Bottlenecking causing cpu to overheat?

[nahuelalcaide]

hello there,
i have recently purchased a new graphics card (Msi gTX 960 4gb), and i have noticed that mi cpu are considerably high. On idle my cpu is hovering arround 40 ish ºC, and in full load it can reach 100ºC!, all of this according to msi Afterburner and Open hardware Monitor.
Having already reaplied thermal paste, checked that my heatsink (intel's stock one) was well attached and messed arround with my fan setup, temps seem to stay more or less the same no matter what I do.
I've already had a couple of crashes due to overheating.
There are benchmarks on Youtube with my CPU-GPU combo and no overheating is there to be seen.
I will greatly appreciate if someone could help me.

edit: Just noticed that as soon as i close a game CPU temps go down like 50ºC in less thasn 10 seconds

specs:
CPU: i5 2300 2.8GHz 3.1GHz turbo boost
GPU: MSI GTX 960 4gb Factory OC
RAM: 2x4GB sticks 1333MHz
Case: NZXT s340, 4 fans, top and back are intake and both front ones exhaust
PSU: old sentey unsertificated psu, getting a new one in a few days

 

[TerryLaze]

No bottleneck should not affect temps,especially not in idle.
A faster GPU will force your cpu to work harder to get better FPS but a CPU is designed to be able to run at 100% within normal temps.
The only thing I can think of is that the GPU cooler blows hot air towards your CPU or that the added hot air from the GPU cooler adds to the temps within the case causing the CPU temps to be higher.

Also did you clean your cooler when you reapplied the thermal paste?

 

[nahuelalcaide]

No bottleneck should not affect temps,especially not in idle.
A faster GPU will force your cpu to work harder to get better FPS but a CPU is designed to be able to run at 100% within normal temps.
The only thing I can think of is that the GPU cooler blows hot air towards your CPU or that the added hot air from the GPU cooler adds to the temps within the case causing the CPU temps to be higher.

Also did you clean your cooler when you reapplied the thermal paste?

Yes, I cleaned my heatsink, It had some nasty blobs of dust and the thermal paste was like 6 years old. Temps did not change at all.
Also, the air pumped out of the case seems pretty cool, even on full load. Could the thermal sensor on my CPU be wrong and the crashes due to something else?

 

[Ecky]

Possible, but unlikely. I would check again that the heatsink is mounted securely and that your thermal paste application was good. Sandy Bridge (2xxx) CPUs all had their IHS soldered to the die and so their temps should not degrade over time, and nor should the sensors fail.