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"thermal armor" PCF (chipset) fan : bad design? must remove & replace?

URIZEN
Level 7
so there's this old mainboard I got for a bargain (never been used) and I wanna know :

WHAT HAPPENS WHEN THE PCH FAN FAILS?

my mainboard's PCH has this "protection" :





basically it's a small heatsink with a fan & all covered by plastic



now they call it "thermal armor"

but logic says it's more like a thermal trap because:

1) it all depends on the fan, and the fan will fail (small fans are designed to fail)

2) the plastic cover will act as an INSULANT since air's no longer blown up when the fan fails

3) NO HEATPIPE (unlike the Rampage boards) so cannot evacuate the heat out of the PCH heatsink, when the fan fails: the heat remains trapped under the plastic cover


in other words when the fan fails this protection becomes the opposite of a protection


so this smells of planned obsolescence right? they designed this to fail & damage the board by frying the PCH


so should I remove this whole thing (the plastic along with the heatsink & fan) and just put a bigger passive chipset heatsink instead?

like this one:


at least it's "open" (not smothered by plastic) and doesn't depend on a fan
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11 REPLIES 11

Korth
Level 14
Motherboard heatsinks have gotten a lot more elaborate in recent years. And ROG's "Thermal Armor" was once great but it is not (in my opinion) very functional on the latest motherboards. The stuff is designed with a balance of form and function which has been shifting more towards the look of the thing and farther away from the efficiency of the thing.

Some reviewers offer their results and commentary about how well (or not well) specific mobo fixtures actually perform - it varies from product to product. There's very few products which perform awfully, these heatsinks do perform their intended job well enough in most conditions for most users.

But yes, industrial heatsinks are always going to be more efficient (as long as they get some airflow, anyways). Although they obviously don't look as slick, they don't readily accommodate waterblocks, and they might be dimensionally incompatible with other items mounted in the system. To be honest, if you're entirely unconcerned about the gamer looks and styling and bling (and RGB madness) then you'd probably be better off getting enterprise-grade hardware which already builds entirely around proven industrial components.

As far as fan failure goes ... it can and will happen to any kind of fan. The fans built into the mobo are probably high quality, maybe just as good as enterprise-grade counterparts, but your motherboard is used (and at least around 5 years old) so if you want to replace the fan with a ducted system or Noctua or something that's okay ... a high-quality replacement may not improve quality or longevity but it won't hurt. PCH components need to be cooled but not quite as aggressively as CPU/GPU components, while VRM components usually don't even begin to de-rate performance until they hit around 125C.

If you install a completely DIY heatsink solution then you'll have to figure out some method of proper mounting and proper thermal interface, be prepared to do some minor modifications to your metal if you want to use the motherboard's fasteners.

I don't know what's under that block on your motherboard, but if it's RF-sensitive stuff (like audio) or RF-emitting stuff (like WiFi) then it's often best to not tamper with the manufacturer's original design.
"All opinions are not equal. Some are a very great deal more robust, sophisticated and well supported in logic and argument than others." - Douglas Adams

[/Korth]

ok thx for the reply

but considering this specific mainboard & cooling system (the one in the pic: heatsink covered by plastic, no heatpipe leading out of the heatsink, tiny fan) the question is what will happen when that fan stops spinning?

I mean once the fan stops working...then the so called "thermal armor" essentially becomes a thermal death trap right? the plastic seals in the heat & acts as an insulant with no heatpipe to evacuate the heat outside and (when fan fails) no fan to blow out the hot air


ps. also over here, this blue Zalman heatsink is the only one I found. no noctua PCH heatsink as far as I could find (I'm in old europe - not much available here)

Korth
Level 14
When the fan stops spinning the forced airflow on the heatsink will halt. The heatsink is covered so without forced airflow it won't work very well at all, it will actually trap heat because it can't radiate very well and isn't open enough for natural air convection. Basically the same thing that happens to a watercooled system when the pump fails, the heat has nowhere to go. The part will either run hot (with throttled performance) or it will overheat enough that hardware/firmware sensors will trigger a forced shutdown. Worst case extreme (all the failsafes fail catastrophically and the silicon substrate breaks) is technically possible but also extremely unlikely, not realistically worth worrying about.

Which is why enterprise-grade hardware avoids covered heatsinks and prefers industrial designs, along with redundant (and hot-swappable) fans to force continuous airflow. The downside is that they look ugly and eat power and tend to run loud, not the sort of thing most people want to have in their home computer.
"All opinions are not equal. Some are a very great deal more robust, sophisticated and well supported in logic and argument than others." - Douglas Adams

[/Korth]

Korth wrote:
When the fan stops spinning the forced airflow on the heatsink will halt. The heatsink is covered so without forced airflow it won't work very well at all, it will actually trap heat because it can't radiate very well and isn't open enough for natural air convection.

thx a lot

so that basically answers my question then: their so-called "thermal armor" is a thermal trap & a blatant lie (any system that relies exclusively on a tiny spinning fan, is not a protection but a time bomb)


I'm gonna replace that s--- ASAP

1- do you think the blue Zalman heatsink I put in the 2nd pic, would be a good alternative? it's a passive cooler of course but then so it the heatsink on the p9x79 (passive heatsink, no heatpipe, no plastic & no fan)

cause that's all I got ATM


2- just one more question: SUPPOSE that the heatsink under the plastic, had a heatpipe going out of it to an exterior secondary heatsink outside the plastic cover (exactly like on the Rampage IV extreme board): would the - now passive - cooling still be somewhat effective despite the absence of a fan?



ps. and again thx for your time man

I can't answer your question about that heatsink. The answer depends on the specific dimensions of the part(s) you're covering. But heatsinks are available in countless sizes and shapes. And from countless manufacturers (who, more often than not, do not exclusive sell to PC/gaming markets), you're as likely to find compatible parts on mouser or digikey as on a Zalman or Corsair website.

Heatpipes are incredibly efficient heat transfer devices, when properly chosen/designed/built for the intended application. They're great if you need to move a lot of heat from a small area to a large heatsink/radiator (and thus multiply thermal-radiating surface area), especially in a confined physical form factor (like a laptop). They wouldn't do much of anything useful under thermal armor, lol. Any heatsink (with or without integrated heatpipes) which fits on your part would work well enough. And it doesn't even have to be something bigger than the built-in heatsink unless you intend to operate it hotter and heavier than ASUS allowed. In practice, the best upgrade you could do to this cooling (which doesn't even need to be upgraded) would be a waterblock.
"All opinions are not equal. Some are a very great deal more robust, sophisticated and well supported in logic and argument than others." - Douglas Adams

[/Korth]

Korth
Level 14
The earlier iterations of Thermal Armor (circa Sabertooth Z97) did measurably improve system temps, I think they had an integrated fan.
The last iteration I'm familiar with (Maximus IX Code) didn't really impact temps either way, it was just a cool-looking decorative feature.
Like I said, it varies from product to product. If you can't compare the products directly then you have to read reviews from someone who did.

It's actually a good approach to managing temps - basically an enclosed section which keeps the main PCB cool - if there's forced airflow under the armor. It can be very useful if you have non-blower-style GPU cards or non-reference GPU cards with "improved" coolers - these tend to be designed to cool the card itself at any cost, they just push hot air off, some hot air gets expelled out of chassis but a lot of hot air just spills over the card edges and onto the motherboard (indeed, around the parts of the motherboard which need the most cooling).

So you could somehow install a fan or two (intake and exhaust) under the armor, essentially making it into a ducted airflow system. Maybe add some dust filters, lol. The downside is that anything not covered by the armor (like RAM and mobo VRM/PCH heatsinks) will also need to be given some airflow.

Or you could do what I did, just remove the whole thing, so that existing chassis fans cool the motherboard along with everything else in the compartment/system.
"All opinions are not equal. Some are a very great deal more robust, sophisticated and well supported in logic and argument than others." - Douglas Adams

[/Korth]

Korth wrote:


It's actually a good approach to managing temps - basically an enclosed section which keeps the main PCB cool - if there's forced airflow under the armor
but that's the problem: it's a HUGE "if"

ditto for watercooling: it's an active system and waterblocks are about as reliable as small-size fans (I read too many horror stories about them)

as for the blue heatsink I mentioned: this is the PCH on the sabertooth x79 once the armor is removed:

http://images.hardwarecanucks.com/image/eldonko/X79SABERTOOTH/Board/Layout.png

http://images.hardwarecanucks.com/image/eldonko/X79SABERTOOTH/Board/chipset.jpg

(so the PCH itself (the shiny metal part) is a bit over 1cm in size)


and so you dont have to scroll all the way up here's my new PCH heatsink again:

http://images.highspeedbackbone.net/skuimages/large/Z20-4000-main.jpg

(btw I got it second hand from someone - I don't buy on internet)

so what do you think will that blue zalman heatsink be a good alternative to the armor, for that board?

ps. I don't plan to overclock

but here's another question, does overclocking increase PCH temps? cause PCH temps appears to be the same whether it's on idle or under prime95 (only cpu temps go up)

actually what DOES make PCH temps go up? prime95 seems to have little effect

Korth
Level 14
Overclocking does increase PCH temps if it increases PCH workload. Cards, drives, USBs, and other hardware (including ASUS chipset add-ons) all load through it, faster memory speeds and CPU clocks allow (force) more data to flow through it, it gets hotter. Maybe CPU-intensive stress like Prime95 don't have much impact on the PCH, but moving data across all the lanes and interfaces (multiple simultaneous transfers on all drives and USBs and cards, etc) does warm it up.

The horror stories about failed liquid cooling (halted pumps, leaky fittings, corroded blocks, etc) are real but I think much exaggerated. And they mainly affect DIY loops - closed-loop AIOs are basically just as watertight as sealed heatpipes, they just "never" leak unless they're somehow damaged. Stopped pumps are basically the same deal as stopped fans - they'll make your system overheat until it exceeds safe temps and forces immediate shutdown - replacing one with the other doesn't increase safety margins.

You basically can't use pure passive cooling on the PCH, it just won't be enough. So you're basically stuck with active cooling - fan, pump, or even TEC if you want a little exotic overkill - and it hardly matters if the moving parts which force airflow (across a heatsink, through the chassis, or across the rad) are located one inch away or one foot away, if they stop moving the results are the same in every instance.

So I honestly don't feel you'd gain anything from upgrading the built-in heatsink. Especially if the PCH never seems to heat up anyhow. I couldn't say if that Zalman part is compatible without physical comparisons - but it'll have to cover the same thermal contact area, have the same mating geometry, the same mounting pressure, and compatible mounting hardware as the part it's intended to replace.

I can understand your apprehension about the built-in fan dying ... even though it's extremely unlikely to cause any permanent hardware damage (other than the fan itself being dead) ... I think the best solution would be leaving it as-is, "moving the fan out" with ducting (ie: a tube connected to a fan somewhere else), or installing a waterblock specifically designed for that motherboard. Anything else is more easily answered as a "hands on" DIY make-it-work project than on the internet, unless you can find somebody else who's already figured out the specific mod for you.
"All opinions are not equal. Some are a very great deal more robust, sophisticated and well supported in logic and argument than others." - Douglas Adams

[/Korth]

Korth wrote:
You basically can't use pure passive cooling on the PCH, it just won't be enough
what about this board:

https://ae01.alicdn.com/kf/HTB1LqrNe2Qs8KJjSZFEq6A9RpXa6/Asus-P9X79-Desktop-Motherboard-X79-Socket-L...

only passive heatsink (bigger but no fins so low surface area), no heatpipe no fan