(help) Awful performance on Windows 2022 via Proxmox

DeadlyChemist · March 2025

finally managed to migrate my server to proxmox as seen here https://lowendtalk.com/discussion/202212/need-help-move-windows-vps-to-proxmox#latest

anyways, same hardware but now proxmox is in the way, i expect slightly worse performance....
but it's terrible
i just booted windows and cpu usage is like 50%

will send configs (windows vm) and proxmox so you can see hardware/allocation later when im home
opening browser takes forever, doing anthing takes forever
feels like intel pentium

please let me know what i could adjust/send here

nullnothere · March 2025

I'm not sure if you have enabled full cpu pass through but try disabling it - Windows seems to automagically enable spectre/meltdown (etc.) mitigations which can result in poor performance. Of course it's just a hunch that may help you.

lowenduser1 · March 2025

first guess would be vm config not properly set for windows os. it also could be simply windows update or anti malware due to rebooting. check resource monitor and the vm config. the virtio drivers will perform better but require the the drivers to be installed in the guest first. it matters for disk mostly but could result in cpu

DeadlyChemist · March 2025

vm config
root@hbrr-proxmox:/etc/pve/qemu-server# ls
100000.conf
root@hbrr-proxmox:/etc/pve/qemu-server# cat 100000.conf
boot: order=ide2;scsi0
cores: 7
cpu: qemu64
ide2: none,media=cdrom
memory: 18048
meta: creation-qemu=8.1.5,ctime=1740547915
name: Windows-Server-22
net0: virtio=BC:24:11:BD:A4:A8,bridge=vmbr1,firewall=1
numa: 0
ostype: l26
scsi0: local-lvm:vm-100000-disk-0,iothread=1,size=230G
scsihw: virtio-scsi-single
smbios1: uuid=b0f3b2ee-707f-4c03-a7a9-db9dd04fc83d
sockets: 1
vmgenid: baecca52-76db-4da2-a924-1e558469b6c5

[PENDING]
agent: 1

@nullnothere said:
I'm not sure if you have enabled full cpu pass through but try disabling it - Windows seems to automagically enable spectre/meltdown (etc.) mitigations which can result in poor performance. Of course it's just a hunch that may help you.

@lowenduser1 said:
first guess would be vm config not properly set for windows os. it also could be simply windows update or anti malware due to rebooting. check resource monitor and the vm config. the virtio drivers will perform better but require the the drivers to be installed in the guest first. it matters for disk mostly but could result in cpu

i tried the CPU type as HOST but then it does not want to boot.....
idk why
ideas?

lowenduser1 · March 2025

@DeadlyChemist said:
vm config
root@hbrr-proxmox:/etc/pve/qemu-server# ls
100000.conf
root@hbrr-proxmox:/etc/pve/qemu-server# cat 100000.conf
boot: order=ide2;scsi0
cores: 7
cpu: qemu64
ide2: none,media=cdrom
memory: 18048
meta: creation-qemu=8.1.5,ctime=1740547915
name: Windows-Server-22
net0: virtio=BC:24:11:BD:A4:A8,bridge=vmbr1,firewall=1
numa: 0
ostype: l26
scsi0: local-lvm:vm-100000-disk-0,iothread=1,size=230G
scsihw: virtio-scsi-single
smbios1: uuid=b0f3b2ee-707f-4c03-a7a9-db9dd04fc83d
sockets: 1
vmgenid: baecca52-76db-4da2-a924-1e558469b6c5

[PENDING]
agent: 1

@nullnothere said:
I'm not sure if you have enabled full cpu pass through but try disabling it - Windows seems to automagically enable spectre/meltdown (etc.) mitigations which can result in poor performance. Of course it's just a hunch that may help you.

@lowenduser1 said:
first guess would be vm config not properly set for windows os. it also could be simply windows update or anti malware due to rebooting. check resource monitor and the vm config. the virtio drivers will perform better but require the the drivers to be installed in the guest first. it matters for disk mostly but could result in cpu

i tried the CPU type as HOST but then it does not want to boot.....
idk why
ideas?

https://pve.proxmox.com/wiki/Windows_2022_guest_best_practices rtfm

double click the start task in the bottom bar. see why it doesnt boot. is VT enabled in BIOS?

DeadlyChemist · March 2025

@lowenduser1 said: https://pve.proxmox.com/wiki/Windows_2022_guest_best_practices rtfm

double click the start task in the bottom bar. see why it doesnt boot. is VT enabled in BIOS?

will check the link, tho i still require help, you guys know more

VT should be enabled and the VT-passthru thing...im on a VPS, not bare metal

it does start, just after entering bios password, it shows windows symbol (no loading thing!) and after 10mins or so it restarts, can try again later today

DeadlyChemist · March 2025

implemented some tipps from the link

root@hbrr-proxmox:/etc/pve/qemu-server# cat 100000.conf 
agent: 1
boot: order=ide2;scsi0
cores: 7
cpu: qemu64
ide2: none,media=cdrom
machine: pc-i440fx-9.0
memory: 18048
meta: creation-qemu=8.1.5,ctime=1740547915
name: Windows-Server-22
net0: virtio=BC:24:11:BD:A4:A8,bridge=vmbr1,firewall=1
numa: 0
ostype: win11
scsi0: local-lvm:vm-100000-disk-0,iothread=1,size=230G
scsihw: virtio-scsi-single
smbios1: uuid=b0f3b2ee-707f-4c03-a7a9-db9dd04fc83d
sockets: 1
vmgenid: baecca52-76db-4da2-a924-1e558469b6c5

performance still awful

nullnothere · March 2025

@DeadlyChemist said: performance still awful

Can you peek into task manager (within Windows) and see WHAT is hogging CPU (or IO)?

Hopefully you can figure out why it doesn't boot when you do pass through the CPU and fix it to boot - then see if that helps.

DeadlyChemist · March 2025

@nullnothere said:

@DeadlyChemist said: performance still awful

Can you peek into task manager (within Windows) and see WHAT is hogging CPU (or IO)?

Hopefully you can figure out why it doesn't boot when you do pass through the CPU and fix it to boot - then see if that helps.

im desperate for a fix, and frustrated

Calypso · March 2025

@DeadlyChemist said:
VT should be enabled and the VT-passthru thing...im on a VPS, not bare metal

Do I understand correctly that you're using ProxMox on an already virtualized environment?

If so (I wouldn't do it, especially with Windows, but OK), what are the specs of the VPS you're running on? Dedicated specs or shared?

DeadlyChemist · March 2025

@Calypso said: Do I understand correctly that you're using ProxMox on an already virtualized environment?

yupp
so proxmox is virtualised and windows would be nested

shared
ryzen 9 5950X (8 cores) proxmox says 8 sockets
20gb ram

nullnothere · March 2025

@DeadlyChemist said: im desperate for a fix, and frustrated

So is it LET on Firefox - how ironic!

It may help to shutdown Firefox and just let the VM (i.e. Windows) to finish it's bookkeeping (esp. if you just did an upgrade etc.) and then after things quieten down, see if things are back to the usual.

Don't have anything concrete right now... but let's see if patience pays to restore normalcy.

DeadlyChemist · March 2025

@nullnothere said: So is it LET on Firefox - how ironic!

It may help to shutdown Firefox and just let the VM (i.e. Windows) to finish it's bookkeeping (esp. if you just did an upgrade etc.) and then after things quieten down, see if things are back to the usual.

Don't have anything concrete right now... but let's see if patience pays to restore normalcy.

already been an half an hour or so
yeah, i'll see when i come home in 2h if it's better.....
but without proxmox i had WAY better performance

still need tipps

will try to get type as HOST, but idk why it does not boot

host_c · March 2025

@lowenduser1 said: scsi0: local-lvm:vm-100000-disk-0,iothread=1,size=230G

Is this Proxmox in Proxmox or Proxmox on bare metal?

If Bare Metal:

On the Drive:

drop IOTHREAD.
Enable SSD Emulation

I would definitely drop LVM. I would use a directory mount with a file system ( preferably xfs not ext4 ) and a raw image file for the VPS

If not, disregard the above.

Eitehr the case, on CPU:

CPU: HOST
enable 1 GB Pages - mandatory
enable AES - mandatory

Calypso · March 2025

You definitely need nested virtualization to have a chance of a usable KVM. According to ProxMox themselves (https://pve.proxmox.com/wiki/Nested_Virtualization):

VM/CT performance without hardware-assisted virtualization extensions

if you can't setup hardware-assisted virtualization extensions for the guest, performance is far from optimal! Use only to practice or test!

VM (KVM) will be really slow, nearly unusable (you can expect 10x slower or more), since (as said above) they're running without KVM hardware virtualization

DeadlyChemist · March 2025

@host_c said: Is this Proxmox in Proxmox or Proxmox on bare metal?

some hypervisor (hostbrr) running my proxmox and my windows 2022

CPU: HOST - not yet enabled
enable 1 GB Pages - mandatory - enabled (gotta restart)
enable AES - mandatory - enabled (gotta restart)

@Calypso said:
You definitely need nested virtualization to have a chance of a usable KVM. According to ProxMox themselves (https://pve.proxmox.com/wiki/Nested_Virtualization):

VM/CT performance without hardware-assisted virtualization extensions

if you can't setup hardware-assisted virtualization extensions for the guest, performance is far from optimal! Use only to practice or test!

VM (KVM) will be really slow, nearly unusable (you can expect 10x slower or more), since (as said above) they're running without KVM hardware virtualization

i used WSL on windows 2022 before so i assume nester virtualisation is enabled, i did get good performance...
i know he had it enabled

lowenduser1 · March 2025

according to your task manager its actually updating or malware scanning. figure out with your host why passthrough doesnt boot windows. qemu64 is slower. nested virt does suffer more but its enabled otherwise you wouldnt be able to boot. perhaps virtio drivers help here. you will want to set the disk in proxmox ask described in my prev link. but for starters pass it less cores and memory to ensure your not overcommitting

DeadlyChemist · March 2025

@lowenduser1 said:
according to your task manager its actually updating or malware scanning. figure out with your host why passthrough doesnt boot windows. qemu64 is slower. nested virt does suffer more but its enabled otherwise you wouldnt be able to boot. perhaps virtio drivers help here. you will want to set the disk in proxmox ask described in my prev link. but for starters pass it less cores and memory to ensure your not overcommitting

i have windows drivers installed
im definetly not overcomitting
6-7/8 cores is fair and 15-17gb/20 is fair too

thats how my other servers run, without issues (they are more loaded actually)

did more testing:
works:
cpu: qemu64,flags=+pdpe1gb;+aes

does not work:
cpu: host,flags=+pdpe1gb;+aes
cpu: host

+pdpe1gb;+aes defiently speeds up

now trying to get host working...

DeadlyChemist · March 2025

@lowenduser1 said: figure out with your host why passthrough doesnt boot windows
@host_c said: CPU: HOST

ideas? it's stuck like this for a while....
so i turned it off before i get in trouble

host_c · March 2025

Emulation is Q35 or 440fx??

Try q35, but sincerely that is interesting to see that it does not boot

DeadlyChemist · March 2025

@host_c said: Emulation is Q35 or 440fx??

Try q35, but sincerely that is interesting to see that it does not boot

will try, right now i have set cpu to 6 cores and like 3, so it maxes out 50%

the laoding symbol on windows 2022 is spinning

fuck knows why it does not boot

bitlocker (i always have to enter a key which is fine)? licenses?

will give it an hour longer and then will try your q35

you are a great help, thanks, i hope we can solve it (ok i beg at this point)

Patriarch · March 2025

@DeadlyChemist
So, the proxmox run on a Shared VPS
Can you share yabs from the VPS itself?

w3e4r5 · March 2025

enable BIOS VT-x VT-d, q35 platform, CPU at x86-v2-AES,if host harddrive is not SSD will very slow.

DeadlyChemist · March 2025

@DeadlyChemist said: will give it an hour longer and then will try your q35

so, it loaded? and i ended up in a black screen with high cpu usage
i can move and see my cursor, but it's black screen and RDP does not work

tried your settings

@host_c said: Try q35, but sincerely that is interesting to see that it does not boot

does not boot but cpu usage seems lower (weird, but not muvh, could be margin of error)

@Patriarch said: Can you share yabs from the VPS itself?

yes partial (check below)

@w3e4r5 said: enable BIOS VT-x VT-d, q35 platform, CPU at x86-v2-AES,if host harddrive is not SSD will very slow.

i dont have access to bios as it's shared
x86-v2-AES is slow
it's all SSD with good speed

here is some info:

root@hbrr-proxmox:~# lscpu
Architecture:             x86_64
  CPU op-mode(s):         32-bit, 64-bit
  Address sizes:          40 bits physical, 48 bits virtual
  Byte Order:             Little Endian
CPU(s):                   8
  On-line CPU(s) list:    0-7
Vendor ID:                AuthenticAMD
  BIOS Vendor ID:         QEMU
  Model name:             AMD Ryzen 9 5950X 16-Core Processor
    BIOS Model name:      pc-i440fx-5.2  CPU @ 2.0GHz
    BIOS CPU family:      1
    CPU family:           25
    Model:                33
    Thread(s) per core:   1
    Core(s) per socket:   1
    Socket(s):            8
    Stepping:             2
    BogoMIPS:             6787.24
    Flags:                fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 syscall nx mmxext fxsr_opt pdp
                          e1gb rdtscp lm rep_good nopl cpuid extd_apicid tsc_known_freq pni pclmulqdq ssse3 fma cx16 sse4_1 sse4_2 x2apic movbe popcnt tsc
                          _deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm cmp_legacy svm cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw 
                          perfctr_core ssbd ibrs ibpb stibp vmmcall fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid rdseed adx smap clflushopt clwb s
                          ha_ni xsaveopt xsavec xgetbv1 xsaves clzero xsaveerptr wbnoinvd arat npt nrip_save umip pku ospke vaes vpclmulqdq rdpid fsrm arc
                          h_capabilities
Virtualization features:  
  Virtualization:         AMD-V
  Hypervisor vendor:      KVM
  Virtualization type:    full
Caches (sum of all):      
  L1d:                    256 KiB (8 instances)
  L1i:                    256 KiB (8 instances)
  L2:                     4 MiB (8 instances)
  L3:                     512 MiB (8 instances)
NUMA:                     
  NUMA node(s):           1
  NUMA node0 CPU(s):      0-7
Vulnerabilities:          
  Gather data sampling:   Not affected
  Itlb multihit:          Not affected
  L1tf:                   Not affected
  Mds:                    Not affected
  Meltdown:               Not affected
  Mmio stale data:        Not affected
  Reg file data sampling: Not affected
  Retbleed:               Not affected
  Spec rstack overflow:   Vulnerable: Safe RET, no microcode
  Spec store bypass:      Mitigation; Speculative Store Bypass disabled via prctl
  Spectre v1:             Mitigation; usercopy/swapgs barriers and __user pointer sanitization
  Spectre v2:             Mitigation; Retpolines; IBPB conditional; IBRS_FW; STIBP disabled; RSB filling; PBRSB-eIBRS Not affected; BHI Not affected
  Srbds:                  Not affected
  Tsx async abort:        Not affected
root@hbrr-proxmox:~#

yabs:

root@hbrr-proxmox:/etc/pve/qemu-server# curl -sL https://yabs.sh | bash
# ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## #
#              Yet-Another-Bench-Script              #
#                     v2025-01-01                    #
# https://github.com/masonr/yet-another-bench-script #
# ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## #

Mon Mar 10 04:58:45 PM CET 2025

Basic System Information:
---------------------------------
Uptime     : 0 days, 22 hours, 18 minutes
Processor  : AMD Ryzen 9 5950X 16-Core Processor
CPU cores  : 8 @ 3393.624 MHz
AES-NI     : ✔ Enabled
VM-x/AMD-V : ✔ Enabled
RAM        : 19.5 GiB
Swap       : 8.0 GiB
Disk       : 34.1 GiB
Distro     : Debian GNU/Linux 12 (bookworm)
Kernel     : 6.8.12-8-pve
VM Type    : KVM
IPv4/IPv6  : ✔ Online / ❌ Offline

IPv4 Network Information:
---------------------------------
ISP        : Hetzner Online GmbH
ASN        : AS24940 Hetzner Online GmbH
Location   : Falkenstein, Saxony (SN)
Country    : Germany

Less than 2GB of space available. Skipping disk test...
chmod: changing permissions of './2025-03-10T16_58_46+01_00/iperf/iperf3': Operation not permitted

iperf3 Network Speed Tests (IPv4):
---------------------------------
Provider        | Location (Link)           | Send Speed      | Recv Speed      | Ping           
-----           | -----                     | ----            | ----            | ----           
Clouvider       | London, UK (10G)          | busy            | busy            | 22.7 ms        
Eranium         | Amsterdam, NL (100G)      | busy            | busy            | 10.3 ms        
Uztelecom       | Tashkent, UZ (10G)        | busy            | busy            | 94.6 ms        
Leaseweb        | Singapore, SG (10G)       | busy            | busy            | 176 ms         
Clouvider       | Los Angeles, CA, US (10G) | busy            | busy            | 163 ms         
Leaseweb        | NYC, NY, US (10G)         | busy            | busy            | 92.4 ms        
Edgoo           | Sao Paulo, BR (1G)        | busy            | busy            | 200 ms         

Geekbench 6 test failed. Run manually to determine cause.

YABS completed in 1 min 44 sec

storage:
root@hbrr-proxmox:/etc/pve/qemu-server# df -h
Filesystem Size Used Avail Use% Mounted on
udev 9.8G 0 9.8G 0% /dev
tmpfs 2.0G 1.5M 2.0G 1% /run
/dev/mapper/pve-root 35G 3.8G 29G 12% /
tmpfs 9.8G 43M 9.8G 1% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
/dev/fuse 128M 16K 128M 1% /etc/pve
tmpfs 2.0G 0 2.0G 0% /run/user/0
root@hbrr-proxmox:/etc/pve/qemu-server# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sda 8:0 0 368K 1 disk
sr0 11:0 1 2K 0 rom
vda 253:0 0 300G 0 disk
├─vda1 253:1 0 1007K 0 part
├─vda2 253:2 0 1G 0 part
└─vda3 253:3 0 299G 0 part
├─pve-swap 252:0 0 8G 0 lvm [SWAP]
├─pve-root 252:1 0 35G 0 lvm /
├─pve-data_tmeta 252:2 0 2.4G 0 lvm
│ └─pve-data-tpool 252:4 0 235.2G 0 lvm
│ ├─pve-data 252:5 0 235.2G 1 lvm
│ └─pve-vm--100000--disk--0 252:6 0 230G 0 lvm
└─pve-data_tdata 252:3 0 235.2G 0 lvm
└─pve-data-tpool 252:4 0 235.2G 0 lvm
├─pve-data 252:5 0 235.2G 1 lvm
└─pve-vm--100000--disk--0 252:6 0 230G 0 lvm
root@hbrr-proxmox:/etc/pve/qemu-server#

JabJab · March 2025

Nice YABS, nothing worked, very helpful :-D

lowenduser1 · March 2025

@JabJab said:
Nice YABS, nothing worked, very helpful

Yabs please

Yabs: no

host_c · March 2025

Try this:

ACPI Support: YES ( windows needs this ) - by the way, without that it usually does not work at all.

DeadlyChemist · March 2025

@host_c said: ACPI Support: YES ( windows needs this ) - by the way, without that it usually does not work at all.

already enabled...

host_c · March 2025

I have nothing,

I can just best guess it has something to do with storage, and not CPU.

Can you benchmark the LVM in that proxmox?

host_c · March 2025

and take off use tablet for pointer, tr to take off also hot plug for like disk, lan and usb.

TimboJones · March 2025

To confirm, you're running a Hostbrr VPS, not a dedicated server, right?

Howdy, Stranger!

Categories

In this Discussion

(help) Awful performance on Windows 2022 via Proxmox

Comments

Howdy, Stranger!

Quick Links

Categories

In this Discussion

(help) Awful performance on Windows 2022 via Proxmox

Comments