cpu throttling but temps fine

[zvinarija]

Hello guys! So today i swaped my i5 3570k for i7 2600k and i was hoping to overclock it around 4.5 GHz. But when i overclocked it to 4.3 with around 1.27 vcore and started small fft on p95 version 26.6 after a minute or two my frequency would start to drop to 1.6 ghz even thou my temps are like 75 C max. After that i started to lower the vcore and frequency to avoid this and now I'm at 4.0 GHz and stock vcore of 1.20 V. Any help would be apreciated
My specs are:
motherboard: gigabyte z77 hd3
ram: 1x8 gb crucial 1600 MHz
psu: corsair tx 550m
gpu: gtx 1060 3 gb
cooler: cm 212 evo

 

[zoltan.boese]

I found these guides
http://www.clunk.org.uk/forums/overclocking/39184-p67-sandy-bridge-overclocking-guide-beginners.html
https://www.tomshardware.com/reviews/sandy-bridge-overclocking-efficiency,2850-4.html
I also read others set the vcore higher, up to 1,35V at 4,5GHz. Not having enough power/ high enough voltage can lead to lowered clock speeds.

 

[zvinarija]

tnx on a quick reply. I will try to up the voltage but I was at 1.3 vcore at 4.3 GHz and it kept throttling like that so I assumed it's something else

 

[zvinarija]

I tried upping the voltage but it just started throttling faster. I don't know if there is some setting in bios I should change or my motherboard just can't deliver the power or something like that

 

[zoltan.boese]

Then it will be thermals after all. It should only throttle at 105 degrees, and the information I found is rather contradictory. Here intel writes: https://ark.intel.com/products/65520/Intel-Core-i5-3570K-Processor-6M-Cache-up-to-3_80-GHz Tcase is 67.4°C which is really low. Furthermore:
Tcase (CPU temp) = 67C
CPU / Core offset + 5C
Tjunction (Core temp) = 72C
Tj Max (Throttle temp) = 105C
source: http://www.tomshardware.co.uk/answers/id-2436197/3570k-safe-temperatures.html
Others have stable overclocks at 81-82°C. I am sorry, but I am out of ideas.

 

[zvinarija]

My cpu temps are definitely ok, but I think cpu is throttling because motherboard is heating and lowering voltage to the cpu and subsequently cpu frequency is droping. I'm gonna have to buy a better motherboard to oc this chip more. It must be motherboard because this cpu can go as high as 98 C before throttling

 

[GhislainG]

My cpu temps are definitely ok, but I think cpu is throttling because motherboard is heating and lowering voltage to the cpu and subsequently cpu frequency is droping. I'm gonna have to buy a better motherboard to oc this chip more. It must be motherboard because this cpu can go as high as 98 C before throttling

You are correct; the VRM gets too hot and it throttles the CPU to protect itself. Lowering the voltage will help as long as the CPU still is stable (find the lowest stable voltage and then increase it a bit). Increasing the voltage as you did makes it worse because more power is drawn from the VRM and the CPU also runs hotter.