I'm having much trouble with I/O performance of HP DL360 server with two RAID controllers - P410i and P812, Windows Server 2008, 36 GiB RAM and 16 x Intel Xeon x5550. The server runs a bunch of tasks producing heavy sequential I/O, and after about 20-30 minutes of intensive work it looks like the tasks are stuck, not using CPU and with enough free memory (so this cannot be a bottleneck). The same tasks were running quite well on the older server (Windows Server 2003, 4 x Intel Xeon, 12 GiB RAM).
RAID cache is present, write-cache battery is installed. Cache is configured as 25% readahead/75% writeback. The swap file resides on the logical disk served by P410i and other logical disks are on P812.
Can someone tell me what can be the matter of this? Is this a hardware problem or misconfiguration?