Are You Blowing Or Sucking?

[VIAN]

I did tests on my CPU fan. I've always had it sucking, but wanted to see if there was a benefit to blowing. To me, blowing makes no sense, but ever manufacturer ships it that way, so I was curious. This is in a closed case, specs in sig.

Before each test, the computer was off for 8 minutes.

When Windows loaded it was at 46/27. Ran burn in test from Sisandra - both CPU tests 10 times at high priority.

Sucking: 55/28

Blowing: 63/29

So, clearly Blowing is a bad mistake. Any of you have similar results.

 

[viivo]

It depends on the HS design. Fan location also comes into consideration - an intake directed at or near the cpu socket with the HS fan blowing back at it probably wouldn't yield good results. Different strokes for different folks and their billions of case, airflow and heatsink combinations.

I'd be interested in seeing the idea combined with a duct mod, though.

 

[beatle]

I don't have a choice.

<-- Zalman CNPS-7000a user.

I also have a 120mm intake in the side of my case that sits over the CPU, so even if I could turn the fan around, it'd be fighting the intake.

 

[VIAN]

that sucks.

 

[saxophonoia]

I have the slk-900 and a tornado that blows.......works fine for me

 

[jagec]

Originally posted by: VIAN
I did tests on my CPU fan. I've always had it sucking, but wanted to see if there was a benefit to blowing. To me, blowing makes no sense, but ever manufacturer ships it that way, so I was curious. This is in a closed case, specs in sig.

Before each test, the computer was off for 8 minutes.

When Windows loaded it was at 46/27. Ran burn in test from Sisandra - both CPU tests 10 times at high priority.

Sucking: 55/28

Blowing: 63/29

So, clearly Blowing is a bad mistake. Any of you have similar results.

the only thing your tests "prove" is that in your system sucking works better than blowing. In many systems blowing works better. It varies from heatsink to heatsink, the only way to know for sure is to test it yourself.

Why does blowing make no sense to you?

 

[JiggaJohn]

Quick question... does the Zalman CNPS-7000a do an good job of cooling the cpu?

I have a p4 1.8 ghz right now and my comp freezes all the time when i play wc3 due to excessive heat. The stock hsf does a pretty crappy job.

any suggestions?

 

[jagec]

Originally posted by: JiggaJohn
Quick question... does the Zalman CNPS-7000a do an good job of cooling the cpu?

I have a p4 1.8 ghz right now and my comp freezes all the time when i play wc3 due to excessive heat. The stock hsf does a pretty crappy job.

any suggestions?

if you're not overclocking, the stock heatsink should do OK if it's properly mounted. Did you apply a thin layer of Arctic Silver when you mounted it? And do you have a couple case fans?

 

[VIAN]

Why does blowing make no sense to you?

Because, with sucking, it would be sucked through the heatsink by the CPU fan and then sucked by the chassis fan to the outside.

With, blowing, It would conflict with the chassis fan because they are both sucking the same air and most likely, the air that has already been blown down, will be sucked again into the CPU fan before it ever reaches the chassis fan.

Maybe it is design. This is my first case. Had it for 2 years.

 

[RS3RS]

I blow.

I tried sucking once, and... It sucked. Temps were about 2 degrees higher (92m panaflo, Thermalright SP-94)

 

[EarthwormJim]

I always gag less whenever I blow...

 

[Nebor]

Originally posted by: EarthwormJim
I always gag less whenever I blow...

Me thinks you don't know what you're talking about. You should definitely not try to to inflate your partner.

 

[daba]

My fan blows... I idle at around 25C with Thermaltake 92mm SmartFan and SP94.

 

[stardust]

Did a test on my watercooling system.

CPU: A64 3000+ @ 2.4ghz 1.6V

Sucking: 35C idle
37C load
32C case temp

Blowing: 30C idle
34C load
28C case temp

 

[rancherlee]

SLK-800A with TT smartfan II

Suck = 49*C full load 30*case
Blow = 53*C full load 30*case

 

[dabuddha]

hmmm I wonder what would be best for me? I have the Antec p160WF with the 2 stock 120mm fans (one in front and one in back) I'm using the slk-900A with an 80mm panaflo blowing down currently. Perhaps I'll try sucking

 

[Tab]

Wow, one of VIANs threads has a comedic value to it

 

[jhurst]

Originally posted by: JiggaJohn
Quick question... does the Zalman CNPS-7000a do an good job of cooling the cpu?

I have a p4 1.8 ghz right now and my comp freezes all the time when i play wc3 due to excessive heat. The stock hsf does a pretty crappy job.

any suggestions?

I can't imagine a P4 1.8 locking due to excessive heat......those P4A's do not put out nearly as much heat as the P4C/E and they run fine with stock cooling (unless overclocking). I'm thinking you might have a vid. card driver issue......or your power supply is crapping out. I would rule out your processor overheating......Intel made the HSF fool-proof with the retention system for P4's.......thermal paste is not required either with the "thermal pad" put on the stock coolers.....

 

[jhurst]

I use a Zalman CNPS7000-Cu and it cools great.

Stock cooling (2.8 @ 3.4) : 44 idle, 65-68 load (P95)
Zalman cooling (2.8 @3.5): 38 idle, 50-53 load (P95)

Using an IC7....so temps might seem a little high

 

[Jaxidian]

My fan on my SLK800 has a duct over it so it is pulling in air from outside the case. With this duct, I'm definitely blowing. Even under load, I don't get much higher than about 37C on my 2500+ Barton at 3200+ speeds. If you have a duct such as this, sucking doesn't make much sense.

 

[VIAN]

Yes, I agree if you can get fresh air to the fan, then blowing is the best method.

Where does the hot air exit the case?

 

[Jaxidian]

Originally posted by: VIAN
Yes, I agree if you can get fresh air to the fan, then blowing is the best method.

Where does the hot air exit the case?

I've got one of those Arctic coolers for my Radeon 9800 Pro that is one of my outgoing fans. My PSU is an out-going fan. I also have a little 40-60mm (don't remember which) outblowing fan right next to my duct/cpu. I have incoming a side panel fan and the front fan. I've experimented with additional out-going fans but they don't seem to make any difference, so I've stayed with this setup.

 

[Big Lar]

When I do use Air, I ahem, suck the airoff, I always thought it best to keep the Hot air off the board and mosfets, versus heating them up. Just IMHO

 

[HardWarrior]

If you're sitting in front of a fan do you think it would cool you better by blowing air over you or sucking air past you? I'll take the blow any time.

 

[VIAN]

But if the air is hot than sucking would be better. We are relatively cool compared to these extreme temperatures. Plus, you aren't made of metal. I tried using a fan on my hand and sucking made my hand much cooler. Delta 80mm 5400RPM. Too loud to keep it in the case though.