Intel Arc Pro B70 gets Linux BAR-resize workaround
A Reddit tutorial describes a software-only workaround for getting Intel’s Arc Pro B70 working on a Dell PowerEdge R730xd-class server that lacks native ReBAR support. The author claims that, on a Linux kernel new enough to expose PCIe BAR resizing through sysfs, a boot-time script can temporarily unbind the GPU, expand BAR 2, and rebind it to `vfio-pci`, allowing the card to initialize for LLM inference after enabling Above 4G Decoding and `pci=realloc`. The post is framed as a practical archive for users trying to use the B70 on older enterprise hardware rather than a polished benchmark or upstream-supported method.
Hot take: this is a clever infra hack, but it reads as a fragile, highly platform-specific workaround rather than a broadly reliable deployment recipe.
- –The core idea is to use Linux’s PCIe BAR resizing support to sidestep missing native ReBAR on older Xeon-era server platforms.
- –The post’s value is operational: it turns an “XPU device count is zero” failure into a boot-sequence problem instead of a dead end.
- –It depends on several strict prerequisites: kernel support, `Above 4G Decoding`, `pci=realloc`, driver blacklisting, and correct vfio timing.
- –The script and service design are plausible, but this is the kind of setup that can break with kernel, firmware, or Proxmox changes.
- –For LLM users, the appeal is obvious: a 32GB Arc card on older server hardware is attractive if the workaround is stable enough.
DISCOVERED
9d ago
2026-04-02
PUBLISHED
9d ago
2026-04-02
RELEVANCE
AUTHOR
Dave_from_the_navy