Very poor RAID 5 performance, help!

PiKe

PiKe

PiKe

Caporegime
Joined
18 Oct 2002
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Lake District
Just build a RAID 5 server with 4 drives and 1 hot spare.

On doing the hdtach benchmark its giving almost 300MB/s burst but only 60/70MB/s sequential read, what's going on? It should be more like 240MB/s.

Can anyone help? :(
 
The onboard ICH8R.

hdtach.png


This is a benchmark from the same system except the hard drives are 10,000rpm and the CPU is quicker:

hdtach-ich8-raid5-big.gif
 
The raptors were in RAID5 aswell, but I'm sorry, 2500rpm isnt going to make the massive difference seen there, softraid or not.
 
In mine, C2D 1.80ghz, in the other one, Some E series chip with 4mb cache.

During testing the CPU utilisation in HDtach is only 3% as you can see.
 
Tried ATTO benchmark, transfer size 1024 length 8mb and got 635MB/s read and 25MB/s write?
 
That was one avenue I explored but no, it wasn't that.

I went looking for the latest Intel drivers but that made no difference, then I poked around the intel storage manager and found that Volume-Write Back Cache wasn't enabled, enabled it and ran the test again and the results are what you can see above :)
 
From someone on this forum:

Burst speeds on Intel boards tend to be mad due to the burst coming from the cache on the ICH chip, therefore, the max bandwidth is that of the ICH to MCH interconnect.
Click to expand...
 
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