Hi,
I have been scratching my head for weeks, and I'm all out of ideas. I'm praying for some help.
I have a Broadcom MegaRAID 9560-16i (official Vmware support) with 2 Samsung PM9A3 NvME in RAID 1 mode.
ESXi 7.03c with latest drivers for the card, in passthrough mode also to Windows Server 2022 with latest drivers.
Then testing speed in ESXi with CrystalDiskMark, ATTO and real life database the READ performance is extremely slow with small random I/O.
It's equally slow in "Thick provisioned, eagerly zeroed" as in passthrough. I don't understand it at all. I have tried all kinds of stuff, powerprofiles, bioschanges, but nothing changes the outcome. The installed systemdrive Samsung 980 Pro is operating at the expected speed.
In desperation I have tried to install Windows Server 2022 (over the ESXI installation without any change to hardware or bios) and the speed is great, even in a Hyper-V visual machine without passthrough.
Top row is the results in baremetal Server 2022, and Hyper-V. Bottom row is results in ESXi with VMFS6 datastore and with passthrough of the raid controller.
I don't know what to try next. Is virtualized windows server handling the card differently, even when its in passthrough mode?
Any help will be greatly appreciated.