Suck Or Blow?

[Wardie]

Well, the subject title may sound... abit politically incorrect but I could not sum it up in a better way.

I noticed a thread elsewhere on the internet about if people actually setup their fans to suck air from the heatsink, or blow air directly onto it. The strange thing was, alot of people did actually have the fan removing heat and pushing it towards their extractor fans. Most fans and heatsinks are designed to have air blown onto them, yet so many people had their system sucking the air out?

What do you find best?

[Hardass]

I have tried both, and found air blowing onto the hs worked best for me.:)

[IFMU]

From everything I have tested, blowing onto the heatsink has always worked best.
I can see how it could vary slightly dependant on the rig, but realisticlly, blowing is the norm and typically better.

[migginz]

Blowing from a distance is best as it eliminates the deadspot and some of the back pressure.

I got a 9c drop by putting a 120mm fan in the side of the case over my swifty.

[antipop]

Try both!! It takes you less than 2minutes to change the direction of your fan
I think blow would be better

[Tedinde]

I use to use Alpha's on everything. If the northbridge wasnt activly cooled i use to have the fan blow. For the cooling, If it was fan cooled then suck.

Im assuming your using an alpha with a shroud, If not, then you shold blow.,

[CCW]

Originally posted by antipop
Try both!! It takes you less than 2minutes to change the direction of your fan
I think blow would be better

As antipop says, try it yourself to see whats best for your system but I have always had it blowing as it requires less pressue to push air down over the fins.

Craig

[asw7576]

you never know until you tried it...... some heatsink become cooler with sucking air method, and other need blowing air.

It just 10 minutes test.

[PyroTeknik]

flipped fan on my slk-947 and it increased temps by 3-4c

[Fisk]

thats nice..

[smithy]

i think I am the minority...I blow away from the diode- reduced temps by 2c--go figure- I guess it all comes down to the configuration of your case- but I blow away and my temps are solid. When I blow in- the temps increase-my 2c's

[TheDogFather]

I saw this come up the other day, might even of been the same thread.

I allways thought blowing was best, but some were saying, thier heatsinks came with the fan sucking, and others were saying changing it to sucking improved temps.

So I'm with give it a try, it depends on your setup.

TDF.

[S!1v3rB@cK_Dk]

My SLK900u is best if the fan is sucking

[smooth_criminal]

When I set it to blow my 2.8E jumped 10c :mad: Had to revert to suck and all was well.

[saaya]

yeah the alphas are performing a lot better with a fan sucking the air away from them for some reason... and some people say it also works better that way with their swiftech heatsinks.

most heatsinks work better with a fan blowing air on them though... unless you have a casefan in the side panel of your case right above the cpu heatsink that sucks out the air of the case you should get better temps with the fan blowing on your heatsink...

[smooth_criminal]

Originally posted by saaya
yeah the alphas are performing a lot better with a fan sucking the air away from them for some reason... and some people say it also works better that way with their swiftech heatsinks.

most heatsinks work better with a fan blowing air on them though... unless you have a casefan in the side panel of your case right above the cpu heatsink that sucks out the air of the case you should get better temps with the fan blowing on your heatsink...


Well I have 2 fans on my side panel and I also have 2 more fans in/exhaust. As cool as my case can be you can feel heat being generated from the CPU. This was not the case with the C ships. Freaking Prescott's, I'm considering a new cooling solution. How much better does the Zalman 7k perform over the alpha?

[deltawing11]

I have (still) an open system (no side walls) and 2 fans on the heatsink, SK-7. Directly on the heatsink is 80mm Evercool/Titan 28cfm (and it is loud) and from the side of the HS (4cm) is one Enermax 120mm blowing. At the beginning I had both to blow on the HS and was satisfied with the temps I got. Without Enermax (always on half speed) I have 3°C higher temps. However one thing I didn't like was that the hot air from SK 7 was going directly to the capasitors and mosfets (NF7-S V.2.0) and thus negating the efect of Enermax blowing also over them and memories. Changing the 80mm fan on the HS to sucking I got almost no change in temperatures (measured with a thermal probe from the side of the CPU) but my mosfets are sooo cool now :-))) I'll leave it like this till my watercooling next week :-)

[chr]

blowing onto gives me better results, by 3-4c

[nowareman]

Originally posted by saaya
yeah the alphas are performing a lot better with a fan sucking the air away from them for some reason... and some people say it also works better that way with their swiftech heatsinks.

most heatsinks work better with a fan blowing air on them though... unless you have a casefan in the side panel of your case right above the cpu heatsink that sucks out the air of the case you should get better temps with the fan blowing on your heatsink...


I have a Swiftech MCX4000 with a modded Alpha intake cover on it and I'm using a 120mm Sunon Low Speed for my HSF sucking air off the HS. With this setup my CPU temps are 2F lower sucking than blowing.

I agree, saaya, blowing is better in general. I think the reason the Alphas work better sucking than blowing is the intake cover which keeps the airflow at the base of the HS. My Swiftech got better temps blowing before I put the intake cover on it.

And the 84CFM HSF makes a difference.
:D