I am pulling my hair out trying to boot ESXi 6.0U2 with 2 GPUs installed. With the default BIOS settings (and latest BIOS version), one GPU will prevent any VM it is attached to from starting at all and the error logs (and then Google) point to disabling a BIOS option called Memory Mapped I/O Above 4G. However, when I do that, at boot I get a BIOS error about" PCI out of resource" and ESXi won't even boot. So then I turn Memory Mapped I/O back on and have set the size to all of the different options, but I always get the same error when trying to start a VM with the 2nd GPU.
So I seem to be in a pickle. It doesn't matter which slot I use, whichever GPU ends up being in the non CPU1 primary slot ends up not working (when ESXi is able to boot). I've tried the CPU1 slots and the CPU2 slot. There are no other PCIe cards installed. It seems like turning off option roms might help with booting with MMIO above 4g disabled, but I can't find any option to turn off PCIe slot option roms, only the onboard Ethernet. I'm really pulling my hair out here, thanks for any advice anyone may have.
So I seem to be in a pickle. It doesn't matter which slot I use, whichever GPU ends up being in the non CPU1 primary slot ends up not working (when ESXi is able to boot). I've tried the CPU1 slots and the CPU2 slot. There are no other PCIe cards installed. It seems like turning off option roms might help with booting with MMIO above 4g disabled, but I can't find any option to turn off PCIe slot option roms, only the onboard Ethernet. I'm really pulling my hair out here, thanks for any advice anyone may have.