Guides and notes on Proxmox VE — clustering, storage, VMs and containers.
Proxmox VE is open-source software for running servers as virtual machines and containers on your own hardware.
These posts cover running it day to day: clusters, storage (including Ceph), virtual machines and containers, networking, and backups.
PCIe Resizable BAR and Modern GPUs — Intel Arc, NVIDIA and AMD
Resizable BAR lets the CPU map a GPU’s whole framebuffer instead of peering at it through a 256MB window. Intel calls it required for Arc, NVIDIA enables it per game, AMD sells it as Smart Access Memory — and for AI work it changes the transfer, not the maths.
PCIe Passthrough Performance on Proxmox VE — The IOMMU Tax and How to Minimise It
Why PCIe devices lose throughput when passed through to a VM via VFIO, and the practical tuning steps that claw most of it back.
NUMA Alignment on Proxmox VE — Why It Matters and How to Get It Right
On multi-socket systems, a VM with its vCPUs on one NUMA node and its passed-through device on another loses 20–30% throughput before you’ve even looked at anything else.
PCIe ASPM and Why You Should Disable It for Passthrough
Active State Power Management saves a few watts on idle PCIe links. Under VFIO passthrough, it adds latency jitter that’s hard to diagnose and easy to fix.
PCIe MaxPayloadSize — A Free Performance Win for Passthrough
QEMU’s virtual root complex defaults to 128-byte TLP payloads. Most devices support 256 or 512. One kernel parameter fixes it.
Always Use Q35, Not i440fx — Why It Matters on Proxmox VE
The two QEMU virtual chipsets are not interchangeable. Q35 provides a proper PCIe topology that passthrough, modern Windows, and the wider KVM ecosystem all depend on.
