SSD speed NOT what it was expected

[kirelgt]

I have a adaptec Raid Card 6805 with the Zero Maintenance that comes with 4 Giga of Cache. On top of this this Raid card has 8 SSD Corsair in Raid 10, and each of this Corsair Force Series GT that each is rated at speed of 550 MB/s. When I run the following commands see the output I get.


proxmox1:~# hdparm -tT /dev/sdb1

/dev/sdb1:
Timing cached reads: 6054 MB in 2.00 seconds = 3028.54 MB/sec
Timing buffered disk reads: 872 MB in 3.00 seconds = 290.61 MB/sec
proxmox1:~# hdparm -tT /dev/sdb

/dev/sdb:
Timing cached reads: 6092 MB in 2.00 seconds = 3047.42 MB/sec
Timing buffered disk reads: 1678 MB in 3.00 seconds = 559.10 MB/sec
proxmox1:~# hdparm -tT /dev/sdc

This is slower that another normal raid I have of HDD. What could be happening.

Could it be that is formated wrong, what could be causing this problem.

 

[hisaltesse]

Having a similar issue as reported here.

1. Could you please post the results of the preperf command?
Pveperf

2. What is your server specs?

3. I just ordered the LSI 9265-8i to compare.

 

[tom]

I highly recommend to use only disks and SSD´s from the list of supported devices:

http://download.adaptec.com/pdfs/compatibility_report/arc-sas_cr_07-21-11_series6_lowport.pdf