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[iateshaggy]

tldr, but i have seen dual cpu heatsink mods fail, so i doubt a pc heatsink will produce any different effects.

[strapmonkey]

The only mod that has ever failed me was when I knackered the mobo on a falcon when the screwdriver I was using to remove the x-clamp slipped.  So, it really wasn't the mod that failed, it was the modder.  Not uncommon.  We are imperfect vessels.

To be completely honest, I'm somewhat amazed at how physically robust my 360's have been (for all their delicate sensibilities when it comes to heat).  I've torn down my current Jasper mobo more times than I'd care to admit, put God knows how many hours on it, and it keeps on keepin' on.

In terms of the original case, original form factor, a 1U copper or copper core heat sink, properly installed and ducted, will certainly outperform the aluminum extrusion that MS used for early revisions.  The 2nd gen GPU heat sink is a little better than the original, but a 6mm heat pipe attached to a very small fin stack is good for perhaps 20 watts thermal dissipation.  Small form factor server heat sinks are generally designed to cool ip's with TDP's of around 100 watts.  These sinks are capable of dissipating more than 100 watts with a little foresight and appropriate accommodation (e.g. proper ducting).  I wouldn't trust a plain aluminum extrusion like the 1st gen GPU sink with more than about 45 or 50 watts dissipation, and that's stretching it, yet MS used it to cool a GPU pulling 75 or 80 watts, easily.

In terms of using 360 CPU heatsinks on the GPU, they are capable of handling the thermal output of the 360's GPU, but aren't well optimized for ducted passive performance.  The 2nd gen CPU sink is a little better off in that regard because it has a looser fin pitch than the 1st gen sink.  Using a 1U or 2U server heat sink, a solution optimized for the ducted passive role in tight quarters, you will get better performance than either generation 360 CPU or GPU heat sinks are capable of achieving.  In other words, the reason you've seen dual CPU heat sink mods fail is partly because the CPU heat sinks aren't well configured for that role.

In all honesty, the 2nd gen GPU sinks will keep a 360 running, and maybe for the practical life of the console in many cases.  The majority of PC CPU heat sinks are substantial over kill for the TDP of either 360 chip.  If you have plenty of time on your hands, and are interested, there are better ways to cool an Xbox, but it's not necessarily mission critical, and that's not what I am suggesting.  I am merely responding to queries I have seen in this forum and others wherein individuals have inquired about the possibility of using PC CPU heat sinks to replace the OEM Xbox equipment.  And, as discussed in the original posting, yup, it's possible, but it takes some work and you really have to want it to happen.

I think even if you do manage to address the CPU and (esp.) GPU thermal shortcomings of the 360, there are still some real challenges in the thermal design of this console.  The video composite chip (aka HANA) gets hot as hell down there.  The RAM chips also run a little warm, though nothing as outre as the HANA.  The south bridge (roughly) chip gets balmy as well.

Really, if Bill G. would've payed me a small onetime consulting fee back in 2004, say $500,000 or so, I think I (and pretty much any well informed user of this forum, or any 12 year old junior high student well versed in computer hard ware, really) could've solved what was to become a 1.5 billion dollar liability with the following suggestion; "Gee, Bill, it'd probably go better for you if you put the DVD drive UNDER the motherboard.  I mean, you'll have the same form factor, your DVD tray shifts down an inch or two, and you'll be able to vent heat from your CPU and GPU much more efficiently using low profile heat sinks".  On that note, equalizing the air flow across the full width of the 360's heat sinks would've helped a great deal as well (i.e use the same heat sink profile for both chips from the factory, rather than devoting the lion's share of the air flow to the CPU [which doesn't need it as badly as the GPU] merely as a result of really sloppy thermal design).

But, although I waited by the phone for many an hour, the call never came, and we got what we have now; that is varying degrees of hardware failure in any given generation due to poor thermal planning on someone's part.

I didn't mention this in the original posting, but I don't think the Lian Li case was very well thought out, either.  It has superior thermals, but it damn well better, considering the size of the thing.  I had to figure out a way to invert the DVD drive to be able to use my 360 in a horizontal configuration, because as it came from the factory, the LL case had the retention tab in the DVD tray on the upper part of the tray, meaning that when gravity reared it ugly head (at 10,000 rpm no less) the disk would sort of flop out of the tray.  Also, LL's enclosure is prone to vibration, a problem I have spent a good many hours addressing in some fairly creative ways, not all of them soothing to the nerves.

[iateshaggy]

once again, tldr.

[strapmonkey]

Wellllll, if you didn't read it, you can't really comment on it, can you?  I mean, you can, but it's not really germane.

That one wasn't tl, was it?

[strapmonkey]

I misspoke in my second post.  The Alpha model number I gave as a possible replacement for the stock 360 slim heatsink is actually optimized for lateral, not vertical, air flow.  One of the pin fin models for socket 478 or 775 that conforms to roughly 85 mm x 85 mm would work well.  One of the PRE9060 models should work well for this application.  These models are available from the Alpha website, but they are outside my budget at $43 or so (to reiterate, I'm not affiliated with Alpha in any way, shape or form, they just make the best non-heat pipe thermal solutions for electronics cooling in my opinion).  You may find one on Ebay for less.

To clarify the purpose of this post; if your 360 is under warranty, and works, DO NOT mod it.  Let MS worry about any repairs it may require.  If your 360 is off warranty, or (like me), you have more balls than brains, it is POSSIBLE to mod PC heatsinks to fit either processor in a 360.  Exactly which heatsinks depends on whether you desire to maintain the original enclosure layout, or the original enclosure at all.

If an appropriate PC CPU heat sink is modded and installed properly, you will achieve thermal dissipation on par (worst case scenario) or significantly better than that obtainable with the original heatsinks, either 360, or 360 slim.  If you fail to observe basic thermodynamic and aerodynamic considerations, you'll get worse results than the stock solution managed, and then what's the point?  

Except that a fat 1 pound + (540 gm modded weight for my SLK 900) of shiny happy copper on your board just looks cool, I suppose (it does) even if it doesn't really outperform the 2nd gen CPU heatsink you had on there before (it doesn't, at least not in passive mode, because the SLK 900 was never intended for horizontal flow passive cooling, but the pendulum swings when you slap an 80mm fan blowing into the fin stack as originally intended by Thermalright).

For those of you who are modding or repairing these consoles on a regular and professional or semi-professional basis, none of what I've stated is really practical for the majority of your work.  It's not really practical at all.  It is fun, though.  And that's why I bought a console in the first place.  To have fun.

[hangover]

Interesting post strapmonkey, if MS had lowered the power consumption of the launch 360 down to Jasper levels and fitted the 2nd gen heatsinks from the start it would be a totally different story.
 Then the thermodynamics of the case and components would be less of a problem.

[iateshaggy]

i'd imagine if they could have put more efficient chips in from the get go, they would have.  it is actually way cheaper to make those jasper bricks than xenon power bricks.

[strapmonkey]

Shaggy, that also is true.  The Xenon was, what 90 nm, then 90 on the GPU and 65 nm fab for the CPU when they went to Falcon, then the Jasper was 65 nm for both.  MS had a pretty tall order trying to cool 90 nm process parts in such tight confines.  It got progressively better when they started to shrink the dies and, as a result, cut power consumption.  They spent more on the 2nd gen GPU sinks than on the 1st gen jobbies, but they saved a bundle (relatively) when they switched to the 2nd gen CPU sinks, and by then a 220 gm aluminum extrusion on the CPU was plenty.  Not to mention higher yields with a smaller process helped production costs as well.

I'm still running a Xenon power brick on my Jasper because I'm pulling more than spec off the 12v fan header.  Honestly, I don't know that it helps, but it SEEMS like it would.  I've got a 120mm Scythe pulling .41 amps as an exhaust and an Evercool 80mm fan blowing across my CPU sink and it pulls .38 amps or something along those lines, for a total (in theory) of .79 amps from that header.  I don't know if the fan header on a Jasper board will supply that much juice.  Does anyone know the electrical specs off hand?  I'm also never really certain if those are "cranking" amps, or average current draw.  I seen some speculation that a lot of fans wind up pulling less than stated amps.

[Iacon]

here's the link to the xbox 360 with dual noctua tower heatsinks,
http://www.silentxbox.com/xbox_eng.php

i wouldn't mind doing this but each noctua sink is about $70 bucks. My money could be better invested in a water cooling mod.

could you post pictures of your setup strapmonkey?

[mikesnowdon]

QUOTE

could you post pictures of your setup strapmonkey?

I would also like to see this.

[strapmonkey]

I have been away from desk for....yikes, months.  Time flies when they foreclose on your home.  Moving on.  I don't know if anyone is still looking in on this post.  I said (much) earlier that I would post some pics, then totally forgot about it.  I'll strip my box down in a minute and get some pics for youse guys that were asking.  I apologize for teasing then not pleasing.  Bear with for one more dayish.

[Weirdjerz3y]

Damn your home got foreclosed? That really sucks, im sorry to hear that. But in this economy in the us, im not surprised to see a foreclosed home, i see them everywhere, people without jobs, or problems and end up losing their home. So sorry man, as in for the pictures. I would love to see pics.