[SOLVED] Pulsating FPS in games following upgrade

[Obs1dian]

I've just upgraded my PC but kept my existing PSU and GPU. The GPU had been working well before in my old PC (i5 4th gen) and games ran generally smoothly. Now it is in my new build, when playing games e.g. Doom Eternal, the fans start "pulsing" and the FPS in game goes up and down like a yo-yo, as in 80-40-80-40 except that the counter is more of a garbled mess.

Weirdly, on my monitor when I look at the refresh rate using the built in menu the frame rate fluctuates 75hz down to 35 or so then back up every half a second.

I know the GPU is capable of running the game smoothly as I completed it on my old PC set up.

All my drivers are up to date and I've tested the PSU with a multimeter and the voltages appear to be solid. The PSU is quite old, it's a Thermaltake 750w semi modular. And when I say old, it could be 10 years old.

Temperatures for CPU/GPU/RAM etc. all seem fine.

I nearly bought a new PSU but if it could be something else I would rather not drop the cash on a new one if I don't have to.

Spec:
Ryzen 3600
MSI Mortar MAX motherboard
Crucial Ballistix 16gb DDR RAM
Sapphire Radeon RX480+ OC
Thermaltake 700w PSU
2x SSD (Crucial)
Cooler Master 240l CPU cooler

 

[Obs1dian]

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Was this card purchased new or used?

If the temp throttle point is set at 77C, that's pretty dang low. Usually it's around 90C. Might want to try flashing the VBIOS.

Not encouraging you to give up, but as an owner of an RX480 driving a 2560x1440 144Hz monitor, I can say that using an RX480 at 3440x1440 isn't going to give you good FPS in demanding games.

It was purchased new. It's awful to be honest, I never had these issues before my "upgrade". I used to run the ultra wide monitor previously with the RX480 and could live with the performance. As shown in the FurMark video, the resolution on that is very low (1024x768) and it still does the stuttering issue despite it being 110-80 FPS.

 

[tennis2]

Ah, so the card worked fine in your previous machine. Something tells me this is a software issue then (presuming you're on a new windows installation with this upgrade)

Do you have any other 3rd party software installed that would be used for GPU tuning, MSI Afterburner, Asus GPU Tweak, Sapphire Trixx, etc etc?

 

[Obs1dian]

Ah, so the card worked fine in your previous machine. Something tells me this is a software issue then (presuming you're on a new windows installation with this upgrade)

Do you have any other 3rd party software installed that would be used for GPU tuning, MSI Afterburner, Asus GPU Tweak, Sapphire Trixx, etc etc?

Sorry for delay in response, I've been away.

Yes on a new Windows installation. I am using Sapphire Trixx. Think this could be a problem?

In fact, I've been using Sapphire Trixx to underclock the card which alleviates the problem a little bit but not much.

Still get the issue in Doom Eternal and DOTA 2. Interestingly, Tomb Raider (2013) seems to run very well.

Fans spin up something awful though.

 

[Obs1dian]

For anyone reading this and having similar issues it appears I've fixed it. Took graphics card apart, cleaned all contact points, applied new thermal paste. Haven't been able to replicate problem since.