When it comes to GPU cards, there are pretty much two companies to consider: AMD and NVIDIA, or “team red” and “team green” to their devoted fanbases. But you don’t really have to choose, and can, in fact, use cards from both companies in the same machine. All you need is the correct PCIe x16 lanes on their motherboard and a PSU with enough power delivery. The downside is that they don’t directly work together, and the days of NVIDIA SLI and AMD CrossFire are truly dead.
So why even do it? I found a great use for a secondary budget GPU to offload frame generation in games with the help of the Lossless Scaling app. Your monitor plugs into this secondary GPU handling frame generation, freeing up the stronger card to render the game itself.
In my setup, I used a AMD Radeon RX 9070XT for rendering, then a $100 RX 550 GPU to handle Frame Generation90 thanks to both cards operating separately, with frame generation workloads being organizeds when handling Lossless Scaling frame generation with only around 11ms latency, which is around three times more responsive when compared to DLSS 3
This approach does have its limits. First, it primarily benefits older GPUs. Two GPUs working together have to work through communication bottlenecks to effectively increase performance. Modern cards, like the RTX 5090 running DLSS 4.5/5, has enough power and speed to do this natively, and faster than a two-card setup would work.
The second issue with running two GPUs is cooling. It’s hard enough to keep one system cooled with a single GPU in its chassis, so when you add a second, it really becomes a thermal and power headache waiting to happen.
The Truth About Using Two GPUs in One PC
<img src="https://www.bgr.com/img/gallery/can-you-use-amd-and-nvidia-gpus-in-the-same-pc/the-truth-about-using-two-gpus-in-one-pc-1792085957.jpg" alt="Hellhound AMD Radeon RX 9070 XT running in a Maingear Rush gaming PC”>
I’d sooner run two separate rigs, like my MainGear Rush AMD Radeon 9070XT and MainGear Zero with an NVIDIA RTX 5090. One is for work, one is for gaming, and I know they’ll be no thermal or power bottlenecks. When people can supply their own RAM and trade in old tech for a custom-tuned gaming PC, it’s oddly a great time to upgrade despite the current market too.
For users determined to combine both brands, Windows can run both AMD Adrenalin and the NVIDIA app simultaneously, with each card driving separate monitor inputs, for example. But outside of offloading frame generation work, don’t expect for two graphics cards to join forces in the name of more frames.
Technologies like NVIDIA SLI and AMD CrossFire are completely obsolete, mostly thanks to cards moving to two-chip formats and graphics card sizes getting bigger by 2010, so combining two graphics cards just stopped making sense. Games will only use one active graphics card processor at a time, with the secondary card simply idling during gameplay unless it’s performing background tasks that have been set. But mixing an Nvidia GPU with an AMD CPU is one of the best way to play games on PC these days.
Cooling, Power, and Niche Productivity Tasks
There’s another hiccup to this whole exercise: The sheer physical clearance needed to run two current generation GPUs in one motherboard just isn’t practical, not to mention a thermal nightmare. Because motherboard PCIe x16 slots sit directly next to each other, the lower graphics card will block the air intake fans of the top card.
You could use PCIe riser cables or dedicated liquid cooling blocks to keep temperatures manageable. You’d also likely need a massive power supply of 1000W and up just to handle potential power spikes. By the time this has been implemented, builders would be near the same financial burden of having a second build.
But when does a dual GPU setup actually make sense? Running same-brand dual-GPUs can be useful for local LLM AI training and for 3D rendering in programs like Blender where runtimes can be cut down by splitting workloads. Virtual Machine pass-through can be good for different branded GPUs as they can be assigned to a VM or PC. Another key fact to remember is that PCIe lane bandwidth control performance, not processor manufacturer, although the AMD’s AM5 platform and X3D Cache technology dominates top gaming picks. Also, it’s a good idea to make sure a monitor supports both G-Sync and FreeSync if running a dual-brand GPU rig.
The bottom line though follows the saying, just because you can, doesn’t mean you should. For gaming and everyday use, just stick to one GPU or have separate builds for the sake of cooling and making sure both graphics cards last for years, not months. For high performance workloads and gaming, it might be worth looking into a liquid cooling block solution for a GPU, which would also require fitting a reservoir, pump, and piping into an already packed chassis.
