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[Heebs]

Just a question for the masses.  I replaced my stock fans with two Delta 50 CFM fans running off an external 12v wall adapter.  I also have the divider in my shroud and the GPU covered with some card to draw air through the heatsink.  But I do notice that my GPU fan doesn't pull as much air through as my CPU fan does.  Naturally I am thinking that this is normal because the CPU heatsink has far less resistance for the air to flow through and a larger space for the air.  Am I correct in this thinking or is something amiss?  

The air out the back is rather cool, almost room temp cool...  Made me worried at first but after I played bioshock for 4 hours with zero hiccups I figured I was fine.  

Thanks!

[qweewqaz]

My air feels weaker on the GPU side too but I think that is because the air current needs to move farther up to reach the vent then the CPU side. Cool air is never good, after a 4 hour siting it shouldn't be warm-room temp.

[myerz635]

My air was slightly weaker on the GPU side before i did the shroud mod but now they are equal. The air coming out of the gpu side is much warmer than the cpu side now. I'm using talismoon fans + a 60mm fan in front of the cpu heatsink along with the shroud mod....like qwee said, cool air coming out is bad after a 4 hour sitting. Something isnt right there, it would be impossible for the air to be room temp because that would mean no heat is being removed from the system.....gpu side should be hotter than cpu side. I would definitely be taking it apart again and re-checking everything!!!

[Heebs]

It must be cooling the heat sinks because it would of died otherwise.  I haven't messed with the heat sinks at all (IE not taking them off) so I know there is a good connection because my box is over a year old.
As long as you guys have the same deal with "less" air moving through the GPU side then I'm not worried.

Thanks.

[digitalman42]

I did the air shroud mod the divider and covered my GPU, also covered half my cpu just like the shroud has pictured.  I also did the bolt mod because my 360 had the 3rod, with the bolt mod I did the AS5 on the chips and heatsink.  I also installed Talismoon fans.  And after I gave for a few hours I hear the fans kick in high speed mode and I feel the back of my 360 and it blows out alot of air, and it's warm air, not hot, but warm.  And if feels like its blowing out about 40% more than before I did any mods.  I heavnt had any problems with games since doing the mods, my games use to lock up sometimes and now they dont.  
     I dont understand why your getting cool air, especially without having any EXTRA fans to suck cold air in and blow on the heat sinks.  Before I did the bolt mod the old generic paste on my chips had hardened and my heat sinks wearnt doing their job in keeping the GPU/CPU cool, maybe thats your problem.  I dunno.  On the other hand you might be fine, with the shroud mod and the better fans, it could just be keeping it cool, but I dunno, I have basicly done the same thing you have and mine blows out warm air.  IT's warmer than room temp but not a by all that much.

[RBJTech]

QUOTE(Heebs @ Oct 4 2007, 06:07 AM)

Just a question for the masses.  I replaced my stock fans with two Delta 50 CFM fans running off an external 12v wall adapter.  I also have the divider in my shroud and the GPU covered with some card to draw air through the heatsink.  But I do notice that my GPU fan doesn't pull as much air through as my CPU fan does.  Naturally I am thinking that this is normal because the CPU heatsink has far less resistance for the air to flow through and a larger space for the air.  Am I correct in this thinking or is something amiss?  

The air out the back is rather cool, almost room temp cool...  Made me worried at first but after I played bioshock for 4 hours with zero hiccups I figured I was fine.  

Thanks!

Spot on ..

I assume you are running the fans at the full 12v then ?  In which case I fully understand why you have cool air - running them at 6-7v is the sweet spot between noise and cooling, obviously at this voltage you will be getting hotter but slower air, at 5.4v stock it will be hotter still...

(IMG:style_emoticons/default/smile.gif)

[Heebs]

Yeah they are running at a full 12v constantly.  Thanks RBJ!

[SpRiTe ReMiX]

Actually cooler air coming out the back is better. On my stock fans, the air was burning hot coming out of there, even touching the back air hole vent plastic was really warm. Since I've dont AS5, better fans, divider, the air coming out is just slightly warm. Hot air = hot system.

This post has been edited by SpRiTe ReMiX: Oct 5 2007, 06:30 AM

[RBJTech]

QUOTE(SpRiTe ReMiX @ Oct 5 2007, 06:30 AM)

Actually cooler air coming out the back is better. On my stock fans, the air was burning hot coming out of there, even touching the back air hole vent plastic was really warm. Since I've dont AS5, better fans, divider, the air coming out is just slightly warm. Hot air = hot system.

The speed/flow/cfm of the air has a huge impact on the cooling capability.

The greater the flow of air with the SAME amount of heat transfer then the lower the AIR temperature will be.

So the idea is to get a BALANCE of airflow vs effecient heat transfer vs noise.  

The airflow divider and GPU cover mods increase the airflow over the GPU heatsink (making the GPU fan efficient rather than ineffective) so more heat is transferred to the air on the GPU side.

With just the above mods, hotter air is GOOD !  This means it's coming out the console rather than staying inside.  Therefore your comment about Hot air = Hot system is simply not true..

However, with a higher speed fan, then you can get even more heat out the system and the air coming out will be cooler (*) - so cooler air is good as well but as long as it's moving faster than stock...

(*) There comes a point (when running the fans @ say 12v) when the airflow exceeds the ability for the heatsink to give out (transfer) any more heat due to the surface area/design of the heatsink.

In the case of the CPU this is about 8v (ie above this and the CPU heatsink does not get any cooler), for the GPU then this is about 10v due to the very inefficient airflow path and low profile GPU heatsink design.

Education on airflow cooling over for today ... (IMG:style_emoticons/default/wink.gif)

Regards,

Richard.

[hlpoulsen]

I dont know, but if you take a look at the fans then you see that the blades are opposite of each other. In my opinion the fan at the GPU side suck air in and the fan at the CPU side push it out of the box.

[malmeid2]

QUOTE(hlpoulsen @ Oct 5 2007, 03:07 PM)

I dont know, but if you take a look at the fans then you see that the blades are opposite of each other. In my opinion the fan at the GPU side suck air in and the fan at the CPU side push it out of the box.

The blades on both fans, stock or talismoon, are facing the same way and also spin the same way. Get your eyes checked, I just had to update my Rx with my optometrist last week also  (IMG:style_emoticons/default/laugh.gif)