I’d recommend not trusting anything from that reviewer! Maybe send them a comment asking them on what basis they are saying that?
EPYCs love all the GPUs you give them, what else are 128 PCIe lanes for?
I’m using a desktop with a 74F3 on a ROMED8-2T here for over 2 years, no problems at all for me using various Nvidia cards (and AMD cards) in different configs:
Used a 2080Ti for a year, multi booting Linux, FreeBSD and Windows 10
Added a 4080, using the 2080Ti for VMs
Replaced the 2080Ti with a Radeon RX 7800XT as the host card, and the 4080 for VMs (mostly Windows games, and OpenCL apps).
The latest ASRockRack BIOS updates add ReBAR support too (confirmed working here: BAR 1: current size: 16GB), which might help some types of VRAM access patterns. Check if that matters to you because not all boards support ReBAR.
One thing that I have personal experience with is the compatibility with consumer cards and server operating systems. When you use either Linux or Windows 10 or Windows 11 on the machine it will work fine with consumer GPUs, but there are NO drivers for consumer GPUs for Windows Server at all! An Nvidia 3090 won’t work on Windows Server 2022. Windows Server will refuse to install drivers for consumer cards.
I’ve read that maybe somewhere out there exists hacks to make it work, but there is no official support for this.
The hardware will be just fine with each other.
Software wise, you could be looking at some petty “I am a consumer driver, and this is a Server OS”, especially in Windows/MS Server land.