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 setting up all 8 drives in a RAID 0 and I'm getting 271.8mb/s transfer rates. Considering others on these forums using the exact same drives are getting 300-400mb/s using only 5 drives in a RAID 5, there's gotta be something wrong here.

 

[Blue Fox]

You don't mention write speeds at all and that's what matters. If you're getting 100mb/s+, that's saturating gigabit speeds, so you can't blame it on the controller card for any apparent slowdowns.

 

[odditory]

Considering others on these forums using the exact same drives are getting 300-400mb/s using only 5 drives in a RAID 5, there's gotta be something wrong here.

that statement assumes all hardware raid cards are created equal. they're not. you're using a generation of RoC that is six years old.

 

[coolrunnings]

Thanks for the feedback guys. Write speeds I was getting were around 50-60mb/s locally if memory serves me correctly but only about 20mb/s over the network (about 10% of gigabit according to task manager)...
odditory - I do get that I'm working with an old RAID card, but it was working faster with older drives and fewer of them. Is that expected performance on a card of that vintage? The person who quoted me speeds of 300-400 was an on Areca 1200 which uses the same Intel IOP333 chip and is of similar vintage if I'm not mistaken...