On Thu, Aug 28, 2003 at 07:00:37AM +0200, Roberto Sanchez wrote: > --- Alvin Oga <aoga@ns.Linux-Consulting.com> escribi?: > > > > On Thu, 28 Aug 2003, [iso-8859-1] Roberto Sanchez wrote: > > > > > > On the other hand, my 1GHz Athlon plays FPS games well, but sounds > > > > like a Boeing 737 is parked 2.5m from my head. > > > > ... > > > > > Hey, consider yourself lucky. I have an AMD 2500 XP+ (1.83 GHz) that > > > sounds like a 747 @ 1m :-) > > > > the cpu doesn't make any noise :-) ( sorry couldn't resist ) It makes LOTS of noise... try listening to an AM radio placed anywhere near the PC... it just doesn't make any sound :-) > > - sharpen the leading edge of the fan blades > > Hadn't heard that one. I'll probably give it a shot. Make that the trailing edge... have a look at a pigeon's wing, or a 747 if that's easier. The leading edge is blunt; it's easy to part the air without causing turbulence. The maximum thickness is fairly near the front, and then there is a gentle taper to the sharp trailing edge; getting the air to come back together again without turbulence is much harder. Turbulence creates drag, and also noise. > > - if you do close up all the little noisy holes > > and seems, make sure you have a big/giant hole someplace > > ( like leave a cdrom drive bay open or side cover off ) > > Actually, I have heard that this is not advisable (at least leaving a side > cover off). I was told by a friend who keeps pretty well up to speed on > hardware that leaving a side cover off actually degrades the fan's ability > to move air across the CPU/heatsink. Something about a sort of small scale > wind tunnel effect. As far as heatsinks with individual fans are concerned, their performance is most unlikely to be noticeably affected. It may however allow 'stagnant' pockets to form and thereby cause items located in such pockets to run hotter. That may be the effect your friend was referring to. Having said that, I have a friend whose 1.2GHz system with 2 hard drives all assembled properly by the shop had case temperatures almost too hot to touch; since he took the side off and put the hard drives loose on top of the case (so he could swap the cables to work around Windoze bugs) this is no longer true, and nothing inside the case is that hot either. I tend to leave sides off (see below) and occasionally stick my hand in and feel things; nothing gets unduly hot except disk drives, which IMO always need fans anyway. Running with the sides off often reduces noise from the PSU fan, as it is drawing in cooler air, and the better PSUs will recognise that a slower fan speed will suffice and slow it down accordingly. > > - air moving thru small holes and seams is what makes the noise > > - make giant holes ( the size of the fan ) and close > > all seams and all holes smaller than the fan size w/ tape > > > > If I could cut big holes where the fans are I would. But, man that would look > ugly. You should see what I've got... One box has six hard drives, one of which is outside the case entirely, along with much of the length of two SCSI ribbon cables and a tree of power splitters. A fan is fixed to the front with blue insulating tape and string, blowing over two hard drives; another fan is attached to a nozzle made from a toilet roll core, to blow air down the slot between expansion cards over the graphics card heatsink. Next to it is a box with ten hard drives; again the cables hang out of the side, because the box stands on four of the hard drives and a second power supply for those drives. The case has no plastic front either, because it was a silly bulgy front that made it hard to get to the floppy drive. Short circuits between the hard drives are prevented by interposing folded sheets of newspaper. Both boxes are covered in balloons as a pigeon deterrent. My solution to the fan noise problem is to run fans off 5V instead of 12V, or alternatively run them off 12V via a series resistor of around 150 +/- 50 ohms - some fans prefer one method over the other, depending on whether the brushless drive circuit is more desirous of voltage or current when starting. They then run slowly enough to be silent, and I can stick fans on anything that's running a bit hot without making it any noisier. (Though with all those hard drives, it still whirs a fair bit...) (I leave the CPU fan alone; it seems to need its speed.) -- Pigeon Be kind to pigeons Get my GPG key here: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x21C61F7F
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