Did a test on two DL380 G5 controllers to check out the difference between having a battery or not on a P400 SAS RAID controller. The results are remarkable, to say the least.

Both machines are fairly identical when looking at disk configuration: both have a P400 SAS controller with an equal amount of storage, but srv1 has 512MB with battery, srv2 has 256MB without battery.

I ran a dd test of a file, and this is the output:

srv1:~# dd if=/dev/zero of=./dump.dump bs=1k count=81920008192000+0 records in8192000+0 records out8388608000 bytes (8.4 GB) copied, 48.282 seconds, 174 MB/s

srv2:~# dd if=/dev/zero of=./dump.dump bs=1k count=51200005120000+0 records in5120000+0 recor  ...