Quick question...a nOOb question, but valid, nonetheless.

The airflow from a fan on top of the heatsink is to flow which direction? Is it to pull the air up from the heatsink and blow it away? Or, is it supposed to pull air from the case down towards your heatsink?

I only ask because originally, I had it set up like AMD recommended, which is to pull the air up and away from the heatsink. I was running 48C idle and 50C full load. This morning, I switch the fan around so it would blow down on the heatsink and guess what? It runs 47C idle and 53C with a full load. Room temp is set at 72F (22C). I do have some UV CCs that heat up and it is a mini-ATX case.

I'm getting the temps from SpeedFan. Can't use MBM because it's an OEM board that it won't recognize (the board is an Asus, too).

Any advice would definately help this nOOb because he's totally freakin' clueless.

Rob

AMD Athlon XP 2400+ (not overclocked)
SLK-900A heatsink
80mm Panaflo with no speed control...running full blast.
No cable interference

One 80mm intake (pulling from straight down with no interference)
One PCI Slot fan exhaust/One 80mm exhaust (top of case blowing straight up)

M00ns ago when I was recommemded gear on this site for my first time OC I asked the same question.
I had the SLK-900 and a 92MM Panaflo, was told it should push air into the HS I thought it was the other way around but no.
It did lower my temps quite a bit.

EDIT: I don't think starting a sentence w/ a preposition is correct, or is it ending it not correct ??? )

That title, uhm, sounds like you are referring to something else. lol.

4 fronts out, top fan out, 2 back fans in, side fan in. thats mine.

hawklen, i think he was specifically talking about the HSF.

seeing as how mine came attached (zalman 7000a) and the plug is not reversible, I don't really have a choice, but it's blowing out. whichever way works better is the way it should go


noslak, it's ending that's a no-no.

"And you would find the library where?"
"Probably in a place where we end sentences with prepositions."
"Ok, fine. And you would find the library where, you idiot?"

This was debated at length on silentpcreview.com. The best (in my arrogant opinion backed up by scientific evidence which I am too lazy to link to) method is to have the heat sink fan blowing down into the heat sink.

Basically, this makes sure that more of the heatsink comes into contact with the air. Also, blowing outward deprives the center part of the yummy air that it finds so delicious (I think I said that in not so many words in the last sentence, but I am redundant and repetative sometimes quite often)

Oh, and it's wrong to end a sentence with a preposition.

[edit: however, there may be heatsinks that this is not true for, given the wide variety of designs.]

Blow it, don't suck it.

You've already got your answer from the looks of it. Whichever way gives you lower temps is the best. I find experimentation to be the best sourcec of answers, but if you want opinions....mine works better blowing onto the HS.

I agree with lAnonymousl , it depends on the heat sink design. I tried with a few and it seems that blowing in works best on strait vertical or horizontal fin sinks and pulling out works better on orb type sinks.

I have the slk-900a and i blow onto the HS with my tornado. Surprisingly i really dont notice it anymore. I said i dont notice it any more!

Sorry for being off topic but I can't believe we haven't had any Spaceballs references yet.
It's Mega-Maid! She's gone from suck to blow!

Quote: Originally Posted by Sparky I have the slk-900a and i blow onto the HS with my tornado. Surprisingly i really dont notice it anymore. I said i dont notice it any more!

Me too, but when I switched it around it was a LOT less loud

Thanks for the input, Pimps. This morning, I switched it back around again and it's running 2C cooler with it pulling the air off the heatsink.

I guess this is going to be one of those enternal debates that could vary depending upon a variety of factors, such as the size of the case and how the air flow is set up. With this mini-ATX case, it's pretty crowded and I've managed to improve the air flow dramatically from what it used to be and after changing the heatsink and fan out, it's running around 48C now. I know I could get it cooler with some work, but I've put too much time and attention into this crappy OEM POS. If I had built it myself, it would be a different story.

I guess there are two important things that I can take away from this. First is that continued experimentation with the airflow will help me better understand how to get peak performance out of my system. Secondly, that the presence of a heatsink fan is vitally important to the continued operation of an AMD chip, right Kayin?

(just playin', CR)...

Thanks again and hopefully one day real, real soon I can afford the time, energy, and money to build a proper system.

Rob

well if its sucking, its just pulling hotter air off of the mobo...


also, case manufacturers seem to think blowing is better, seeing as all the fans on side panels over the socket blow in...

Quote: Originally Posted by -=XPS=- well if its sucking, its just pulling hotter air off of the mobo... also, case manufacturers seem to think blowing is better, seeing as all the fans on side panels over the socket blow in...

Well, apparently AMD doesn't give a damn either way. At least, that's what their techs told me four weeks ago when I called about this issue. Whatever I get cooler temps with, they said.

Turn it around...you're just blowing hot air not only onto your mobo, but your blowing the heat right back towards the bottom of the heatsink where, guess what? Your cpu is right underneath there. Think about it. The heatsink is meant to pull air OFF the cpu. Your fan is blowing it right back at it. The heatsink runs a whole lot hotter than the mobo, anyway.

See how the arguement swings both ways?

Like I said earlier...whatever gets you the coolest temps is the direction you need to have your fan set up. A wide variety of things play into the equation such as the heatsink material, the design, size, fan size, mobo layout, northbridge location, northbridge heatsink style, case airflow, case design, case material, ambient room temperature just to name a few.

Rob

If you have a square heatsink dont forget the 'sideways' option. Going sideways can lessen the "deadspot" effect from the fan hub.


Dakas: Sup CPNS7000 buddy? Having one of these kills the option of playing aroud too much... oh well I guess its just a sacrafice we make for having the best heatsink on the market.

Quote: Originally Posted by M.D.K. If you have a square heatsink dont forget the 'sideways' option. Going sideways can lessen the "deadspot" effect from the fan hub.

...which is why I've been dying to try out the new Aerocool Hightower HT101.

Anyone got one they can take a pic of and post some stats?

Rob

Exactly. The HT101 looks like a revolutionary heatsink.... even if it makes zif sockets everywhere tremble in fear. I'd get one myself, but I'm very happy with my 7000cu, and I'm sure the 7000 would be a hell of alot quieter.

Quote: Originally Posted by M.D.K. If you have a square heatsink dont forget the 'sideways' option. Going sideways can lessen the "deadspot" effect from the fan hub.

Tunneling is another great method for deadspot elimination. If you have room to sideways tunnel, give it a shot! A blower is probably the best air-cooling device to stick on your HSF.

Speaking of blowers, if any of you metal fab pimps want to try something original (case with lots of room would be a requirement) for a HSF fan, PM me about one of my 115volt 92mm centrifugal blowers..... I can make you a really sweet deal.

Blowers are ridiculously loud and don't push as much air as a normal fan. Yes they remove the deadspots, but their performance as a heatsink-fan is sub-par.