How ACCURATE are the readings on Speed Fan, they differ from those in BIOS

[blinky88]

I've just installed speed fan to monitor temp's, I would appreciate comments from members about its accuracy.

[poisondeathray]

In my experience no software monitoring is accurate, and chip sensors can be off by quite a bit or stuck. So it can vary by chip as well. A digital laser thermometer will be the most accurate, if you average the readings from several measuring points.

The most important thing is to look at the trends. e.g. If it's consistently +5 from your laser reading in some software program , then keep that in the back of your mind. If speedfan is consistently +5 from the bios reading then keep that in mind. So if you were running "x" degrees at load (you could use prime95, occt, linx, several others... to load your cpu), but with the same monitoring program you somehow shoot up a few degrees with the same ambient temp conditions, this would suggest a problem.

You can cross reference with a few software programs eg. everest, realtemp, coretemp. Realtemp is probably the most consistent one once calibrated.

[Krispy Kritter]

Most apps such as Speed Fan can vary their readings based on app version and the BIOS version installed. So I wouldn't put a lot of faith in their accuracy. For the most part, you don't really need them to be totally accurate. Their purpose is to provide you a baseline so you can notice any increases (or decreases).

[redwudz]

Usually the BIOS is the most accurate, second would probably be a temp monitoring program from the motherboard manufacturer. And BIOS temps won't usually be the same as when the OS is loaded and fan controller programs are running.

As mentioned, the trends are the most important. How fast does it warm up under load, how fast does it cool down when the load is removed? That will give you an idea of how efficiently your system is removing and dealing with the heat. This applies both to the CPU and the case temps. Case temps are measured from a motherboard sensor, so those are not really the air temps within the case. I use a infrared thermometer and it will usually show lower temps as you are measuring the temps on surface of the heat sinks. But it's still very useful.

And check the exhaust temps of the case exhaust fan and the PS fan. That can give you some idea how much heat is being removed.

I use HWMonitor: http://www.cpuid.com/hwmonitor.php I don't feel that it reads the core temps correctly, but it's fast and easy to use and provides other information. Some temperature programs may be more accurate, but require a fair amount of 'fine tuning' to set up.

If you think you have a problem with excess heat, pull off the case side cover. Run a desktop fan into there if you like. If your temps drop a fair amount, then you might look into your case cooling. Often in a well cooled system, the temps will go up when the side cover is removed as you are disrupting the internal airflow that carries away heat. I've gotten better cooling with some cases by plugging all air intakes except through the fans. Those side and rear vent holes were a problem, not a help, with cooling.

[blinky88]

G'day Redwudz,

I have just completed installing a new MSI PE motherboard in my wife's machine with a P4 3GHz Northwood chip. The BOIS is 20 degrees hotter than what Speedfan says. BIOS 60 deg. 67 under load, speedfan 40 deg. 45 under load. I thought 60/67 was a bit high and would like to think Speedfan is more accurate.

My builds have always been:
120mm intake low in the case, side panels intake blocked and the PSU fan is the exhaust. I have just installed a Corsair PSU with 120mm fan. This fan setup has always produced excellent cooling results, of course I did expect the 3G CPU to run hotter ..but.. I didn't expect 60/67.

The new build is running fine, the temps are not causing any known problems, that said, I'm just feel a little uncomforable with 60/67.

Poisondeathray, thank you for your response and the link, I will have a look at what cpuid has to say.

[blinky88]

G'day Redwudz,

I have just completed installing a new MSI PE motherboard in my wife's machine with a P4 3GHz Northwood chip. The BOIS is 20 degrees hotter than what Speedfan says. BIOS 60 deg. 67 under load, speedfan 40 deg. 45 under load. I thought 60/67 was a bit high and would like to think Speedfan is more accurate.

My builds have always been:
120mm intake low in the case, side panels intake blocked and the PSU fan is the exhaust. I have just installed a Corsair PSU with 120mm fan. This fan setup has always produced excellent cooling results, of course I did expect the 3G CPU to run hotter ..but.. I didn't expect 60/67.

The new build is running fine, the temps are not causing any known problems, that said, I'm just feel a little uncomfortable with 60/67.

Redwudz, I have just downloaded the program you recommended and to my surprise is showing temps below Speedfan, I hope your assessment is correct.

Thank to all members who responded, appreciated.

Cheers to all from downunder.

[blinky88]

Hi Redwudz,

I would like to amend an earlier statement, the program you suggested is showing the same temps as Speedfan.

I hope they are a true indication of the temps.

Cheers.

[redwudz]

They show the sensor temps, if the sensor is reporting it correctly and the temp program is interpreting it correctly. The temps at the surface of the heatsink should be a lot lower. Easy test, put the tip of your finger as low as you can get on the CPU heatsink when it's under load. 60C will make you move it pretty quickly. If your HS is more like 25C - 30C, it should be a lot more comfortable. If you burn your finger, then you usually need better cooling.

Personally, I wouldn't use the PS fan for a main exhaust fan. Better to have a separate exhaust fan opposite the CPU exhaust air. PS fans are generally just to cool the PS, not pull out excess case heat. If they aren't thermal controlled, they may end up overheating your PS because they are only rated for the PS cooling and can run at a somewhat slow/quiet constant RPM, ignoring the internal temps.

Most CPUs begin to have problems around 70C. Much above that and the MB may lower the multiplier and reduce performance to protect the CPU or it may shut down the computer completely. Most times in the BIOS settings, you can turn off thermal control and run the CPU fan at full RPM. It will be a bit louder, but if you need the cooling, an easy adjustment. Even constant use at 65C can shorten the life of your thermal compound and dry it out, necessitating re-coating.

I run my encoder PC with the fan control off and it drops the CPU temps about 5C over the quieter BIOS controlled settings. It runs about 56C max after a couple hours of MKV encoding using all four cores at 100%. But the base of the CPU heatsink is relatively cool, so I don't think the CPU itself is running that warm. And if your internal case temps are above ~40C, your CPU cooler will have a harder time dissipating the heat into the case air.