Windows Server 2016 VM is very slow

[Marcio de Pier]

Hello dear friends, I need help.

I installed Proxmox 8.4.1 to convince a client to virtualize a server, but the virtualization was very slow. The server I installed was a Lenovo SR 650 V3, Intel(R) Xeon(R) Silver 4410Y CPU @ 2.0GHz with 128GB of 4800MHz DDR5 memory with 2TB NVME.

To get an idea of the slowness, I run a process in a Windows 11 VM on the same hardware as Windows Server 2016 in 20 seconds. On Server 2016, this same process takes more than 20 minutes. The process is to generate a report in an accounting system.

Can anyone help me solve this slowness in Windows Server?


Windows Server 2016 VM configuration:
/etc/pve/qemu-server/103.conf
#MacAddress%3A 7C%3AD3%3A0A%3AE8%3A8C%3AC9
#
#virtio1%3A local-zfs1%3Avm-110-disk-2,backup=0,cache=writeback,discard=on,iothread=1,size=500G
#virtio2%3A local-zfs1%3Avm-110-disk-3,backup=0,cache=writeback,discard=on,iothread=1,size=450G
#virtio3%3A local-zfs1%3Avm-110-disk-4,backup=0,cache=writeback,discard=on,iothread=1,size=300G
agent: 1,fstrim_cloned_disks=1
balloon: 16384
bios: ovmf
boot: order=virtio0
cores: 10
cpu: x86-64-v2-AES
efidisk0: local-zfs1:vm-103-disk-0,efitype=4m,pre-enrolled-keys=1,size=1M
machine: pc-i440fx-9.2+pve1,viommu=virtio
memory: 98304
meta: creation-qemu=9.2.0,ctime=1744397726
name: Win.Serv.2016
net0: e1000=7C3:0A:E8:8C:C9,bridge=vmbr0
numa: 1
onboot: 1
ostype: win10
scsihw: virtio-scsi-pci
smbios1: uuid=4ff2735c-705f-4465-baf2-84bacc114558
sockets: 2
tags: windows.server.2016
usb0: host=1-4
usb1: host=1-4
vga: virtio,memory=512
virtio0: local-zfs1:vm-103-disk-1,cache=writeback,discard=on,iothread=1,size=400G
virtio1: local-zfs1:vm-103-disk-2,cache=writeback,discard=on,iothread=1,size=450G
virtio2: local-zfs1:vm-103-disk-3,cache=writeback,discard=on,iothread=1,size=500G
virtio3: local-zfs1:vm-103-disk-4,cache=writeback,discard=on,iothread=1,size=300G
vmgenid: 286eee31-2e7e-4111-8452-da438aebca92


Windows 11 Configuration:
/etc/pve/qemu-server/190.conf
agent: 1
balloon: 2048
bios: ovmf
boot: order=virtio0
cores: 12
cpu: x86-64-v4
efidisk0: local-zfs1:vm-190-disk-0,efitype=4m,pre-enrolled-keys=1,size=1M
machine: pc-i440fx-9.2+pve1,viommu=virtio
memory: 8192
meta: creation-qemu=9.2.0,ctime=1744242943
name: Vim11-Acronis
net0: virtio=BC:24:11:9E:FE:C8,bridge=vmbr0,firewall=1
numa: 1
ostype: win11
scsihw: virtio-scsi-pci
smbios1: uuid=94c648fd-f643-4cde-9428-a091b6cfe1c7
sockets: 1
tags: win11.acronis
tpmstate0: local-zfs1:vm-190-disk-1,size=4M,version=v2.0
vga: virtio
virtio0: local-zfs1:vm-190-disk-2,cache=writeback,discard=on,iothread=1,size=50G
vmgenid: 466daf06-6e90-42ee-9712-b954334ec8fc