Changing a Computer Fan's Speed

AnteCantelope

My computer makes a ton of noise, even while idling, so I thought I'd take a look at the fans and see if they could be slowed down at all. I used SpeedFan, and that's telling me that I have 5 fans, 4 of which are doing nothing, and one which is going at 850RPM. Since the CPU core speed is around 30 degrees I figure I could safely lower the fan speed, but I don't know whether Fan 1 is the CPU fan or something else, and whatever fan it is I'm not sure how to change it.

I think SpeedFan is meant to be able to change the fan speed, but I'm not seeing that option anywhere so maybe I should use something else?

Also, 4 fans not running at all? Is it possible that SpeedFan isn't reading them right?

rfalias

Have you blasted it with canned air yet?
Dust makes my fans sound like a jet taking off, I have to dust them to get them to shut the hell up.
Some fans may not be variable speed as well.

AnteCantelope

rfalias wrote: »

Have you blasted it with canned air yet?
Dust makes my fans sound like a jet taking off, I have to dust them to get them to shut the hell up.
Some fans may not be variable speed as well.

It's sounded like this for all of its life, and I've cleaned it out a few times.

I know that when I bought it (because I custom-picked the parts, but didn't build it myself) that there are two variable-speed fans in there, which are temperature controlled, but everything else is stock, including CPU fan, so if you know what comes stock with an Antec900 and an Intel Core2Duo E8500 then you know more than me.

rfalias

So do you know if its the case fans or the CPU fan?

1 x 120mm TriCool rear fan with 3-speed switch control
2 x 120mm TriCool blue LED front fans with 3-speed switch control to cool HDDs
Is what's in the case, you would have to pull the side off and try different switch settings.

The fan should not be that loud from the get go. May look at replacing the problem fan all together.

AnteCantelope

You know, I didn't think it was likely that only one fan was running at all. When I stick my head down there I can definitely tell that most of them are running at more than 0RPM, so I think that FanSpeed has just got it wrong.

I don't know that any one fan is a problem fan, it's just that the computer sounds a little like a desk fan, all the time. Maybe tomorrow morning before I turn it on I'll pull it open and disconnect the two extra fans I had installed? I could try disconnecting one and see if the problem goes away entirely, which will mean it must have been a problem fan.

And where would I find the controls for those 3-speed fans? Will they be inside the case, attached to the fans themselves?

rfalias

Yes, the controls will be somewhere on the line between the case and the fan usually.

I wouldn't just unplug the fans, especially not the CPU fan, as that will prevent it from booting all together.

So is it just like a normal fast wooshing fan sound? Or is it more like its defective, a more mechanical sound?

Edit: also, after some quick research it appears that the case fans (4 of 5) do not send RPM signals, so you would not be able to tell they were anything but on with a program.
The one you saw was likely the CPU fan.

AnteCantelope

rfalias wrote: »

Yes, the controls will be somewhere on the line between the case and the fan usually.

I wouldn't just unplug the fans, especially not the CPU fan, as that will prevent it from booting all together.

So is it just like a normal fast wooshing fan sound? Or is it more like its defective, a more mechanical sound?

Edit: also, after some quick research it appears that the case fans (4 of 5) do not send RPM signals, so you would not be able to tell they were anything but on with a program.
The one you saw was likely the CPU fan.

I'm happy to fiddle a little with my computer, but trust me when I say I won't be pulling out the CPU fan. I was just thinking of pulling out the optional fans I put in, and maybe fiddling with the speeds of the others.

It doesn't really sound defective, although occassionally it gets a really annoying rattle. Usually it just sounds like a normal computer, only much louder. I think that maybe the optional fans, which are meant to change speed depending on temperature, are just permanently stuck on their highest setting. That's just a guess though, because that seems like the easiest thing to go wrong.

rfalias

That's a possibility.
Do you know what add-on fans you got? Perhaps they are not temperature regulated afterall?

AnteCantelope

ANTEC 120MM SMARTCOOL THERMALLY CONTROLLED CASE FAN

I just had a look at the specs, and oh look, minimum speed 980RPM, and it does that at 20 degrees. It seems like two 120mm fans running at 1000RPM constantly might be the problem, right?

EDIT: Their site says that it makes 20dB at 20 degrees, and since my computer seems to be around 30-35 usually they would estimate 24-28dB. With two of them, would that be a significant source of noise? I'm not really sure how loud that is.

rfalias

Yeah, big 120's going fairly fast are going to make it sound like a box fan. You might be able to reduce it by turning one off, as long as it stays cool should be fine, just keep an eye on it when under heavy usage.

AnteCantelope

I thought that the idea of big fans was that they could run slower, making them quieter than small, fast fans. I know that people building PCs specifically to be quiet often mount bigger fans than the case was designed to take.

I think that if I leave all of the stock coolers in it'll be fine for normal use, I'll just stay away from Crysis and the like for now.

rfalias

Even then you should be fine unless you over-clocked it.

I've been using stock fans in mine for ever and always play stuff cranked up. The case it self has been through about 4 generations of complete rebuilds and still keeps up just fine, and they are not even 120mm fans.

AnteCantelope

OK, cool. I put the fans in because I thought some bigger fans might keep temps down, and thus noise down, it may have backfired a bit.
Next time I'm buying the quietest fucking case.

Technicality

Where possible you should try and isolate the main source of the noise, because most of the time its only one of the fans contributing 90% of the racket.

Don't forget you probably have a fan in your PSU, and on your graphics card too. Either of them is a likely culprit for causing an ungodly amount of noise if defective.

BlindZenDriver

AnteCantelope wrote: »

I thought that the idea of big fans was that they could run slower, making them quieter than small, fast fans. I know that people building PCs specifically to be quiet often mount bigger fans than the case was designed to take.

With quality 120 mm fans running at 1000 rpm what you hearing is mostly the air moving and not so much the fans as such. Had there been a smaller fan moving the same amount of air it would be spinning so fast your computer would sound like a hair dryer.

AnteCantelope wrote: »

I think that if I leave all of the stock coolers in it'll be fine for normal use, I'll just stay away from Crysis and the like for now.

It sound to me as if your system is cooled much more than it needs to be. It's likely you can disable some coolers or run them under spec without problems. Many fans will happily run below spec and the important thing is to make sure the start at the low voltage.

Check the temperatures of you motherboard, your graphics card, your CPU and your hard drives and just make sure they are within safe limits what ever you do. If you do that you can start scaling back on cooling. Apart from stopping or slowing fans looking at where comes in and goes out is also worthwhile - there must be a balance so that air moves through the case not all over and some fans must suck while others must blow. I find that blocking some vents with masking tape can be a good way to go in guiding the air.

mcdermott

FYI I use one of these to control my fan speeds. I picked it up on sale for like $16 at Fry's, but expect to pay somewhere around $20 if you look around. It does all five of my fans, and helped a lot.

They have another (more expensive, and larger) one that's a little slicker, but probably overkill. This thing allows me to shut down my GPU intake, dial back my front intakes, and dial back my exhausts without having to crack the case...which is all I want. It's low-tech; just does voltage adjustment across a range (with 5 settings possible for each fan), but it works. Also, you can turn the backlighting off when you aren't adjusting it.

One thing I found is that some of my fans actually make more noise at lower RPM/voltage; there's a "sweet spot" at about 80% where they are quieter than full speed but don't start the rattle/hum of the lower speed.

AnteCantelope

Well, I think I've narrowed it down to the CPU fan. The case fans were already on low (they're TriCools) and are all pretty quiet. I've tried controlling the GPU fan and it turns out I can't even hear a thing unless I turn the fan up a fair bit, while it's idling the fan's at around 30% and it's effectively silent. It may be the PSU, but I'm hoping that it's the CPU fan because that seems easier to deal with.

I'm just using the stock heatsink of an Intel dual core E8500. Aside from getting a new CPU heatsink, is there anything I can do to quiet it down a bit? I was thinking I could turn the case fans up to medium, to keep the inside of the case cooler and then maybe the CPU will slow. I don't really want to underclock the CPU because it's already annoyingly slow, and it's the bottleneck of this PC. Any ideas?

EDIT: The CPU idle temp is around 35 now, I've seen that sometimes it's as high as 45 while just on the net. I'm not sure how hot it gets while under stress.

Midshipman

Turning up the case fans probably won't help the overall sound level from the computer. If your CPU fan is the culprit your best bet is to get a better heatsink/fan combo. Depending on the size/form factor and how it is attached, it is possible that you can find a replacement fan for the current cpu heatsink, but unless the current fan is just really poorly made, you won't get a drastic improvement that way.

AnteCantelope

Midshipman wrote: »

Turning up the case fans probably won't help the overall sound level from the computer. If your CPU fan is the culprit your best bet is to get a better heatsink/fan combo. Depending on the size/form factor and how it is attached, it is possible that you can find a replacement fan for the current cpu heatsink, but unless the current fan is just really poorly made, you won't get a drastic improvement that way.

I was thinking that I could turn up the case fans, then turn down the CPU fan. Would that work?

I need to buy a new computer anyway, so maybe the best option would just be to hurry that process up instead.

Satsumomo

You can find a heatsink for your CPU that is compatible with 775 and whatever you're gonna upgrade to, and use it in the meantime.