Question Newly build PC: horrible performance, FPS tanking over time

[Bleachcz]

Hey guys, I feel quite hopeless and might need some help.

I built a new PC for my GF, the PC is as follows:
i5 6400 (I wanted to try BCLK OC BIOS, but sadly doesn't work on this MB, so i5 6600K comming) - BQ! Dark Rock Pro 3
MSI Z170A MPower Gaming Titanium
8GB Patriot Viper (@3200Mhz 15-19-19-36)
180GB Corsair GS as system drive
GTX770 (@1267MHz core, 8000MHz memory) - Prolimatech MK-26 + 2x120cm
Seasonic 650W Focus Plus Gold
All in well ventilated NZXT Phantom 410

And my problem is this:

Most parts were salvaged, from my PC (apart from CPU - 7600K@5GHz and 16GB of HyperX Savage DDR4) and with that system I could play Wither 3 on medium details 1440p without any issues. This PC barely scrambles 10FPS in open world on low details 1440p.

The second issue is FPS falling in time.

For example: Combat tutorial in Witcher 3: starts at approx. 36FPS and ends with 15, even though the scene is pretty much still the same.

Other example might be Unigine Heaven and valley benchmarks: while on first loop the FPS is decent (30-120FPS), but from loop 2 onwards i get 15-60FPS, pretty much halved across the board. It happens each and every time I run these.

Troubleshooting I've tried so far:
- Storage is not the problem, same happens on different SSDs and SATA ports

- I've got latest drivers for my GTX770

- W10 was installed clean

- This happens on stock values as well (for all components combined: RAM stock JEDEC, GPU stock)

- Temperatures are not the issues here due to the overkill cooling I'm running (GPU OC 56°C load, CPU 40°C load)

I have no clue what is going on, absoluytley no clue. Please help!



(Next week I might take out the i5 7600K from my PC and try it here, same with memory and my Vega 64)

 

[tennis2]

Where did you plug the monitor cable into? The ports near the USB ports (on the mobo rear IO panel) or into the ports on the graphics card itself?

 

[Bleachcz]

Display port straight into the graphics card.

 

[Bleachcz]

So I just tried a bit more troubleshooting:

• Installed newest BIOS for my MB
• reainstalled my nVidia drivers (Driver Sweeper -> Guru3D newest nV drivers)
• checked both SSDs in the system with HD Tune (all green, all good)

Aaaaand, the problem persists. In heaven in an identical scene sometimes i get 7FPS, sometimes 15 and other times 40. Usually if I run Heaven after a restart, I get one of the better results (not straight 7FPS, but 20 instead).
I keep track of:
CPU usage - around 26% all core
GPU Usage - 100% (98% by Unigine Heaven)
RAM - 2,5GB out of 8GB
VRAM - 1GB out of 2GB

Usage is stable across all runs, identical almost, yet the results are vastly different.

On top of that, whenever I quit a game or benchmark (be it Sims 4, Witcher 3 or Unigine Heaven) the PC freezes, and then there are two cases what might follow:

1. PC is frozen forever and I have to do a hard reset
2. PC does a black screen, then recovers. This happens each and every time after I close either of the three applications. It never occured during W3 or Unigine Heaven, but it was observed in Sims 4 with grey screen instead of black screen. It doesn't matter wheter I'm running fullscreen or not.

Now I had the PC freeze up on me after booting to windows and trying to unlock it. Full hard reset type of freeze.

At this state, the PC is unusable. I have no clue what to do with it other then starting to change out components.
I have i5 7600K, Vega 64 and 16GB of HyperX memory on hand, that are in my personal PC, so next week I'll probably pull these from my PC and stry them in this one. Because I'm out of ideas.