3ware 9650SE/Giga-byte EP43-DS3 performance problems

[Techathy]

I've installed a 3ware 9650SE-8ML card in the PCI-E 4X slot of a EP43-DS3 motherboard & am having performance problems, like maximum throughput of 31.7MB/s where I'd be expecting to see at least 100MB/s from this configuration based on previous experience.

The performance issue also doesn't appear to be a limit on anything to do with the card or the disks as no matter what test I do I come up with a throughput of 31.5-31.7MB/s. This performance is consistent across Windows XP & Ubuntu linux. I've poked around in the bios but can't see anything that might help.

Does anyone have any suggestions on what is causing this low performance?

The system is:
Giga-byte GA-EP43-DS3
4GB DDR2-800
2.5GHz E5200 (Pentium Dual-Core)
Palit GeForce 210
Integral DOM SSD (UATA 16GB)
4x Samsung Spinpoint F4 1TB (software RAID5)
3ware 9650SE-8ML
8x Samsung Spinpoint F3 2TB (hardware RAID5)
Seasonic X-850 PSU

[Vimeous]

As you've eliminated the OS we're down at hardware/firmware.
The card is PCI-Express x4 v1.1 as is the slot.
Hmm....

Daft questions:
I assume the RAID5 array isn't rebuilding or degraded?
How are you getting the throughput figures?
Can the Southbridge cope with all those drives simultaniously?

[Techathy]

The RAID5 was in a fully initialised state with all drives operating properly - not that that initialising matters with 3ware cards as the initial build happens on a low priority & tends to result in a 10-15% reduction in throughput.

I first noticed the low performance on a standard 'rsync --progress -r /source /dest' command. However follow up was done with dd & iozone on linux & hdtach on windows. With the card being a hardware RAID controller it only 'sees' a single 13TB drive.

I also did a quick dd test with the software RAIDed drivers unplugged & there was no improvement.

[HxCxK]

I've installed a 3ware 9650SE-8ML card in the PCI-E 4X slot of a EP43-DS3 motherboard & am having performance problems, like maximum throughput of 31.7MB/s where I'd be expecting to see at least 100MB/s from this configuration based on previous experience.

The performance issue also doesn't appear to be a limit on anything to do with the card or the disks as no matter what test I do I come up with a throughput of 31.5-31.7MB/s. This performance is consistent across Windows XP & Ubuntu linux. I've poked around in the bios but can't see anything that might help.

Does anyone have any suggestions on what is causing this low performance?
...

I've also installed a 3ware 9650SE-4ML card in the PCI-E 4X slot and I was having performance problems like 10 - 27 MB/s. I later found out after extensive research and testing that if you keep your computer off, card has sat on a shelf for a long time or is new, that the battery may not be fully charged or charged to the threshold that it will utilize its write buffer. This will cause huge performance issues and will result in a very low Read/Write state. After leaving the computer powered on for 24 hours, Performance issues where fixed and now getting 139MB/s Write and 279MB/s Read!
Huge improvement from an average of 15MB/s Write and 32MB/s Read!

Hope that this helps someone!!!