You need to do a review of the IRQ addresses and the peripherals running in each. I would think that you need to isolate the video card in a specific IRQ. That error indicates that the bandwidth for one of your IRQ addresses is not cablable of running the periperals addressed to it. The other hint that it might be the PCIe video card interrupt is that this issue worsens when playing games and the card is sucking up the max bandwidth for that IRQ address. You need to right click on my computer and then get a visual on each IRQ address and what peripherals are residing there. You may have to manually set the IRQ for your PCIe card so that it will run alone.
Edit: Did you run memtest86 a full 24 hours? Becasue that is the best choice for this error although I would review the PCI bandwidth issue. another issue may be CPU core temperature running to high. Is it heavily overclocked?
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