In determining the RAID mode needed for a project I ran benchmarks using HDTune on a Dell PowerEdge 2850 with the PERC 4 controller on U320 SCSI 10K RPM disks. Hopefully this can help someone out in making a decision on what mode to use. Unfortunately I didn't benchmark any other RAID modes besides 50 and 10.
I will not go into details on how RAID works in all it's incarnations here, there are tons of documents elsewhere on the web.
If you cannot see the picture below I have typed out the details in a table. In short, RAID 10 offers superior performance in all areas except CPU usage, however with a 1% difference this is hardly a deciding factor. There is also a 146GB (1 disk) loss in a RAID10 configuration.
I will not go into details on how RAID works in all it's incarnations here, there are tons of documents elsewhere on the web.
If you cannot see the picture below I have typed out the details in a table. In short, RAID 10 offers superior performance in all areas except CPU usage, however with a 1% difference this is hardly a deciding factor. There is also a 146GB (1 disk) loss in a RAID10 configuration.
Ultra
320SCSI 10K RPM
|
RAID
50
|
RAID
10
|
Usable space
|
586 GB
|
440
GB
|
Transfer minimum
|
15.4 MB/sec
|
94.6
MB/sec
|
-Maximum
|
73.8 MB/sec
|
179.4
MB/sec
|
-Average
|
32.8 MB/sec
|
123.1
MB/sec
|
Access Time
|
8.7 ms
|
5.9
ms
|
Burst rate
|
256.3 MB/sec
|
291.2
MB/sec
|
CPU Usage
|
0.3%
|
1.3%
|
