View Full Version : Adjusting CPU fan speed
07-09-04, 11:41 AM
My system runs a tad warm. I've seen a few comments regarding fan speeds, and I'm wondering how/if one can manually adjust the fan speed?
With my ASUS motherboard's Probe function I can set it to some sort of "smart" adjustment mode, where the fan will supposedly adjust speeds based on the current temp -- but that never really seems to make much of a difference. I just want to turn it up a little bit...can that be done in the bios?
Here's my fan: http://www.newegg.com/app/viewProductDesc.asp?description=35-106-602&depa=0
That fan only moves 32.4cfm of air, so the easiest thing to do would be just to replace the fan with a faster model. Your fan is 80x80x25, so this fan (http://www.newegg.com/app/ViewProductDesc.asp?description=11-999-107&depa=0) moves a bit more air (37cfm) and at under 3000 rpm it should still be decently quiet.
07-09-04, 01:56 PM
That is done by limiting the fan when it's not needed. It can only turn it down, not up.
The fan is designed to run off 12V. Either through a potentiometer (a variable resistor, like a light dimmer) or through a thermistor (a thermally-sensitive resistor), the electricity going to the fan is limited. So when you turn the knob down or your system is cool enough, the fan slows down. Ruccus has linked to a "7V mod" before - you use a resistor to cut the electricity almost in half, which slows your fan down and makes it quieter.
If your system is too hot for the fan to handle, the fan will always run at max speed. It will never get cool enough to slow the fan down.
There's no way to get more than 12V to your fan, without transformers and stuff to change the electrical signal. Either your fan and/or controller are broken, so it's not running your fan as fast as it should be, or the fan just isn't enough for your system and you need to upgrade. I think I recall hearing that the Tr2tt is a relatively poor cooler when I was looking to upgrade. Might want to compare its CFM to other 80mm fans...
07-09-04, 04:02 PM
My computer, for some reason, has pretty much always run in the low 50s -- and actually, a few months ago, in the low 60s.
In the last few months I have bought: the cpu fan (heatsink?) that I linked to above; Raidmax (http://www.newegg.com/app/viewProductDesc.asp?description=11-156-133&depa=0) case; and replaced three of the 80mm fans on it with thisCoolerMaster (http://www.newegg.com/app/viewProductDesc.asp?description=11-999-051&depa=0).
Now, it's fairly comfortably in the low to mid 50s (at the hottest part of the day). And although I never crash and it doesn't seem to be adversely affecting performance, those numbers just kind of worry me. Oh, and my CPU is a 1.3mhz athlon, 133 bus, from about three years ago -- I can't remember my motherboard, and I'm not at home right now. (Yeah, I realize I totally need to upgrade. the system still works fine on all the games I play -- which isn't much, warcraft 3 mostly, but I just broke up with my long-time g/f, the one who made is so I never played computer games, and so now I'm jumping back onto the game train and will, in a few months or so, upgrade).
Ruccus, the fan you linked to is a case fan -- not something I can put on my cpu (unless I am completely missing something here).
I think I just probably need to accept my current temp numbers and hope for something better when I upgrade. If I was freezing up, then I'd definitely be worried, but I'm not.
Your heatsink is comprised of three parts; the base, the fan, and the fan guard. You can replace the fan with any fan that will fit the current fan's dimensions (80x80x25) and will plug into the motherboard's CPU plug (meaning it has to have a three pin connector).
The fan I linked to is a standard 80x80x25mm fan, useable as either a case fan or processor fan, so long as the heatsink will support it. Just unscrew the screws holding the current fan and fan guard to the heatsink, replace with the new fan (make sure it's put in the right direction so that the air is blowing down - there should be an arrow on the housing telling you air flow direction), then use the screws to secure the fan guard and new fan to the heatsink.
07-09-04, 05:38 PM
Good to know. Thank you.
I swear, I sit around and do all this research, and there are always little things that I miss. so much to learn.... and retain.....
07-10-04, 08:18 AM
I did the same thing as Ruccus is recommending. My fan was in the process of dying, but it was on a good Alpha heatsink. I just bought a new fan (mine is 60mm, not 80mm) and swapped it. Most of the new stuff didn't seem to be as good as the Alpha, which I bought with my T-bird 850 (even older than yours). Alpha PAL6035 (http://www.thetechzone.com/reviews/cooler/alpha/pal6035/index.shtml) and Vantec ThermoFlow 60mm (http://www.newegg.com/app/ViewProductDesc.asp?description=11-999-615&depa=1) are what I have...
If in interests you, you may be able to drop a faster Athlon XP into your system with no other changes. I have a 2400+ in mine right now, though it's slightly underclocked because my motherboard doesn't want to show the higher multipliers. It's only supposed to support up to 1.4GHz, and not the XP.
You may be at the point where you don't want to put any more money into an old system, but if not, a drop-in CPU upgrade might be a relatively cheap way to get a decent bit more out of your system.
07-10-04, 10:59 AM
When I bought this system, as a relatively poor college student with a waning everquest habit, I naively tried to convince myself that it would be the last system I would ever need to buy (primary because I just don't really like spending gobs of money on computers). But now I'm a graduate with disposable income, and World of Warcraft is looking mighty tempting.
I'll probably wait and see how my system runs WoW, and then decide from there if I would want to drop a new cpu into my mb, or just buy a new mb and cpu -- and possibly a new video card. I really have no idea how my 64mb geforce3 matches up to current cards; or more importantly, how it will match up to current games. Most of my current components could be swapped into a new mb/cpu set-up -- except for the 512mb, 164-pin stick I bought a few months ago, since I don't think any new pc motherboards support 164-pin.
I guess I'll seriously start thinking about the upgrade once I really notice my computer bogging down. At least it's nice to know that if I take good care of my computer it can last me 3+ years without any noticable slow-down.
Also -- back to Temp. -- this cpu has always run warm. I'm on my third heatsink right now (I replaced the first one after it started heating up so much while playing EQ that the computer would freeze), and I have tons of air flowing inside and it still sticks to the 50s. Perhaps it's just my specific cpu's personality -- and perhaps I should just accept that, and maybe give it a little hug to let it know that I will always think kindly of it, as long as it doesn't start screwing up on me again.
What compound did you use to attach the heatsinks?
Seems odd that it would continue to run hot after you've tried so many times to cool it down.
07-12-04, 12:02 PM
I used Arctic Silver 5.
I mean, I've seen some improvement after all the modifications I've made. I used to be around 62 or 63. And if I had the computer on during the day, when it's warm (although it rarely gets above 80 where I am), it would sometimes make a loud, relentless BEEP, which of course I gathered was a warning of some sort and would then quickly turn the computer off and then wait until the evil sun set before turning it back on.
Right now it's at 55. oops, 56 now. I wonder how warm my apartment is? I'm moving in a week to a new place, and I'll see if the new environment makes a difference. And I won't put the box in a corner (albeit pulled out from the corner right now, to allow some more air flow).
07-13-04, 02:04 PM
I think I've come up with a few things I can do. One is to take a closer look at my wires and see if I can free up some space in there for air to move around.
And the second (which I think will be more substantial) is to reverse my side fan so that it is intaking air rather that dispelling it. I've realized that I should be equalizing the air flow a little more. That probably should have been obvious to me a while ago.
I wonder if I should have my front fan intake air, as well? And then just have the two back fans releasing air.
You have all your fans expelling air? No wonder you're overheating. If you've got every fan expelling air you're creating a negative zone inside your case where air doesn't move, it just stagnates. The fans won't actually move the air because the negative pressure inside the case will suck the air back through the open spaces (namely between the fan blades which are trying to move the air in the other direction).
The front fan sucks in air and the back fan expels air, to move air in the proper 'S' shape through the case. only when air is moved both into and out of the case is proper cooling accomplished. The front bottom fan always sucks in air, and the top rear always expels air.
07-13-04, 09:25 PM
I'm not exactly sure if my front fan was expelling air. I didn't change anything with it, so I'm assuming not. But still, I think I had too much of a nego environment in there.
And when I replaced my case's stock fans I didn't replace the front one -- but I'm going to do that now.
07-14-04, 07:26 AM
Take a look at the zalman heatsinking products. There have a few products that are good and don't sound like you have an airport running in your box