complete the same task..) however, if you feel that the system is very fast after one year of use > - that's good enough for me. > > I do. And I don't think it's such a difference. Most writes are pretty small, and will not halt the system. I think most of the time the system is slow due to the heads busy with moving around the platter (seek), something that is almost completely eliminated in SSD - and *that's* why you have the performance boost. Correct, there are lousy SSDs that write very slowly, and then block I/O to the lengthy erase process, and will hang the app or the whole bus (depends on the controller, I guess?)... but I don't think the X25-E falls under that category :) do you have the ability to extract wear leveling information from your > SSD? it would be interesting to know whether the drive is being used in > a manner that will indeed comply with the life-time expentency it is > sold with (5 years?), or better, or worse. > > I don't know, how do you extract such information? The rated MTBF of my specific drive is 2 million hours. If I still know my math, that's some 228 years.... -- Shimi
_______________________________________________ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
