why not make heatsinks extend outside the case?

draggoon01

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May 9, 2001
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of course, the cpu or gpu would have to be closer to the periphery of the case. but make the heatsink go from cpu through a hole in case, to outside. then there could be some grille or cage to protect against touching it. the goal would be to not need a fan on top the heatsink.

ever run your case with side panel open and case on its side? runs lot cooler
 

Lord Evermore

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Oct 10, 1999
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Because it would need external supports, and would be HUGE and heavy, and expensive. And cases would have to be designed for it, which would require some sort of standardization. For video cards it would be difficult due to the limit of PCI/AGP slot spacing. Plus it would just look ugly as hell.

Oh, also, you'd have issues with making sure the surfaces mate properly. Since the heatsink has to be secured to the case somehow (else it would fall off), you'd have issues with making sure it lined up and attached to the CPU socket properly. I'm sure everyone has experienced the difficulty of getting a motherboard to align in a case so that the I/O ports lined up, and then having the PCI slots not quite perfectly aligned so some cards have to be forced in or the board has to be readjusted slightly. Considering that the only way to be sure an externally-extending heatsink is on properly would be to turn it on and risk burning out your CPU, I can't imagine there'd be much of a demand for it.
 

grrl

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Jun 21, 2001
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Originally posted by: Lord Evermore
Because it would need external supports, and would be HUGE and heavy, and expensive. And cases would have to be designed for it, which would require some sort of standardization. For video cards it would be difficult due to the limit of PCI/AGP slot spacing. Plus it would just look ugly as hell.

For all the above reasons PLUS, you'd still need a fan for best efficiency (even acceptable efficiency I'd think).

Edit <<ever run your case with side panel open and case on its side? runs lot cooler>>

That's only true if your case lacks adequate airflow, not simply because the heatsink is 'in direct contact' with the ambient air.
 

Lord Evermore

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Oct 10, 1999
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A very slow large fan would work well enough, similar to current water cooling setups. For that matter, I guess it could be made pretty just like watercooling can be, but it'd be expensive and really not very worth it.
 

grrl

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Jun 21, 2001
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This reminds me of an old thread where someone was asking about making the whole case into a passive heatsink. The thermal conductivity of metal isn't great enough to make a truly passive system possible when a CPU is pumping out 60+ watts or whatever.
 

Lord Evermore

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Oct 10, 1999
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Ooh, how about a double-hull case with water in between and the outer hull a giant heatsink? Wouldn't even need to be a direct attachment to the case, just a tubing setup like current water coolers, with a quiet pump inline.
 

Rotax

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Oct 10, 1999
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How bout a big heatsink on the back side of the case (well more of just a chunk of metal of some type [copper?]) and use heat pipe tech? Still have a decent copper sized heatsink on the CPU and a bigger quiet fan, but then heat piped to the case h/s? Hmmmm Could even have the top of the case "heatsinked". :p Somone needs to try this. haha I'd think it could have potential..maybe.. But I could bet it wouldn't be any cheaper than a decent water cooled setup. lol So... It'd still be kinda intersting. Case as a big HS would prob really warm a room up tho, eh? hehe Be like a lil heater.. haha
 

HokieESM

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Jun 10, 2002
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I realize its only a Via... but take a look at the Hush PC. Completely passive cooling--for the PSU and the CPU. The sides of the case are the heatsink--the heat is carried by heatpipes to the side.

Oh, and on a side note, a guy built a P4 3.06GHz with an enormous heatsink (roughly the size of a computer case) and used one of the passive PSUs to build a very quiet computer. I remember reading about it at SilentPCReview.

Oh, and as far as putting heatsinks outside of the case, check out this 350W fanless power supply.
 

Lord Evermore

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Oct 10, 1999
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A good while back, someone, I think maybe Thermaltake and someone else, made an external heatsink design for Socket370 I believe. It was a metal block on the socket with a heat pipe going to a very small radiator encased in a plastic tunnel a few inches long with a small fan blowing air through it. It didn't work very well. But it was very small.

That silent PSU looks like a very bad idea. Sure, it's got a heatsink on the back, but the contact area between the external heatsink and the internal is very small, and isn't exactly going to be the best interface. The fins inside the PSU are also going to be radiating heat, and there's nowhere for that heat to go except up and into the case. Passive vents above the PSU going to the rear on a tall case wouldn't really help much, and installing a fan defeats the purpose of the silent PSU; a hole above the PSU as the review showed would help somewhat though.

The extra fins arranged all over the inside, on areas where the heatsink isn't touching anything, seems like tacit acknowledgement that not enough of the heat can be transferred to the external sink.

Besides that, for a 350W PSU, those are some absolutely terrible numbers. I'm not sure how they get away with calling it a 350W PSU. There seems to be a version 1.2 with much better output levels though. But 235 bucks for a power supply?! An Antec 330W PSU puts out about the same power levels and is as near to silent as it's possible to get using fans and costs 20% of that.

Good review methods though. Would have been nicer if they'd canned the thing due to not actually being what it claims to be.
 

HokieESM

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Jun 10, 2002
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Lord Evermore --> Yeah, the 350W PSU isn't exactly the best--I just posted the link to show draggoon that some people had indeed thought of his idea. I think what's really limiting the fanless PSU is the ATX standard--which leaves very little exposed area. Oh, and just so you know--if you think your Antec True330 is quiet, you should really try some of the "recommended" power supplies at SilentPCReview. I recently bought one of the 300W (which is at 70% capacity... Tom's tested it at 380W max capacity) Fortron PSUs with the 120mm fan--its REALLY quiet (much quieter than my Antec True430).

Oh, and personally... if people really want a quiet computer, they should urge Intel and AMD to follow suit. Banias shows that a good processor doesn't need to make 70W of heat. (Actually, I'd LOVE to see a Pentium-M based small-form-factor with a QUIET power supply--the Shuttle is just too loud). And if you only needed 25W to power your processor.... you might could "make due" with a 250W power supply (which, in turn, could be quieter, etc etc).
 

Lord Evermore

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Oct 10, 1999
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We'll never be allowed to have Banias in our systems. :)

Though maybe Intel will see the light and make the next Pentium do more work per cycle so the clock speeds aren't so high and the CPUs aren't so hot but they perform just as well, like Banias. Which I think is just a P3 redesigned. :) I wonder what AMD would do with their PR system if Intel started using lower clock speeds again. Will Intel EVER be able to revert to a high IPC design again without looking like they're making slower CPUs and letting AMD market it that way?