Stress-testing Multiple GPUs at once using one motherboard?

Hi there, I have a question that's been running through my head for the last couple of days. I'm not exactly proficient in this side of things, so I was hoping you (in your infinite knowledge) may be able to help. Let me begin.

I work for a company that builds and sells industrial PC's for an international market. I joined about two weeks ago, give or take a day, and the first thing that struck me about this company (not naming any names) is that they don't have any true test rigs to test out any of the components. All the parts the company buys up are bought to go straight into machines, tested with the rest of the PC's hardware, and sent out to the customer. All well and good at the time, however if a graphics card or an SBC is RMA'd to us with a fault, how are we supposed to test them? This is the problem I've been asked to address.

Primarily, I'll want to find a way that I can test a number of PCI-E graphics cards at once. I've been looking into motherboards with more PCI-E x16 lanes, and have happily stumbled upon the MSI X48 Platinum with 4. My question to you all is: Is it possible to have multiple GPUs installed in a motherboard, not using SLI or CrossFire, and to use a piece of software to stress test each card at once? I understand FurMark can't test more than 1 GPU at a time, however I've heard rthdribl can be allocated to different GPUs in Task Manager so I'd probably use this software to do it.

tl;dr: Can I slot differing graphics cards into an MSI X48 Platinum (or other multiple-PCIE motherboard) and use software to stress test each GPU at the same time without using CrossFire/SLI? If so, would rthdribl be the best software to do it?


Cheers!