Question Performance problems with RTX 2070 and Ryzen 7 1800X?

[Lari0L]

Hey guys,
I'm new here. I'm hoping that you could help because I am absolutely stumped.

I built a PC two years ago with the following specs:

• Gigabyte RTX 2070
• Ryzen 7 1800X
• ASUS ROG STRIX B350-F Gaming
• 16GB G-Skill RAM 3000Mhz
• Cooler Master 600W PSU
• Samsung 970 EVO 1TB

Now here's the problem:
This build was doing fine until 1-2 months ago. I will use AC Odyssey as an example because that's what I'm currently mainly testing with. The PC ran Odyssey fine without any problems a few months ago. Recently I decided to run the game again and now I'm experiencing heavy framedrops and lower fps than before. Lowering settings as much as I can makes absolutely no difference in fps. The performance is also pretty inconsistent. Sometimes I get up to 60fps, sometimes I can't get more than 30fps.
And this isn't limited to AC Odyssey. I also tested e.g. Witcher 3. The performance is around 40-50fps on 1440p and medium settings with a few framedrops every few seconds to around 30fps.

What I did:

• I tested every component by swapping it with different components. And with every component I mean: CPU, GPU, mobo, PSU, RAM, SSD, so basically the whole computer.
• I did a BIOS update
• Changed thermal paste of the CPU, but temps weren't that high before that anyways
• Updated and reinstalled drivers and Windows

There's an additional issue, I don't know if it's related: there sometimes are random reboots. The screens just go black and the PC immediately restarts. This didn't happen very often and it started happening only about 3 days ago. The performance problems including the framdrops are happening since 1-2 months. Because of this I initially thought that maybe the PSU was fault, but it happened with a different PSU (Corsair TX650M), too.

I also swapped the GPU with a Radeon RX 5700 XT and the performance didn't really improve or decrease.

I have no clue what else I could check or what the problem may be. I'm really grateful for any kind of tips or clues that could point toward the right direction. Please tell me if you need to know anything else.

I will remain awake for a while, but if I don't respond right away it's because it's 1am here and I have to go to work in 5 hours

Thanks.

 

[Lari0L]

Update: we did some more testing after that and eventually the mobo just refused to post. I followed the checklist that's stickied to this forum and checked everything. Only thing I didn't try yet is taking the mobo out of the case and starting the PC. I will try this later and if that doesn't work I will send the mobo to the manufacturer, because I still have valid warranty and this isn't the first time we had this kind of problem with it (the first time it just eventually, so we just ignored it then).