i7 4790K with overclocking – one core significantly warmer than the rest
i7 4790K with overclocking – one core significantly warmer than the rest
Hey everyone,
first of all, I'm new to overclocking but I'm adapting and reading a lot to not make any mistakes.
■ CPU: Intel i7 4790K @ 4.3GHz / Vcore 1.125V Adaptive + 0.025 Offset / Vin 1.55V
■ Cooler: Thermalright HR-02 Macho Rev. A - Air Cooler
■ MB: Z97 Extreme4
■ GPU: Geforce GTX 980 Ti - not overclocked
■ RAM: 2x 8GB Team Vulcan @ 1600MHz
■ Fans: 2x In (front) / 2x Out (behind and above CPU) - all bequiet ShadowWings 120mm
■ Power: bequiet! 450W Gold+
Now when I'm in idle, everything is okay, the cores run between
32-39°C
but when I stress test with RealBench then
Core 0
starts rising rather fast to around
70*C
and sneaks up to
85-90°C
after a few minutes. The
other cores
remain at
65-70°C
.
While gaming CPU heavy games I even have spikes to 95-100°C...
Did I make any obvious mistakes? Could it be that the thermal compound is not well distributed? I used a small dot the size of grain of rice but did not distribute it. I did not reseat the cooler yet, should I try that?
On that note, how important is the fan above the CPU? I did not notice a significant cooling change after adding it.
Thanks!
xL
Check your voltage using a tool like CPUz on your second monitor to observe its behavior under heavy use. You might need to reapply the paste, but it could help. Temperatures are extremely high; you may want to reduce the voltage. Are you referring to the side panel fan? That mainly helps cool the graphics card.
Monitor your voltage using tools like CPUz on your second screen to observe its behavior under heavy use. You might try reapplying the paste, it could help. Temperatures are extremely high; you may need to reduce the voltage. Thanks for your reply. The unusual part is that even though I set 1.125V as Vcore in CPU-Z, HWMonitor only shows 0.768V when idle. Could this be due to the adaptive vcore setting? Should I switch to override mode? Isn’t that already undervolting? I also tested with default BIOS settings, and during a real benchmark, three cores reached 65-70°C after 10 minutes, with core 0 showing spikes up to 95°C. I’ve attached a screenshot of the HWMonitor voltage readings – the peak values match those from RealBench Load.
xLiqxo :
Greetings everyone,
I'm just starting out with overclocking and I'm learning a lot to avoid mistakes.
■ CPU: Intel i7 4790K @ 4.3GHz / Vcore 1.125V Adaptive + 0.025 Offset / Vin 1.55V
■ Cooler: Thermalright HR-02 Macho Rev. A - Air Cooler
■ MB: Z97 Extreme4
■ GPU: Geforce GTX 980 Ti - not overclocked
■ RAM: 2x 8GB Team Vulcan @ 1600MHz
■ Fans: 2x In (front) / 2x Out (behind and above CPU) - all bequiet ShadowWings 120mm
■ Power: bequiet! 450W Gold+
Now during idle the system runs smoothly with cores between 32-39°C,
but under stress testing with RealBench the situation changes quickly:
Core 0 begins to heat up rapidly reaching around 70*C,
then climbs to 85-90°C after a short time, while the other cores stay at
65-70°C.
While playing CPU-intensive games I even reached temperatures of 95-100°C...
Could there be any clear errors? Might the thermal paste not have been applied well?
I tried placing a grain of rice-sized dot on the CPU heatsink but didn't spread it evenly. I haven't re-seated the cooler yet—should I do that?
Regarding the cooler placement above the CPU, I didn't notice any major cooling improvement after installation.
Thanks!
The thermal paste seems not to be spread uniformly across the CPU, possibly due to bubbles or uneven coverage, which might cause inconsistent temperature readings. After redoing it today, the distribution appeared more consistent, but the remaining three cores are noticeably cooler compared to Core0, with a 20°C difference.
Can you confirm if you're just increasing the speed of a single component? I understand your Asus setup supports this.
If temperatures shift after installing or repositioning the cooler, it may indicate an issue during mounting. A rise to 20°C is notable when cores are under load. Check the temperatures at factory settings and see if they differ between cores. At stock speeds, the 4.3GHz rating isn't a major jump; the 4790k can hit around 4.4GHz on one core during full load, reaching 4.2GHz when all four are under heavy use. Look for temperature differences at default settings and work to minimize them.
When installing the cooler, tighten the screws in an "X" pattern—top left, bottom right, top right, bottom left—and turn them slightly at a time, moving around until everything is snug. This helps ensure even contact between the cooler and CPU. Avoid interference from other components like RAM or VRMs that could affect tightening.
The room temperature matters too. If it's 20°C or higher, it can impact cooling performance. Refer to articles on thermal paste application for tips; typically, the 'X' pattern is used without overlapping lines to prevent a dense central mass. It’s usually not necessary to spread paste on both CPU and cooler base, as this increases the risk of excess. Clean both surfaces with isopropyl alcohol and a lint-free cloth—alcohol dries quickly, leaving everything clean.
A larger power supply might be beneficial for this system. Running a 1080Ti card at 450W is challenging; Nvidia suggests 600W, even if you're cautious. Using 550W is still significantly higher than 450W and could strain the system.
SinxarKnights :
Could it be that you're only increasing one core's speed? I understand my Asus board supports this. When I used OC settings before, I made sure to select "All Core" and carefully verified all Core Frequencies after the changes. It worked fine. Now I'm using the standard settings with Turbo Boost turned off, yet I still notice a 20°C gap between Core0 and the others.
synphul :
If temperatures fluctuate after installing or removing the cooler, it might indicate an issue during installation. A 20°C difference is quite notable between cores under load. What are the normal temperatures at stock settings? Have you reset the BIOS completely and tested with default configurations to see how the readings compare? That could be a good starting point—remove any offsets or overrides. The 4.3GHz figure isn't a major overclock; the 4790k should hit around 4.4GHz on one core under full load, and 4.2GHz when all four are under heavy use. Check if temperature differences remain between cores at stock levels, and work toward minimizing that gap. Thanks for your thorough advice. I attempted full defaults in two versions: Turbo Boost On and Off. In both cases, temperatures varied by at least 20°C. With Turbo On, RealBench shows higher temps (Cores 1-3 at 75-80°C, Core0 at 100°C after a few minutes) compared to 15 minutes with Turbo Off, where temps settle between 65-70°C for Cores 1-3 and 95°C for Core0.
Currently, I'm sticking to stock settings with Turbo Boost off because the temperatures have improved slightly, though this isn't a permanent fix.
synphul :
Ensure you tighten the cooler screws in an "X" pattern—top left, bottom right, top right, bottom left—and turn them a few turns at a time around the CPU. This helps achieve a more uniform fit. Avoid any obstructions such as RAM or VRM heatsinks that could interfere during tightening.
In addition to the diagonal screws, I applied the paste and verified the pattern was even across the cooler and CPU surface. After cleaning with Isopropanol, I repeated the process to confirm consistency. It seems the even distribution suggests the issue isn't severe.
What are the ambient room temperatures? If it's 20°C or 30°C in your space, that could affect overall cooling performance. Room temperature typically ranges between 20-25°C, though this can vary with weather.
Place a small droplet in the center of the CPU and allow the cooler's cooling effect to distribute the paste, without handling it or lifting it to avoid creating air bubbles.