Slow disk speed on Windows VM


New Member
Dec 17, 2015
I installed a fresh Proxmox VE and tested the speed of the disk:
root@pve:~# dd if=/dev/zero of=./test bs=1G count=1
1+0 records in
1+0 records out
1073741824 bytes (1.1 GB, 1.0 GiB) copied, 1.29498 s, 829 MB/s

Then installed VM(on the same drive) - Windows Server2012R2 + VirtIO drivers, and also tested the speed on different types of disks:
IDE - 12 MB/s Write, 24 MB/s Read
SATA - 58 MB/s Write, 128 MB/s Read
SCSI - 60 MB/s Write, 130 MB/s Read
VIRTIO Block - 57 MB/s Write, 127 MB/s Read

Why so slowly?
What am I doing wrong?


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