raid - LSI MegaRaid 9260-8i low performance in comparison

I was given the task (aka dumped into my lap) to examine low Read/Write performance on a system running Server 2012 R2 /w HyperV role.

The system in question:

Lenovo RD340
LSI MegaRaid 9260-8i (no BBU)
-Drive Group 0 consisting of 2 SAS Drives, each 279.397 GB, RAID1
-Drive Group 1 consisting of 3 SAS drives, each 558.912 GB, RAID5

Virtual machines are stored on drive group 1.
VMs: Two domain controllers, a terminal server & an application server

It seems that read/write performance for drive group 1 is quite low. For example, when I try to export one of the VMs via HyperV Export onto the same drive (BYA: necessary for scripted exports), the max throughput is around 25~30 Megabytes/s. Seems low, especially in comparison to another system (Lenovo TD340 with LSI 9260-8i (with BBU)) where such an export nets around at least 150 MB/s and more.

Any idea what I should look out for to maximize performance?

Further settings for drive group 1:

• Strip size 64 KB


• Read Policy: No Read Ahead


• IO Policy: Direct IO



• Current write Policy: Write Through


• Default Write Policy: Writhe Through


• Current Access Policy: Read Write


• Default Access Policy: Read Write

The "control group" drive group on the RAID controller in the TD340:

• strip size 256 KB



• Read Policy: Always Read Ahead


• IO Policy: Direct IO


• Current Write Policy: Write Back


• Default Write Policy: Write Back with BBU


• Current Access Policy: Read Write


• Default Access Policy: Read Write

Thanks a lot!