I originally came across the issue of slow storage performance with the native vmw_ahci driver that comes bundled with ESXi 6.5 just as I was first playing with my SuperMicro SYS-5028D-TN4T in my homelab. After publishing a couple of posts about the workaround shortly afterwards the issue become quiet prevalent in the community and the post continues to get decent traffic, meaning that the issues impacted quiet a few people out there.
The good news is that with the release of vSphere 6.5 Update 1 there is a fix for the problem in the form of updated drivers for the AHCI module. William Lam has been quick to blog about the fix and if you had previously disabled the driver you will need to re-enable it.
[root@LAB-ESXI-01:~] esxcli system module set --enabled=true --module="vmw_ahci"
[root@LAB-ESXI-01:~] esxcli system module list | more
Name Is Loaded Is Enabled
----------------------------- --------- ----------
vmkernel true true
chardevs true true
user true true
vmkapi_v2_1_0_0_vmkernel_shim true true
vmkusb true true
igbn true true
vmw_ahci true true
iscsi_trans true true
iscsi_trans_compat_shim true true
vmkapi_v2_2_0_0_iscsiInc_shim true true
This VMwareKB covers the specific patch as listed in the release notes:
No confirmation as of yet if it actually does the trick, but the release notes look promising as the assumption is that it will resolve the issues so that homelabbers and people using the driver in production systems can rest easy.