Performance on an LSI 8308ELP RAID Controller

[CoolRunnings]

I have been using an LSI MegaRAID 8308ELP card in my "server" box for the last 3 years or so with 6x 320gb Seagate 7200.10 drives in a RAID 5. It worked ok giving me speeds around 180mb/s to 200mb/s with peaks around 220mb/s or so. I needed more space so I picked up 8 HITACHI Deskstar 7K1000.C drives and put together a new RAID 5 with that. The performance, however, is TERRIBLE! I'm averaging 175mb/s at best on reads and backing up computers to it over gigabit LAN is unusably slow. What I am wondering is if you guys think it's just time for a new RAID card or if perhaps there is something wrong with the configuration... Here's a list of the other components in the system:

Asus P5N32-E SLI Turbo Motherboard
Core 2 Duo E6300 (the old 1.86ghz version)
2gb Corsair DDR2 800 RAM
650watt Corsair TX series Power Supply
80gb Seagate OS drive.

I tried running all 8 drives in a RAID 0 just to see if that made any difference in the speed and I'm peaking at 275mb/s. That just doesn't sound right considering that others using these same drives are getting 300-400mb/s in a RAID 5. Any help would be appreciated. Thanks!

 

[alaricljs]

Start by testing each disk individually. Maybe you have a dud?

 

[CoolRunnings]

Yeah I did do that. Each disk passed a full format and test before I put them in the RAID. Here's where it gets weird: they are doing almost 2-3 times better on Intel Matrix RAID now. I didn't realize how much better the ICH10R RAID was! I think I'm just going to switch to that and to heck with the RAID card.

 

[alaricljs]

Understand that Intel's RAID is mostly software running on your processor. If you're running a storage test it works great... If you're running something processor intensive AND disk intensive, then there's going to be a hit somewhere.

On the other hand, I run software raid on my server since it's a quad core box and that's a primary role for it. The other things running on it aren't that CPU intensive anyhow.

In RAID 5, the wider the array (more targets) the more complicated the checksum calculation is. Time for a heftier RAID card or switching to software RAID if it does the job for you.

 

[CoolRunnings]

Yeah I am going to switch to using Intel onboard RAID for these machines. These machines are file servers plain and simple. No heavy lifting. They simply serve files and back up my customers' drives. It should work great for what I need!