Weird problem, temps drop after sleep mode
Weird problem, temps drop after sleep mode
I'm experiencing an unusual issue with my CPU temperatures. When I power up my computer, the idle temperature in the idle state (not core temps) is around 45. After putting the PC to sleep and waking it back on, the idle temperature drops to about 30, and it remains stable even after repeated sleep-wake cycles until a restart occurs.
Some details:
- Motherboard: Abit IP35-E
- Processor: Q6600 G0 @ 2.4GHz (stock speed)
- Cooler: CoolerMaster Hyper TX3
- Monitoring tool: CPUID Hardware Monitor
- Other tools: Speedfan, some unknown program showed varying readings
- Fan control: The motherboard's fan speed adjusts based on this perceived temperature drop
- Core temperatures: Around 38-43, unaffected by sleep mode
- Stress testing: Under load temps rise to about 60 before sleep and drop to 47 afterward, with cores near 57-61 in both cases
I recently replaced the heatsink (previously stock), which might be contributing. I'm not entirely sure if the installation was perfect, but it shouldn't affect sleep mode behavior.
Any clarification on what the correct temperature readings should be would be helpful. I'm also unsure whether the values after or before sleep are accurate. Please share more details about your setup and observations.
Well... the only conclusion I can reach from your words is that the CPU warms up when it starts, putting it under continuous pressure... in contrast, waking from sleep mode takes less time and causes less strain on the CPU because it simply reads restored data from RAM to bring the PC back to its original condition.
Yes, the BIOS fan control system will adjust fan speeds noticeably between startups and when waking up, as the machine detects varying temperature changes in a short period. Don’t worry—fans are designed to change speed frequently.
It's not just about higher temperatures right after startup; they remain elevated even when I let the computer sit idle for hours. I'm also not concerned about the fans. This suggests the issue isn't limited to monitoring tools like HWMonitor or similar software, as the BIOS fan speed control responds to these readings. Essentially, this shouldn't be a problem with the monitoring system.
Yes, I think the OP has a valid concern. It seems the sensors might be malfunctioning, which could cause the software to display incorrect readings. This might affect the system, especially if fans are controlled by them.
Also, the BIOS fan control relies on sensor data from the motherboard, so it could result in the system running fans at incorrect speeds depending on temperature.
This suggests the sensors may be faulty.
I recommend reinstalling the new heatsink you just installed. Clean both surfaces thoroughly and apply fresh thermal paste, such as AS.
Be extra careful this time, following the advice that "Practise makes perfect." It’s better to double-check before proceeding, in case something went wrong earlier.
It would also help to compare the temperature differences before and after installing the new heatsink.
Yes, I'm thinking about reseating it just to double-check (I really dislike the idea, the heatsink was a hassle to attach so I haven't managed to fix it yet). But I don't have the previous temperature data for two reasons: A) I was using Speedfan back then and didn't realize it was lowering temperatures by about 10 degrees compared to HWMonitor, and B) I hadn't noticed the strange sleep mode behavior, so I only monitored core temperatures. Now that I'm using Speedfan again and comparing, I see that idle core temps stayed almost unchanged before and after the new hardware, while load cores dropped around 5 degrees. I'm still confused about how sleep mode connects to the sensors on the motherboard.
Maybe, just a guess, when you turn on the computer from scratch, every component of that specific motherboard and its PSU can get a fresh start and receive perfect power for all parts. But once it enters a passive state, switching to a low-power mode of the PSU and turning on the motherboard only to maintain data in RAM and Pagefile, when the system comes back to life, it might take some time for the switch from passive power to maximum PSU output. This could result in lower temperatures on the sensors because they may not have received the full boost they need.
Hello Margse, I'm experiencing the same problem with temperatures—higher and steady after startup, around 42°C, but when I power off and come back on, they drop to a lower, stable 30°C during idle. This is with my AMD Phenom II X4 965 Black Edition. I was wondering if you've found a solution or how to handle it. TY.
Hey, I was thinking about switching the Power Profile in the BIOS to the alternative version. From what I know about those Wake Up/Sleep modes, one uses a steady current of 5 AMP even when the system is off, while the other only uses 1 AMP. That could really make a big difference.
I just thought about it, have you considered altering the Power Profile in the BIOS to a different setting? From what I understand from those Wake Up/Sleep modes, one has a steady current of 5 AMP even when the system is off, while the other only uses 1AMP. That could really make a difference.
Hi alyoshka, this approach seemed quite effective. My BIOS offered two choices for the ACPI sleep mode level—S1 and S3. I changed from S3 to S1 and the issue vanished. I didn’t want to stick with S1, so I reverted it and the problem returned, but I hope someone familiar with the various sleep modes can help figure this out.
Another curious occurrence happened when I put the PC to sleep using the standard S3 mode. It entered sleep but didn’t wake up properly—fans ran but there was no visible recovery, no video output, no input signals. I pressed the power button to shut it down and then restarted it from sleep. It resumed as if nothing had occurred. This isn’t unusual; it happens occasionally for some reason, but what’s notable is that after that, temperatures didn’t drop as they usually do after entering sleep mode.
cocopuff, as you can see, I haven’t found a solution yet and had to give up before your responses. If you have any suggestions, please share. Do you have the same motherboard, and could you let me know your BIOS version?
EDIT: I should also note that I’ve repositioned the heatsink recently and there were no significant temperature changes afterward.
EDIT2: After reminding you about this issue, I performed another small test—trying hibernation. It didn’t produce the same kind of temperature fluctuations.