ML370 G6 - Speed reference raid 5

[Dennis_K]

Hi,

we've got some performanceproblems with out ML 370 G6 Server.

The configuration is:

SmartArray P410i
4x 450 GB SAS 15K HDDs as a RAID 5 (1,2TB) - Array Accelerator activated

A performance test with HD Tune gives the following data:

Minimum Transfer Rate: 63,7 MB/sec
Maximum Transfer Rate: 138,3 MB/sec
Average Transfer Rate: 122,7 MB/sec

Access Time: 5.4 ms
Burst Rate: 431,4 MB/sec

Can anybody give me some referencedata.
Are these data ok?

[Alex Geroulaitis (ITRC)]

Sounds valid even though each one of those 15K drives clock at over 120MB/s individually.

I get similar results on a DL380 G5, RAID 6 (6 7200rpm SFF SATA drives, P400 controller 512K), and various workstations with on-board RAID chips.

RAID levels 5 and 6 have quite a bit of an overhead on writes and much faster performance on reads; on top of it, the RAID controller's CPU can have quite an effect on write performance as it calculates parity on the fly; P400 and P410 aren't known for their speeds. To increase performance, you may want to use a faster RAID controller. Having more drives in a RAID set may also help - depending on the controller.

[andy-x]

Sorry Alex. What is speed for raid5 with 3 hard disk 146Gb 10K and controller p410i-256?
I have find max write speed 26Mb/s for large file (500Mb). Is Ok this speed?

[Alex Geroulaitis (ITRC)]

"What is speed for raid5 with 3 hard disk 146Gb 10K and controller p410i-256?"

Theoretically - 20-50MB/s depending on OS and associated hardware.

"I have find max write speed 26Mb/s for large file (500Mb). Is Ok this speed?"

Yes although I wouldn't call 500MB a "large file". Try a file that's at least 5 times your server's RAM amount. E.g. if your server has 12GB RAM in it, use a 60GB files (or a 60GB sequence of files) to measure the throughput. Otherwise memory caching may affect your numbers and make them unreliable.

To increase the write speed to 40-60MB/s, increase the number of drives to 4-5.

To increase the write speed to over 100MB/s, use a different RAID controller (Areca, Hipoint).