Need new fan but can't measure temp! help

Shane™

I have myself a very loud fan, and I'm looking to replace it.

Simple I hear you say, get the mobo temp and... eh wait I have a Dell 8300 and it has no means of measuring the temp.

So this is my problem, I have one fan, an 80mm case fan, and it is aimed (redirected) at a massive headsink on the processor. But I cannot measure the temp, I'm not going to overclock it, I just want to cool it.

So can anyone tell me how to calculate the required CFM?

I have a p4 @ 3GHz.

Thanks for any help

Nukem

i dunno what ya want that for but measuring the temp manually get a heat gauge bout 5-15euro if you find it -looks like a small alarm clock.
Try mobo monitor - will get temps for that dont know about fan speed (just check it supports your mobo)
MMMM....... Bios might have a settings for there fans,did ya try that.
Anything short of getting a fan controller - im outta ideas.

TacT

play some games for a few mins or run prime or something stressful, touch base of heatsink with the tip of your finger, is it warm/hot/burning? If no - overclock, if yes - no overclock

Shane™

Nukem wrote:

MMMM....... Bios might have a settings for there fans,did ya try that.

Yeah tried the bios, flashed it to the latest version, but I don't care about measuring the temp.

Does anyone know how much airflow I would need?

Would a 30 CFM fan cool it? could I risk a 20 CFM fan? or because it's the only fan and thus the only means of cooling the processor, should I go for 40 CFM or even 50 CFM?

Tact the fan I have is fine for cooling, it's just loud.

Was looking at this
but i'm not sure if it's strong enough.

Also has anyone ever used HiTide? are they safe?

Thanks again

CombatCow

Yea i use HiTide a good bit, they have good fast shipping. What about an adjustable fan here :

http://www.hitide.ie/catalog/product_info.php/cPath/21_23_41/products_id/129

you can ''sometimes'' roughly work out the cfm for a fan by the ammount of noise it makes,ya see the fan stats, the cfm and dB is almost the same.

Air Flow 26.87 CFM---33.23 CFM---36.76 CFM---39.8 CFM
Noise.....26.50 dB

---

29.80 dB

---

30.10 dB----38.00 dB


30 dB would be a tolerable noise level for a fan in standard cases.


CC

Shane™

Dell disables both in BIOS and in design of their custom Intel motherboards the ability to "tweek" or "overclock" the CPU voltages. Along with this, accessibility to CPU temp is disabled. They do this for obvious reasons -- they are making conservatively rated systems for business users. Since they warrantee the products, they do not want to be replacing roasted CPU's that have been overclocked. Thus, on a Dell mobo their is not way of doing this. Unless you are into overclocking and running the CPU up to the threshhold of "melt down", there is not much reason to worry about the temp. Dell has designed the system to stay well within operating tolerance.

Source

Thanks CC, I think I'll get that fan you suggested.

I think i'll get a tempature probe, wonder why Dell really do this

omathuna

You could try running the fan at 7 volts rather than 12V. It reduces the noise and CFM's.
You would need to watch the temperature if you do this.

See this site. about half way down the page.
http://www.7volts.com/quiet.htm

Quote....
How do you get 7 volts out of the 12 and 5 volts supplied by the Yellow Black Black Red Molex connector you ask?
You use the yellow 12v wire as the power connector to the fan and use the red 5v connector as the fan ground. The fan sees the potential difference between the 12v and the 5v so is run at 7 volts.

Shane™

omathuna wrote:

You could try running the fan at 7 volts rather than 12V. It reduces the noise and CFM's.

Don't think I can afford to drop CFM's

omathuna wrote:

You would need to watch the temperature if you do this.

Can't watch the temp.

Pity I bought a Dell
Good link though

fiacha

a quick google suggests that te dell 8300 cpu fan speed it temp controlled. have you tried installing speedfan or mbm5 to see if they can pick up a temp sensor ??

there are a load of active threads about quite cooling fans on the overclockers.co.uk forums here

improving the case airflow may allow you to use a lower rated fan on the heatsink without increasing CPU temps.

good luck.

Shane™

fiacha wrote:

a quick google suggests that te dell 8300 cpu fan speed it temp controlled. have you tried installing speedfan or mbm5 to see if they can pick up a temp sensor ??

Tried these before but just to be sure tried them again, and no Dell 8300 does not have an on-board temp sensor that can be accessed from the OS

Before I tried a Dell tool which was supposed to hook up the temp sensor, but that didn't work either, I've given up on checking the temp.

So does anyone know about how many CFM will cool a 3Gig processor?

heffo9

i have a dell 4600,i downloaded a program called 'cpucool',
this program gives you all the info related to your computer, it even gives you the internal temperatures of your mobo,ram etc.
check it out at
www.podien.de
they also have software for overclocking the fsb. but as you know with dell computers , this feature is locked in mobo bios.

Shane™

heffo9 wrote:

i have a dell 4600,

This is supported by loads of motherboard monitors (lucky b*s*r*d)

heffo9 wrote:

But as you know with dell computers , this feature is locked in mobo bios.

Yeah there is loads locked in my mobo bios, as EVERYTHING.

Any one know if you can use a no-Dell bios to access the temp sensor, btw there's a sensor in there as the fan is supposed to be controled.

How does this work? will it increase the voltage if it's too hot? like a termostat!

fiacha

Shane&#8482 wrote:

Tried these before but just to be sure tried them again, and no Dell 8300 does not have an on-board temp sensor that can be accessed from the OS

Before I tried a Dell tool which was supposed to hook up the temp sensor, but that didn't work either, I've given up on checking the temp.

So does anyone know about how many CFM will cool a 3Gig processor?

don't think it's as simple as that. the CFM needed to keep your cpu temps down will depend on the case temp, the performance of the heatsink and thermal compund etc.
the only reliable way to measure how affective your cooling, is to monitor the temps.

was speedfan able to detect the FAN speed from the mobo ? If so, you can just manually adjust the fan speed depending on what you're doing. 100% for gaming, 60% for browsing etc. the fan at lower RPMs may be more acceptable.

as nukem said, pick up a cheap temp probe as use that to measure the temp at the base of the heatsink. you're core temp will never be any lower than that reading.

another option is to buy a cheap fan like the Sharkoon silent series that comes with an RPM controller. you can then play around with the speeds. i think that Peats still stock these.

Shane™

No joy fiacha with fan control, speedfan could only work with the hard drive.

Think you have the solution, just need a cheap probe now.