Strange vm vdisk performance.

[frodr]

I found, what looks to me, like some strange disk performance on Windows and Windows Pro vm`s. 

 

1. reading:

Windows 10 Home with 4 cores on CPU 1, vdisk on Cache Raid10 (4 x nvme ssd on Acer Hyper M.2 in PCIe (cpu1).

 

2. reading:

Windows Pro 10 with 8 cores on CPU 2, vdisk on Cache Raid10 (4 x nvme ssd on Acer Hyper M.2 in PCIe (cpu1).

 

3. reading: 

Windows Pro 10 with 8 cores on CPU 2, passthrough nvme ssd on mainboard socket. 

 

I don't have any performance issues, but is curious about this performance. Are they strange?

 

 

Cheers,

 

 

Supermicro X11DAI-N, version 1.02 | AMI 3.1 | dual Xeon Silver 4116 | 64 MB RAM | 4 x Corsair Force MP510 (960GB) NvME ssd on Asus Hyper M.2x16 V2 l Unraid 6.72 l Quadro RTX4000 for Plex docker l RTX 2080 for Win kvm l Samsung 970 Pro as second ssd for Win Pro kvm l Asmedia PCIe USB card.

Edited November 16, 2019 by frodr

[bastl]

@frodr Do the tests with bigger than 1G files. Keep in mind that NVME drives tend to throttle on heavy workloads if they get to hot. If they don't cool down after the tests you will see differences in performance between the tests.

 

But more important on default the vdisks are set up in a way, where caching is enabled.

<driver name='qemu' type='qcow2' cache='writeback'/>

Set the cache to "none" in the xml to prevent Unraid caching during the benchmarks to see the real numbers.