RAID Controller on IBM hosts System x3850 x5 7145 AC1 is the cause of high latencies

If customer is using IBM System x3850 x5 7145 AC1 VMware hosts, then despite high cache hit ratio with VirtuCache, performance improvement is not seen versus a slow SAN based appliance, because driver latencies (both read and write) in the RAID controller are high. This is a problem with the firmware on the RAID controller that IBM needs to update. The other option is to use a PCIe Flash card since this IBM host has 7 PCIe slots.