Question Lag even when utilisation is low?

[Aziren2001]

I have upgraded my pc to a i5 13600K, hoping to improve fps in most games, to which it has
but I am still having a major issue with lag, despite the fact the framerate is high (100+fps) and the Latency on the cpu and gpu are both below 10MS
Nvidia Geforce overlay is registering "Average pc delay" as 40+ MS, but I am not sure what is causing this.
What could be causing this constant stuttering? as it is making it unplayable?

Spec:
i5 13600K 14 CORE CPU
1X16GB DDR4 RAM STICK 2400MHZ
Gefore rtx 3060 12GB
Gigabyte Z790 D DDR4 Motherboard
Kolink 500W PSU
120GB 2.5inch SSD
1tb HDD 7200 RPM

 

[Lutfij]

I have upgraded my pc to a i5 13600K, hoping to improve fps in most games, to which it has
What did you upgrade from? Meaning what were the parts that you'd upgraded to now?

Kolink 500W PSU
If the PSU has been in service for a while, please mention the age of the unit. Mind sharing a link to the unit you're working with?

BIOS version for your motherboard at this moment of time?

 

[Aziren2001]

I have upgraded my pc to a i5 13600K, hoping to improve fps in most games, to which it has
What did you upgrade from? Meaning what were the parts that you'd upgraded to now?

Kolink 500W PSU
If the PSU has been in service for a while, please mention the age of the unit. Mind sharing a link to the unit you're working with?

BIOS version for your motherboard at this moment of time?

Bios version I will get for you in a moment, I did literally install it today so I have not checked that yet (This issue happened on my previous system)
The PSU is old, 5+ years old at least, I understand this could be contributing.