RAID10 Question

[Cyberbeing]

I just bought a 3ware 9650SE and I am debating how to setup my drives.

The drives in question are the following:
Two 500GB Hitachi 7K500
Two 500GB WD RE2 5000YS

Now my question is what will performance be like putting these 2 sets of different drives in a RAID10 array versus just making two RAID1 arrays? In RAID 10, would it be best to have the same drives or the opposite drives in each mirror set considering that the two mirrored arrays are then striped together?

Do you think I would get better performance out of a RAID5 array instead?

 

[axan]

i don't think you quite grasp what the different levels of raid do. When you say performance do you mean read or write? or both? cuz raid 1 and 5 suck ass for write (raid 5 way more then 1). raid 5 will win on read and raid 10 will have best overall read and write. As for how to setup raid 10 go with raid 1 of wd drives with raid 1 of hitachi drives then stripe them.

 

[Cyberbeing]

Yes, I'm not too familiar with the different RAID levels and their performance impacts. The only RAID level I have even dealt with is RAID0 and that doesn't help me much.

What I was trying to ask is would either RAID10 or RAID5 take a major performance impact (either reads or writes) from mismatched drives enough to make you not want to use it?

Overall, my order of importance would probably be sequential writes (over single disk performance if possible), random reads, sequential reads, and lastly random writes.

Also, I just found this 3ware PDF (http://tinyurl.com/29ndz4) showing 4 drive benchmarks in RAID0, RAID5, and RAID10 on an older 3ware card and it looks like RAID5 has sequential reads relativity close to RAID0 and not far below the sequential writes of RAID10. Is that normal?

 

[axan]

there won't be much if any performance hit because of the mismatch drives. As far as raid 5 coming close to write performance of raid 10 it's only possible if you have writeback cache enabled (raid controller stores data in its ram first and writes to disks later) but most controllers will only allow you to enable wb cache if you have battery backup for the card. In your case i would go with raid 10 you will get good write and read performance.