Correct CPU Fan Speed? 2

[onebigdog]

Does anyone know what the correct (accepted) fan speed on a P4 2.8ghz is to propely cool the CPU? I have a P4C800 deluxe and Asus Probe reports the cpu fan speed at 2400. The reason I ask is that for some unknow reason, my cpu now idles at 55c. It use to idle at 38c. I have 3 case fans, one of which is on the side of the tower that is directing outside air directly into the area of the cpu. My cpu is overclocked from 2.8 to 3.08ghz. and has been that way for 2 years.
If this is the proper fan speed, any ideas why all of a sudden, the cpu is running hotter?
onebigdog

 

[paparazi]

onebigdog
2years! likely the heatsink is all blocked up with dust/debri.
Martin

We like members to GIVE and not just TAKE.
Participate and help others.

 

[onebigdog]

Thanks,
But I had made sure the heatsink was clean. I decided to take the heatsink off. What I found was that the old heatsink paste had become old and crusty. I cleaned the cpu and the heatsink and reapplied heatsink compound and the temp dropped 13 degrees! I never thought that heatsink compound would get old.
Now for the rest of the story...
The reason I was even checking out the cpu temps was because of a strange phenomenon that just started with the cpu. I happened to open SisSandra and saw that the CPU was running at 1.5ghz not 3.0ghz??? I then rebooted into the Bios and the bios was also reporting the cpu was running at 1.5ghz. Not knowing what to do, I just turned the computer off for the night and the next day it was back at 3.0ghz. It has done this several times now. Sometimes, by simply rebooting it will return to the correct speed, sometimes it takes an all night shutdown for it to return. Any ideas????

 

[paparazi]

onebigdog
Well it sounds like the front side bus settings are defaulting back to basic settings so effectively taking the clock speed down.
This normally is a one way ticket ie: does not revert back unless reset in the bios.
The normal course is a failing lithium button battery and should be automatically changed as first suspect (they only cost $3/$4 and generally need changing every 2/5 years anyway.
Also check for capacitor leakage or bulging, which can lead to all sorts of weiredness.

See:

http://www.badcaps.com

For an explaination of what to look for.

Martin

We like members to GIVE and not just TAKE.
Participate and help others.

 

[onebigdog]

Interesting thought...I will check it out as well as the badcaps.com site. By the way, when I wrote the above, the system was running at 1.5ghz even though I reapplied the heatsink compound and got the temps down. I then turned the system off for an hour and when I turned it on to check this site, it was back at 3.1ghz, but the temps were also back to 58 degrees celsius?!?!?. Yikes...what a crazy system.

 

[garebo]

Also, you can now get those coin batteries at the dollar store. I have used a few and they seem to be as good and the same as the $5 ones.

Good advice + great people = tek-tips

 

[micker377]

I know that Intel CPU's will slow down when hot. I've never read of anyone "following" a heat problem to a BIOS screen to see if this slowdown resets the FSB. Have you tried to run at default 2.8 to see if the problem still occurs? It's also possible that overclocking has damaged the CPU.

 

[onebigdog]

This is getting more bizarre...I now realize that the reason that the CPU temps dropped was NOT because of new thermal compound, but because when I booted up, the system was running at half speed (1.5ghz). That is why the temps dropped. Obviously, my first thought was that maybe the Intel cpu slowed down because of excess heat, but how could that be since it was off for a while, as I cleaned the cpu and heatsink to re-apply the thermal compound(the cpu was not hot to the touch). However, if I leave the system off for an hour before booting, it then will boot to the correct cpu speed and runs all day long at 60 degrees Celsius at idle, (it use to idle at 34 to 40 degrees Celsius) but doesn't seem to rise that much further, under load! I even did this with the case opened. Placing a small house fan toward the cpu and motherboard only drops the temps a little.
I though that maybe it is just a bad cpu sensor, but running some real world test confirms that the speed is significantly slower when it boots at 1.5 instead of 3.0ghz. I thought that maybe it is the cpu fan, but it seems to be running at approx. 2400 rpms constantly. I assume that is the correct speed for proper cooling.
Do any of you really think that it could be nothing more than a bad battery???? Has anyone seen anything from Asus or Intel related to this crazy speed thing?
I could understand it better if the cpu dropped in speed when it was hot, but since it seems to drop in speed when you boot up sometimes, that kind of shoots that theory.
I'm starting to loose it...anyone seen this before?

 

[onebigdog]

To answer the question...Have you tried to run at default 2.8 to see if the problem still occurs?
The answer is yes. If I try to reset to 2.8, it may boot at 1.4 unless I turn it off for an hour,like above.

 

[JimInKS]

I am not sure exactly how this works, but in the BIOS, power settings you can enable Advanced Power Management.

One of the settings is Throttle Slow Clock Ratio which, I believe, defaults to 50%.

You might investigate this and try disabling it if it is enabled. My understanding is that this is separate from the built-in thermal protection trottling mechanism that is "hard wired" and kicks in at about 70deg C.

 

[onebigdog]

Thanks for the tip...I did disable it. But even if it were enabled, one of the questions I have is why is the cpu now running so much hotter than before this all started happening? As I sit here writing this, the cpu is idling at 60degrees! Also, it doesn't appear that high temps has anything to do with the throttling back of the cpu. Remember, I had turned the computer off and re-applied the termal past only to see the cpu running at 1/2 speed when I rebooted. Strange!
onebigdog

 

[JimInKS]

With APM disabled is the cpu still running at half speed?

My guess was that you have some kind of thermal problem and the APM is throttling the cpu to try and keep the temps down. This is purely speculation on my part.

Can you determine if the cpu heat sink is really 60deg C?
Ground yourself to the chasis first, and then carefully touch the heatsink, being careful not to burn yourself. If the heatsink is relatively cool, then the cpu is not making good thermal contact to the heatsink.

One last thought you might check if the heatsink is hot.

Is it possible the cpu is running overvoltage for some reason? Does the bios voltage monitor show all voltages in spec?

 

[JimInKS]

One other thought.

Have you reset the bios to factory default?

 

[onebigdog]

Heatsink is hot...
Probe says that the following about voltage:

+12v running at 11.916
+5v running at 4.945
+3.3 running at 30248
vcore running at 1.488

It is running steady at 3078mhz with a idle temp of 60degrees celsius.
If I set back to factory 2.8ghz, idle temp drops very little.
It is hard to say when the cpu throttles back...for example, I have been on the computer all day with temps reaching 68 and still runs at 3078mhz. There doesn't seem to be a pattern. As I said above, the last time I took the heatsink and cpu out to clean and re-apply thermal past, (it was cool at that point) it booted up at 1/2 speed. Even after several reboots, it was still running at half speed. I usually have to then turn off the computer for 40 min or longer, then reboot and speed is back, but with these high temps.
Do you know what the correct heatsink fan speed is suppose to be? My Intel heatsink fan is running at 2400rpms. If I place a small house fan directed at the computer with the side off, the temps will usually drop by 5 or 6 degrees to around 54 to 55 degrees celsius at idle, no where near the 39 to 44 degrees it use to idle at. Stumped.

 

[JimInKS]

I have a Asus P4P800 deluxe mb with a 2.6GHz P4 cpu.
The cpu has the retail Intel cooling setup.
I am running the board 10% overclocked.

My readings are:
CPU temp 48 ( I need to clean the HS, normally runs a little cooler)
MB Temp 39
CPU fan 2360
Power Fan 1770

+12V 12.099
+5V 5.053
+3.3 3.328
Vcore 1.568

Your system looks real similar to mine.

Does task manager show that the cpu is idling? Is it possible you have a software issue that is causing the cpu to run at 100% all the time?

 

[onebigdog]

I had thought that early on and was one of the first things I checked...thinking that somehow a virus or spamware was involved, but cpu usage is between 0 and 1% at idle.

 

[jurgen36]

I do believe your Vcore is much to high. Have the ASUS p4p800E deluxe bord with a P4 3.4E "Prescot" processor, idles at 47C, 100% load 63C, outside temp, 40C bord temp 45C, using 10 chassis fans and 4 PSU fans. The Vcore votage is only 1.285 volts. The maximum voltage for the cpu as specified by Intel is 1.5 volts. This is an absolute maximum. Any higher voltage can and will dammage the cpu.
Regards

Jurgen

 

[onebigdog]

Jurgen,
I don't doubt your advise, but why then does Probe (the Asus utility) say that the VCore voltage is OK even at 1.52 volts?
And since I have a 2.8ghz P4 on a deluxe board (not deluxe E) does that change the vcore requirements to a higher number?
obd

 

[JimInKS]

The P4 'Northwood' core has a default voltage of 1.5V.

I am currently out of ideas. Hope some of the more experienced members can join the conversation.

 

[onebigdog]

Thanks JimInks for the info...I checked the bio settings for Vcore. Its manual settings would not go below 1.5v so it confirmed what you just said.
In an earlier post Paparazi suggested the motherboard battery could be the culprit...has anyone ever experienced my problem because of the battery? I would replace it in a heartbeat (it is cheap), just to see, except it is in a bad location to get to, without taking a lot of stuff out first.
obd