That's debatable. From my experiences, it seems much easier to blow heat away than pull it away. I think a faster fan is required to get the full effect of fan reversal.. For example..

I put a 7200RPM delta on my copper SK6 heatsink backwards... My CPU (Athlon XP 1.33Ghz) locked up in a matter of minutes.

I turned it the proper way, my system idled at a 33*C, which to this day is a temperature I rarely see with my 4500RPM fan.

I went from a non-reversed Delta 7000rpm fan on my Thermalright SK6 to a reversed Y-Tech 4500rpm fan and only increased temperature by about 3-4 degrees celsius.
I found that blowing down on the SK6 has been quite efficient for my cooling on my Athlon 1.4Ghz @ 1.5Ghz. Saying that I haven't fought with the SK6 clips to try it the other way round to see what sort of temperatures I get....

I was refering to his exhaust fan, not the CPU fan.

That's what I get for skimming instead of reading.


SuperCheetah: I use a Thermalright SK6 heatsink on my Athlon XP 1.3Ghz. I couldn't be more happy with how it performs. Coupled with a decent fan, it's extremely capable, not bad looking and not extremely heavy.

I think the efficiency of pulling air away may be affected by the design of the heatsink and fan. It does sound logical to pull hot away away, rather than try to blow it off... But it might require some specialization.

That is true Rick, but there are those who will argue the other way. Though I'm not one of them. I think you know of my adventures in cooling. If your fan has the power to pull the air away then it is much better than just trying to blow it off of the heatsink.

So let me get this straight. If you have a fan blowing air away from the chip, then your temps will be higher or lower??? I assume higher, as it takes more fan power to suck the air away from the chip. This does make logical sense as the right way to have it, but I can't say I've tried it this way yet. But if you have to have such power to suck the air away then it kinda defeats the whole purpose of lower temperatures in the first place. Maybe I could design up some mod to do both at the same time. Don't really know how that would work, but I'm sure I could figure it out.

Any more comments on blowing air on or sucking it off the chip? I'd really like to know which way works better and allows for better overclocking abilities. Thanks for the many comments on my question, you don't know how helpful you guys have been. Much props to 3DS and the great members it has!!!

Yoink --> XP 1900+ CPU Fan, old 3DS forum

I think this greatly depends upon the design of your heatsink and fan.

As I mentioned above, when I turned over (reversed) a 7200rpm Delta fan on my SK6 heatsink, it overheated within minutes. This is also without any appreciable CPU activity... Just sitting in the BIOS not doing a thing.

When I turned it the right way (non-reversed), I had a temperature of around 33*C.

However, if I am not mistaken, there are heatsinks that require a reversed fan to work properly. So reversed vs. regular fans is a topic that is very debatable.

I think the Delta is probably too powerful to be reversed. Not sure though, I was just real happy to get rid of it after putting up with it for a few months...
As previously stated I haven't had any problems with my SK6 and reversed 4500rpm Y-tech fan. I guess the blowing onto the heatsink must cool the copper base in conjunction with blowing any heat in the air away from it. The SK6 design has loads of fins mounted which I think helps with the channelling of air being blown away from the heatsink.

Long thread & deservedly so. Lotsa good info.

If I may: I don't think that box fan you having blowing across the mobo is magnetically shielded SuperC. I don't know the 'field' it disperses, but you might want to remove it & get some shielded/non-magnetic fans to replace it.

Pitch/contour of the fan blades will determine if the fan draws or blows, AFAIK. Ability to disperse the flow adequately (if it blows & is heatsink mounted) is dependant on the design of the HS. Cooling the 'sink doesn't necessarily cool the chip either. The heat from the chip has to be transfered to the 'sink 1st otherwise ... Compounds like 'Artic' are great for this, IMO.

Just my thoughts & if I re-iterated anyone else (it was a long thread) just count it as 2nd'ing their opinion.

You can avoid damaging your motherboard,memory,etc....when removing your hsf combo by NOT using a regular screwdriver,try this easy method instead;use a multi-bit screwdriver without the bit,just the open hex end that normally holds the bit,or you could use a 1/4" drive ratchet extension with a 3/16",or 1/4",or 5/16" socket on the end of the extension.(whatever fits your clip the best)You will be able to provide the neccesary downward,as well as sideways pressure to release the clip.I've seen too many postings where people have damaged their motherboards while doing this procedure with just a screwdriver,(It slips off)
also, get your self some silver compound(artic,antech)and follow the directions to the letter.

this is a bit off topic but be VERY CAREFUL with the AS II. it is a great thermal compound but if it gets on any part of the CPU other than the die you may be in serious trouble. i almost fried my chip by getting some on the contacts and was VERY lucky i could save it. well enough of my warnings

As i think i've mentioned before, i cannot recommend the Zalman HS & Fan combo highly enough. For those who want silence, you can have it, for those clockers/modders (u know who u are) the fan has a variable speed control, with which you could freeze hell with.

My Zalman fan

I have a ThermalRight AX-7 with a 120mm Panaflo 69CFM fan and 80 to 120mm adapter. I added a 25Ohm, 3W Potentiometer to control the fan speed. It's virtually silent pushing 40-50CFM.

It seems like the Thermalright SLK-800 is the king of all heatsinks now. It's all copper, and is in a V shape. One of the things I like about it is it has a 3 cleat clip, meaning in clips onto the 3 cleats available on the socket. It also has steppings to allow you to use 60, 70 or even 80mm fans on it...which is very nice.

A new entry to the cooling technology field. I believe it uses 'peltier' effect and a heatsink/fan plus fan speed controls for all your PC fans. Designed for quiet operation. Haven't seen any test reports yet though, and don't know where you can buy one. Interesting none the less.

Active Cool produces AC4G, the world's first and only smart thermo-electric cooling system for PC CPUs.

AC4G's patent-pending solid-state cooling represents a significant leap forward in cooling power, processor temperature control and monitoring, and computer noise control. Installed in any PC in less than 90 seconds.

http://www.activecool.com/products/HowItWorks.html

Just kept reloading through Opera 7.01.
Loaded fine in IE6.

Also check out this water assisted CPU cooler here

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Arris
Also check out this water assisted CPU cooler
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Interesting cooler ...

At 36dBA noise level its not exactly quiet, its also rather large, and I don't like the idea of having water anywhere near electronics components even if a leak is unlikely.

Also it does'nt work, check out this test report ...

Water Assisted Cooler - Test Report

These days I think most users are more interested in quiet operation over cooling performance, but it's nice to have both.

The new Vantec AeroFlow rocks.
XP2600+ .....surfing 33*C and after a 2 hour Quake3 workout 40*C
and it only costs $30.00 US

I've now got a 2100+ Tbred B @ 13x167 2.171Ghz (~2700+) with a SLK-800 and a YS-Tech Silent 1950rpm 20dBA fan.

• Idle is about 35C.
• Load hits about 40C.

Now for a quiet setup (2 case fans and CPU fan all < 2000rpm) this is a killed heatsink!