The water-cooled CPU is becoming excessively hot.
The water-cooled CPU is becoming excessively hot.
Hi!
This weekend I set up my first custom watercooling loop. Encountered some issues with the compression fittings, but overall it worked much better than I thought.
After completing a 24-hour leak test (which confirmed no leaks), I installed my GPU and connected the PSU to the motherboard, then powered it on.
It started up, but when I checked the CPU temperatures using "openhardware monitor," each core fluctuated between 30°C and 50°C during a single refresh tick. (During gaming it reached up to 75°C).
The pump was running at full speed, the radiator fans were active, and the PC was idle after booting up. The CPU hasn’t been overclocked yet.
I looked for any kinks but didn’t find any.
I’m puzzled as to why it became so hot, could you help?
Specs:
CPU: Intel Core i7-4790K, 4x 4.00GHz
Memory: Gigabyte GA-Z97X-Gaming GT
CPU Block: Phobya CPU-Cooler UC-2 LT
Radiator: Alphacool NexXxoS ST30 420mm
Pump: Alphacool VPP655
Fans: Corsair CO-9050017-RLED Air Series AF140-LED Quiet Edition 140mm
When I return home, I plan to:
- verify the thermal paste on the CPU block
- confirm the fans were set to the red LED mode, possibly not ideal for radiator cooling
- note that only two fans are currently on the radiator, one of which was defective
Pic:
https://postimg.org/image/d6f8vaf17/
I misunderstood that earlier. The reading should be accurate. 30C would be average, but possibly too high when idle. 30-50C seems normal for nominal to moderate load. 75C would be unusually high for a stock CPU unless you were using Prime or something similar, and even then, I’d guess around mid 60s C.
Is the pump outlet connected to your CPU block or the reservoir shown in the photo? It shouldn’t matter much, but it’s better to direct coolant to your block. Also, on the pump top, could you verify that the inlet/outlet ports are correctly labeled?
What’s your typical room temperature like? Do your temperatures remain steady or do they rise gradually over time?
You chose AF fans for your rad instead of SP fans. For radiators, static pressure fans are more suitable as they help move air through rad grilles. Corsair offers SP fans with interchangeable rings to match your color scheme in the setup. I’d focus more on performance than appearance.
The main focus here is the overclock. What voltage is your CPU running at? What temperatures are you observing at standard speeds and voltages? What readings did you notice with the previous cooler during both overclocked and standard speeds? Core-reported temperatures don’t always match real sustained temps or cooling performance. Fluctuations are normal based on workload. Excessive voltage for a given clock speed can lead to higher temps during overclocking. Have you discovered the optimal BIOS configurations for those clock speeds, or are you relying on automatic overclock settings—or worse, a GUI tool?
I placed an order for new fans and plan to test them today.
I haven't adjusted the overclock yet; it's currently running at 4ghz.
I misunderstood that earlier. The reading should be accurate. 30C would be average, but possibly too high when idle. 30-50C seems normal for nominal to moderate load. 75C would be unusually high for a stock CPU unless you were using Prime or something similar, and even then, I’d guess around mid 60s C.
Is the pump outlet connected to your CPU block or the reservoir shown in the photo? It shouldn’t matter much, but it’s better to direct coolant to your block. Also, on the pump top, could you verify that the inlet/outlet ports are correctly labeled?
What’s your typical room temperature like? Do your temperatures remain steady or do they rise gradually over time?
Can't rely on water or big coolers to maintain temperatures below 5 to 10 degrees above ambient. They perform better under heavy loads than smaller ones, but air or liquid options aren't as effective at idle. Light load or idle conditions don't accurately reflect cooling performance.
Ambient temperature is around 22C, but reaching up to 50C during idle seems incorrect. (And 75C under load, which would have increased more if I hadn't stopped the test).
My configuration is: reservoir → pump → cpu → radiator → reservoir. The inlets and outlets are labeled on the pump, so I'm confident in the connection. I'm not fully certain about the pump's orientation, as it isn't specified in the manual.
The order is correct. The pump should be positioned below the reservoir's bottom, with the inlet at the top of the pump.