Can a huge heatsink damage a motherboard?

[Knavish]

I was just looking at the Ars Technica God Box that was published today. They use a 2 socket motherboard with two Thermalright HR-01 heatsinks. Each weighs ~535 grams.

Aren't these attached with the same little heatsink retention mechanisms that any stock heatsink uses? Does anyone ever worry about strapping 1KG of weight to a thin motherboard PCB -- much of it is a good distance from the board for some bonus cantilever stresses???

I seem to remember a picture of some huge heatsink a guy needed to hang from the top of his case to support the weight, so I guess some people have run into this problem already.

Just curious...

 

[Rike]

The bolt though kit mostly takes care of that, but yes you have to be careful. If you have a machine you're going to be moving around a lot, you don't want to be careless if you have have a monster heatsink.

With the particular scenario they set up, it might be prudent to rig a little extra support to take a little of the weight off.

 

[aigomorla]

LOL god box...

I wonder what they would call my Nadeshiko if they called that a god box. :X

Okey.. problem with big sinks... some can strain the board and cause a warp, but this is fixed by the introduction of a backplate.

The other problem u have using a large class sink is improper weight/pressure distribution.
That means u will have uneven temps because your sink will be tempted to tilt down thanks to newton and his messed up laws of gravity.

That leads to incorrect mounts, and off temps.
Usually fixable by tying a string to the top of the case to the sink to brace it.

 

[Zap]

Another possible problem?

 

[cmdrdredd]

The Thermalright Ultra 120 Extreme Copper is a 100% solid copper heat sink that is recommended only if your system is laying flat. If you mount it in a standard case they warm of breaking your motherboard. It weighs 1900 grams

 

[Red Squirrel]

Yeah big heat sinks have always made me nervous, especially if transporting the PC. If you drop it even an inch while laying it down it might be enough force to make the heat sink let go and drop on other components - I've heard of it happen.

 

[cmdrdredd]

Yeah big heat sinks have always made me nervous, especially if transporting the PC. If you drop it even an inch while laying it down it might be enough force to make the heat sink let go and drop on other components - I've heard of it happen.

That's why I like bolt through methods that hold to a back plate. No push pins for me.

 

[aigomorla]

The Thermalright Ultra 120 Extreme Copper is a 100% solid copper heat sink that is recommended only if your system is laying flat. If you mount it in a standard case they warm of breaking your motherboard. It weighs 1900 grams

that sink is ridiculous.

And i honestly thought my ifx-14 was heavy.

 

[Red Irish]

The Thermalright Ultra 120 Extreme Copper is a 100% solid copper heat sink that is recommended only if your system is laying flat. If you mount it in a standard case they warm of breaking your motherboard. It weighs 1900 grams

Just out of interest, what horizontal cases would that beast fit in, or do they simply expect us to lay our towers flat?

I assume that standard Thermalright Ultra 120 owners are not laying their towers flat.

 

[wwswimming]

i worked in a Mechanical Engineering department at Northrop Grumman for about 8 years, working on military avionices (airplane radios). we did a lot of finite element consulting, i split my time between FEA & design & project management.

the basic rule of thumb amongst department members (about 50 engineers) was that a cantilevered load (TRUE120 is the classic example), at resonance, will see loads about 100 times the static load.

in other words, if you ship a computer with one of these GaZonga Large heatsinks and don't restrain it/ fill the cavity with styrofoam peanuts to keep it from bouncing around, sometimes when the truck goes over a bump the motherboard will see transient stresses - as if you had a 100-200 pound heat sink sitting on it on a desktop.

i.e. 1-2 pound cantilevered load at resonance will create stresses similar to a 100-200 pound static load.

it would take a lot of time to predict these things so often we would just design the f*ck out of (make it rugged) and evaluate resonances to make sure we didn't have resonances near each other (make them at least an octave apart, e.g. if the rack has a resonance at 100 Hz, make sure all of our resonance' were 200 Hz or higher)

 

[Zepper]

I have supported my heatsinks by zip ties to something above them and I've never had anything that weighs anywhere near the gigundo crap they are selling these days. Definitely need to pack them separately for shipping.

.bh.

 

[Modelworks]

Also consider that when vertical that heatsink is pulling on the motherboard , flexing the connection inside the layers of the board. Too much weight and over time you can break traces. Only way I would put serious weight on something like that is if it was anchored underneath to the case frame, not the board.

 

[aigomorla]

the basic rule of thumb amongst department members (about 50 engineers) was that a cantilevered load (TRUE120 is the classic example), at resonance, will see loads about 100 times the static load.

yes i know about worries on accidental bumps when moving this system around in the office.

IFX-14, theres a string tied to it to brace it up tho. You guys cant see the string.

 

[cmdrdredd]

Just out of interest, what horizontal cases would that beast fit in, or do they simply expect us to lay our towers flat?

I assume that standard Thermalright Ultra 120 owners are not laying their towers flat.

None lol. There are no horizontal cases that I can find that work. This is for people wanting to try breaking records with their motherboard in open air or those who build some special case around it. To me it seems like the engineers said "hey lets see how a solid copper heatsink is for fun! Hell maybe someone will even buy it for fun!"

 

[Red Squirrel]

I've always thought it would be cool to get one of those old 486 cases with the LCD and turbo button, put in a kick ass dual cpu motherboard with two HUGE heat sinks and have them stick out of the case, kinda like ricers and their motors sticking out of the car hood.

Maybe it's already been done.

 

[aigomorla]

I've always thought it would be cool to get one of those old 486 cases with the LCD and turbo button, put in a kick ass dual cpu motherboard with two HUGE heat sinks and have them stick out of the case, kinda like ricers and their motors sticking out of the car hood.

Maybe it's already been done.

no but they call those cases HTPC boxes.