I've been testing a HP DL380p with 16x SSDs in a RAID5 on the P420i controller with 2GB FBWC that is integrated on the board. Quite good performance, but not good enough. When I simulate the IO footprint I expect on ESXi, the Average Device Latency goes through the roof - 150 ms. What could cause this?
- Could the RAID controller be limiting the performance? If so, should I buy a second one?
- Would it be a good idea to swap to RAID 10 instead? For lower write penalty.