I've just update my home server from vSphere Hypervisor 6.0 to 6.5 and facing very low disk performance issue.
I've attached 2 SSD to my home server (NO RAID), one is Sandisk X210 512GB, which has this issue. Another one is a legacy Samsung 830 128GB which is normal and quite fast.
Below is the figure from esxtop when I am uploading one big file to the data store on Sandisk X210 from vSphere web client, it is rather slow.....
Here is per device view in the above action...
I have no idea how to do further investigation on this...anyone help?