Hi.

I recently purchased a used MSI GTX770 gaming oc. Bought it, fitted and tested (Heaven 4.0) for a few minutes until I was happy. Waited for the weekend and played some COD:IW and this is where my problem started.

I'd play fine for a bit and then suddenly fps would drop below 10fps from 60fps. I have the in-game fps indicator on. After this happened a few times I checked out loads etc. on GPU-Z and saw that the gpu was running PCIe 3.0x16 @ x1 3.0 and the bus interface load was running at max. I removed the gpu, blew out the PCIe slot and refit the GPU. GPU was now running at x16 3.0 and COD:IW was now playing great, better than before. For a bit.

Last night I decided to finish playing Black Ops 3, seeing as it's only take up space on my pc. An hour in and the same thing happened. Checked GPU-Z (it's always running in the background, I like to monitor the temp) and it was running at x16 3.0, but the bus interface load was suddenly on max again. FPS stayed below 10fps until the bus interface load dropped to normal conditions again. This happened twice before I switched of the game.

What is causing the bus interface load to run max every now and then, and why does this drop the fps to below 10? Also, probably unrelated, but in MSI Afterburner the values of the core clock and memory clock are not listed on the adjustable sliders.

Previous gpu was a R9 270X and had no issues. I used DDU before installing latest Nvidia drivers.

My specs: CPU: i5 3340

mobo: MSI H77ma-g43 (latest bios update)

RAM: 2x 8gb Apacer Black Panther 1600mhz

PSU: Coolermaster rp-650-pcar 650w

GPU: MSI GTX770 GAMING OC

HDD: Seagate 500gb WD 1TB

Windows 10 Professional