Low SSD Performance

Olaf Brenn

Well-Known Member
Jul 3, 2017
Hi there, we are running several Proxmox nodes with mainly HHD. One of them is using Samsung SSD in RAID 1 (Dell H700). The SSD performance within the VM is very poor. Data rate is not good but OK with 400 MB/s on read and 200 in write. Access time is always higher than 0,5 ms. I made a compare with a native install on another server with SSD. This gave me 500 MB/s and lower 0,1 ms access. When I use proxmox on the same test system I result in lower values.

I assume that this is not an issue with the RAID controller I use.
I use write back as cache and virtio driver and well as virtio SCSI with SSD support.
What can I do to get more performance out of the SSD's.
Is there any improvement on 6.1?


P.S. Others confirmed low performance on SSD
sorry, it is a EVO 850, we tested with WD green ssd as well, for sure those models are not enterprise level
Virtualization performance is never same as non-V. These are household models,so i wouldn't expect any bigger performance that it is now.
These are household models,so i wouldn't expect any bigger performance that it is now.

Yes, therefore I checked it too and I can back up his general performance loss/bad numbers in virtualization (with PVE):

PVE Host has 13-70us, VM has always over 400us (VirtIO SCSI). ZFS stripped mirror vdev on 6 Samsung Data Center Series SV843 MZ7WD960HMHP.


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