ESXi 6.5 B120i (hpvsa) HP Microserver Gen8 Low performance

I performed a clean install of ESXi 6.5 on HP Microserver Gen8 with provided HP image (VMware-ESXi-6.5.0-OS-Release-4564106-HPE-650.9.6.0.28-Nov2016). I have the datastore on a Raid 1 logical disk in b120i.

When I access to and from datastores over network through vSphere Client (6.0.0) is very slow ~20 Mbps. In virtual machines the performance has dropped significantly and the overall file copy is much slower.

I tried to install scsi-hpvsa-5.5.0-88 which gives good performance on ESXi 6.0 but ESXI 6.5 stopped recognizing my datastores.

Finally i Install again ESXI 6.0 with scsi-hpvsa-5.5.0-88 to get best stable enviroment.

What can be done to be able to have the advantages of ESXI 6.5 with a good performance on HP Microserver Gen8 and B120i?

Thanks