OS Recommendation / Experience?

[rvandenbrink]

I've got a Gigabyte motherboard with 7 R9-280's in it (using USB risers)
My thought was to install ESXi so that I could move GPU's between VMs as needed. ESXi sees them all, but can only assign 4 cards (8 PCI devices) to a VM, so isn't going to be a good platform for me.
I then tried using Ubuntu, but that distro only seems to see the GPU's on one PCI bus (4 cards).
Has anyone had a similar experience? Do other distro's seem to deal better with multiple PCI busses?

[epixoip]

If both Ubuntu and ESXi are only seeing four cards, then it sounds like you have another issue going on. Maybe you can provide a bit more details about your setup.

[rvandenbrink]

Gigabyte z97x G1 Wifi-bk
F5 Firmware for the motherboard (one version back from newest, plan to update)
7x Sapphire r9 280x's
That's about it ...

ESXi sees all the cards, but it has a limit on how many PCIe resources can be assigned to a VM using VT-d. 8 resources = 4 cards in this case, each card looks like 2 devcies to PCIe.

Just was wondering if I had tripped across some dumb ubuntu + pcie or ubuntu + gigabyte thing

[undeath]

Maybe you're missing some chipset driver on ubuntu?