RTX 2080 Super 100% workload problem

[WurstTurbo]

Greetings from Germany,

my brother build himself a new desktop system and we are far off of beeing computer experts and he has a problem we cant figure out. 

His Specs:
Mainboard: MAG Z390 TOMAHAWK
CPU: i7-9700KF
GPU: RTX 2080 Super

RAM: DDR4 3600 16 GB

His problem:

He plays relative old games like Forza Horizon, Rainbow 6 Siege or GTA5 an all his games crash at several playtimes. And even on low quality settings in the games the Worklaod of his GPU is allways on 100%. But at Forza Horizon his CPU Workload is on 100% and his GPU only at 1% on only High settings and FullHD.  Sometimes the games just close themselfes or he gets a bluescreen with following error messages: 

system service exception

Memory management

Critical Structure curroption

 

I'm a littlebit better with Pc's than he is and i looked into his software via teamviewer but i couldnt find any errors theire.
I checked his drivers, compatibility and if everything is detected by the system. I couldnt find any answers on other websites so i hope you can help has thanks in advance.

WurstTurbo
 

(Edit: The Pc doesnt crash when it is idle. But it crashed as he whatched some YouTube videos)

[Princess Luna]

Did he reuse an old Windows install?

 

I'd start with DDU in safe mode and reinstall (NON DCH) latest drivers fresh new for troubleshooting.

 

Also worth trying to leave memory and CPU at stock to ensure there's no stability issues.

[just that pc guy]

20 minutes ago, WurstTurbo said:

Greetings from Germany,

my brother build himself a new desktop system and we are far off of beeing computer experts and he has a problem we cant figure out. 

His Specs:
Mainboard: MAG Z390 TOMAHAWK
CPU: i7-9700KF
GPU: RTX 2080 Super

RAM: DDR4 3600 16 GB

His problem:

He plays relative old games like Forza Horizon, Rainbow 6 Siege or GTA5 an all his games crash at several playtimes. And even on low quality settings in the games the Worklaod of his GPU is allways on 100%. But at Forza Horizon his CPU Workload is on 100% and his GPU only at 1% on only High settings and FullHD.  Sometimes the games just close themselfes or he gets a bluescreen with following error messages: 

system service exception

Memory management

Critical Structure curroption

 

I'm a littlebit better with Pc's than he is and i looked into his software via teamviewer but i couldnt find any errors theire.
I checked his drivers, compatibility and if everything is detected by the system. I couldnt find any answers on other websites so i hope you can help has thanks in advance.

WurstTurbo
 

(Edit: The Pc doesnt crash when it is idle. But it crashed as he whatched some YouTube videos)

did you scan with antivirus? it could be a gpu mining one