There could be many reasons for this ranging from network configured incorrectly to the source being the issue. However assuming that the data is located locally or on a fast server I would look at the following items. I have just built a new Dell server this week and this really helped (assuming HP has the same options)
1) DO NOT enable RTID - performance is hit hard if enabled
2) DO enable x2apic
3) DO enable I/O AT DMA
4) DO enable SR-IOV
5) DO NOT enable NMI button
6) Look at the raid set up and check that the element size is set to at least 256kb. the larger it is the faster the process but the more space is taken up by smaller files, ie a stripe size of 1mb will use 1mb of space for a 2k file. Larger stripes are recommended for databases however smaller strip sets impact performance.
If all this fails to improve performance then its not the setup of the RAID array causing your issue.
Good Luck
John