Question Very poor performance w/ my peasant gaming PC?

Apr 7, 2020

My rig:
Second hand Intel Xeon Processor E3-1230 v3 stock
Amazon Warehouse NVIDIA GeForce GTX 1060-6GB ZOTAC stock
Second hand Gigabyte Z87X-D3H-CF
16gb RAM Crucial DDR3 @ 1,596 MHz
550W PSU
SSD for system and games
Drivers all up to date
Cooler: brand new Noctua NH-L9x65
1080p 60hz display

The system runs quite normal, there are no freezes or blue screens or failures, everything seems to be fine and dandy until you put pressure on the system, like running a benchmark or playing a game.

To demonstrate its performance problem:
3700~3800 in 3dMark, abysmal framerate, while people with the same CPU and graphic card gets over 10k(;
11664 score in ChessBase, about 15% lower than other people using the same CPU;
CPU sits at 50+ degrees idle, reaches up to 100 when running the last part of Time Spy;
GPU sits at 30 degrees idle and barely gets to 70 during 100% load;
GeForce Experience recommands graphic settings of most my games to either high or max, but I can't even get to stable 60 after tuning everything, including the resolution down.

If I have a faulty CPU or motherboard, it would be very weird that only the performance and heating are impacted but the system remains stable. I just don't know where the problem is.
Apr 7, 2020
Looks like CPU cooler not seated properly, not enough thermal paste etc.
Additionally please check in taskmanager, what's running in the background.
The screws are all tight and I surely used enough thermal paste, although the CPU temp is high, the system is stable. When gaming the temperature is usually around 80 which shouldn't cause throttling.

In the background there are just the normal bunch like antivirus(AVG), steam, some other gaming platforms and chrome. and they add up to about 10% CPU usage.