Question CPU does never reach base speed when on load

[Edge0410]

Hello. I have quite an old rig based on an AMD X4 870K (Base speed 3.9 - TURBO 4.1) I managed to get an rx 570 strix gaming oc at around 90 bucks and,being quite an overkill for this cpu, i tried to overclock it a bit since i was experimenting bad times with this cpu along the time. The thing is i realised after a 4.2 GHZ OC, everything seemed fine at 1.37V uniil i ran a cpuz benchmark. After that point,as soon as i am starting the bench the cpu freq goes down to 3.7 and stays there while on full load. I tried increasing/decreasing voltage but i couldnt make something stable due to my pretty old motherboard ( A68HM-P33 v2). I cant intend to make a cpu upgrade until next summer so i am a bit in need to make it work with this rig. Can anyone help me with this weird thing?

Also, the result on the benchmark are horrible. A E8500 dual core almost beats my cpu on multi threading and BEATS HARDLY my 870k on single thread - 280 vs 218 score.

I need to specify that i tried doing more stress test like cinebanch,aida64 and things like that. Everytime(including gaming on every single game) my cpu doesnt get higher then 3.7 ghz EXCEPT WHEN IT IS UNDER 20% LOAD/UTILIZATION.

here's my cpu under a cpu-z stress test

 

[jay32267]

Have you checked the temps?

 

[Edge0410]

The temps are quite decent despite of the 95W TDP of this old cpu... around 45-50 degrees when idle, 60-65 degrees at the most while stressed

 

[njcaochen]

The temps are quite decent despite of the 95W TDP of this old cpu... around 45-50 degrees when idle, 60-65 degrees at the most while stressed

before 2020, my 870k can't even fullload, only 90% load on 3.9GHz, till pay 6USD buy an AMD S3.0 cooler replace red aluminium block cooler, now my 870k oc 4.4Ghz 100%load , because red aluminium block cooler's brass column out not smooth, 870k's tempwall is only 70°C