Question Why no fins on VRM heatsinks nowadays?

[Craig C]

I've been looking at Asus Z390 boards, but other brands are similar. The VRM sinks have no real fins, more like a few grooves. What hapenned to the importance of surface area? (Asus WS Z390 Pro pics below.)
(Click for Hi-Res)

I'm aware that chipsets do not get as hot as they used to, du to their high-speed functions being moved to the CPU, but what a bout VRMs?

Theory: Maybe VRM temps "spike" much more than a CPU's. Then, extra mass & heat capacity of a sink would be more advantageous than heat conductance. The extra mass would smooth out spikes, but convecting it outwards slowly. Yes I'm reading a physics textbook. Sawing more grooves would remove mass. But skiving or extrusion would not, yet still no fins?

 

[Mr Evil]

The MOSFETs and other parts used in the VRMs have improved a lot, making them more efficient than they used to be. They barely need heatsinks at all, leaving the motherboard manufacturers free to design heatsinks that look good rather than ones that cool well.

 

[Kocicak]

This very question has been bothering me for ages. The power delivery coolers on consumer motherboards are just a showpiece of graphic design over functionality, of a waste of material and energy. You could make conventional heatsinks which cool better with a fourth of the material they use for these horrible things.

 

[ao_ika_red]

I would trade all those RGB for the return of proper copper heatsink.

 

[Craig C]

I would trade all those RGB for the return of proper copper heatsink.

^^^^^^^^^^^^^^++++++++1!
Dont forget the IO shroud! Tar and feather that employee.

 

[Kocicak]

The heatsink on the new Asus X570 WS board looks much better though.

 

[killster1]

pretty sure the only reason the heatsinks are small is to fit giant cpu coolers. I feel like the board would be limited to what type of cooler if the heatsinks are to big or heatpipes going around. Ya i love the heatpipes always they are a great idea and DFI had great looking / functioning heatsinks / heatpipes. Maybe they should make two versions a water cooling version and air.. (water would have big heatsinks since cpu heatsink wont be getting in the way)

 

[Furious_Styles]

I would trade all those RGB for the return of proper copper heatsink.
View attachment 6706

I've looked at several of the old 775 ones recently and I agree the copper looks great.

 

[UsandThem]

I imagine why so few companies use more copper than is necessary has to due with it's pricing increase over the years.

Everyone knows copper conducts heat way better than aluminum, but it is also much more expensive. It's probably also the reason why Intel OEM coolers rarely have a copper core anymore as well.

https://www.macrotrends.net/1476/copper-prices-historical-chart-data

 

[mindless1]

It has a fin, just not very many slits in it. They wanted it to look sleek and pretty, but also they anticipate air flowing out from the CPU socket then channeled sideways through the fin.

Realize that this is not the primary heatsink. The thermal conductivity of the encapsulation material is very poor compared to the primary heatsinking done through the metal back of the fet to the PCB copper.

The added heatsink is mostly just to keep the epoxy/other plastic encapsulation from exceeding its max temperature and cracking apart, if one is significantly overclocking, and of course to try to justify why a fancy board with $30 worth of extras, costs more than that, a marketed premium product.

 

[Craig C]

Good answers all. I cant wait untill this fad of RGB & IO armor ends.

 

[PPB]

The evolution will be an i/o armor that is the vrm heatsink itself IMO. At least on expensive boards.

 

[ao_ika_red]

I imagine why so few companies use more copper than is necessary has to due with it's pricing increase over the years.

Okay, that explains quite a lot why we didn't see any new Zalman's Copper flower cooler this day.

It's probably also the reason why Intel OEM coolers rarely have a copper core anymore as well.

My stock Athlon (XV) hsf still has copper core and I believe it's still the same with 95W+ Wraith cooler.

 

[UsandThem]

Okay, that explains quite a lot why we didn't see any new Zalman's Copper flower cooler this day.

My stock Athlon (XV) hsf still has copper core and I believe it's still the same with 95W+ Wraith cooler.

Yeah, AMD puts more money / effort into their stock coolers, that's why they are so much better than the all aluminum junk one's Intel ships with their CPUs.

 

[thigobr]

They should do a good mixed copper base/aluminium fins as pure copper has lower thermal capacity (need more mass). Probably cost is the main driver for this regression and it's sad to watch...
Gigabyte seems to be releasing few boards with proper fins but nothing midrange.

 

[gorobei]

vrm heatsinks are a bit of complex balancing.

the older type cpus didnt draw that much power, so the vrm didnt need to be that many phases(i think i saw a s775 conroe board with 2 phases back in the day). now with intel and amd pushing 8+ cores the vrms are 3-4 phases for budget to midrange, 4-8 phases for midrange to low premium, 10-16 for upper premium. the 28 core 5ghz intel monstrosity needed a 20 phase board.

that said, vrm design is like the commutative principle in that there are any number of configurations to arrive at a desired result. a true 8 phase controller vs a 4 phase with doublers will still divide the load and heat among more components. smart power stages instead of basic mosfets can improve your waste heat. it is all a matter of cost. there are mb vrm that dont need any heatsinks because they have a ton of phases and the mosfets are only dealing with a tiny amount of load. there are 3 and 4 phase vrm that need massive sinks because they only have one high side and one low side mosfet. as long as the heatsink is matched to the vrm components it is fine.

the northbridge/vrm heatpipes from those old motherboards are there to route the heat from the nb chipset to the fins/sinks on the vrm which were assumed to be getting downdraft from the cpu cooler fan. the vrm parts didnt need copper fin sinks but the nb did. once the nb was integrated into the cpu, vrm sinks could be simplified.

the reason for the shift away from copper is cost and lack of necessity. aluminum is a way cheaper and lighter material and can be extruded, while copper can not. milling the fins into copper is time consuming, the blades/bits are expensive, the cnc mill is even more expensive. aluminum extrusions just need a chop saw.

there are plenty of extruded sinks with more fins and surface area than the op's example images. covering them with plastic shrouds for branding esthetic doesnt help much, but if the sink is appropriately sized it is fine.

the fans on the x570 boards are likely there because an extruded sink large enough for the heat output of the chipset would likely be too tall and interfere with mounting a long gpu with a large 2-3 slot cooler.

im no fan of the cosmetic plastic shrouds and cover up plates, but the real problem is the atx form factor. at some point mb/ram/gpu/cooler/psu/case makers need to bite the bullet and come up with something new that doesnt compromise airflow and component layout "just because" everyone else is still using a 24 year old standard.

 

[NTMBK]

My stock Athlon (XV) hsf still has copper core and I believe it's still the same with 95W+ Wraith cooler.

That's probably because the Bulldozer family is a hot mess. You need copper just to get decent performance.

 

[ao_ika_red]

That's probably because the Bulldozer family is a hot mess. You need copper just to get decent performance.

Or they're just listening to customer's feedback. Their previous cooler (pre-Carrizo) is garbage, though. It can't handle 95W+ load and the noise is absolutely annoying..

 

[Kocicak]

This is fascinating. Asus has mounted half a kilo (or more?) aluminium ingot on their TRX40-Pro motherboard. It seems that is has almost no fins on the upper side. From the front it has four cuts. What is the purpose of those four cuts? Why are there only four of them? Has the designer of this abomination run out of pencil lead while drawing them or what?!

Why not to make 40 cuts instead of 4 and make this boat anchor three times smaller while cooling better?

BTW, for the enviromentally aware people: this is horrible waste of material and energy too.

 

[mindless1]

^ It's fairly irrelevant. Asus has many years of testing heatsinks, will know the effectiveness and the design make some sense because they're making it taller with surface area parallel to the plane of the motherboard, which is the direction air is usually flowing with a typical vertical heatpipe 'sink towards the back of the case.

Would something smaller work? Sure, but they have to do something to trick buyers into thinking that a dozen or two dollars worth of upgrades over other boards are worth a lot more than that. Maybe it's not a trick, that's just how the luxury market works for most products, that they run out of useful features and start focusing on eyecandy.

 

[IntelUser2000]

This very question has been bothering me for ages. The power delivery coolers on consumer motherboards are just a showpiece of graphic design over functionality, of a waste of material and energy. You could make conventional heatsinks which cool better with a fourth of the material they use for these horrible things.

Yes, its a waste. But motherboards are a low margin business and you need to stand out to gain attention and marketshare from consumers. So manufacturers will do everything and anything to latch onto a new fad. It's like a checklist of features they satisfy for buyers. You miss one and they complain.

And every year Intel/AMD integrates more into their CPUs, the less the manufacturers can do to differentiate. Before with the Northbridge, design of the board impacted memory performance somewhat. Now with integrated Northbridge it doesn't matter. Let's say they integrate the I/O chip into the CPU whether on package or on die. Then all you are left with power delivery and things to accommodate for sockets such as CPU and memory.

What else is there other than to appease the senses by putting fancy well polished heatsinks and RGB lighting?

 

[Markfw]

Here is the best cooling I have ever seen. I would pay quite a bit extra to see this nowadays. Notice the heatpipe goes all the way around all the VRMs, and over to the chipset. Notice the heatpipes and coolers on the memory, and the copper on the base of the HSF ! This is a fully functional socket 775 quad core (Xeon)

 

[EliteRetard]

Here is the best cooling I have ever seen. I would pay quite a bit extra to see this nowadays. Notice the heatpipe goes all the way around all the VRMs, and over to the chipset. Notice the heatpipes and coolers on the memory, and the copper on the base of the HSF ! This is a fully functional socket 775 quad core (Xeon)

QQ I fairly recently had to clear out all my old hardware like this, I had to downsize to a space that can't even fit a bed.
Although my primary computer (one I'm typing this on) is an X6 1100T...so I technically still own some old hardware.

That looks like OCZ Reaper HPC RAM, though perhaps a slightly different variant to what I had.
I also liked the look of their gold mesh version, and I wish somebody would pick up the design for modern RAM.

 

[Kocicak]

It is funny how nowadays motherboard manufacturers treat heatpipe or properly filled heatsinks as a "luxury items" and they put them only on the premium boards.

I am really curious how much does the THING on Asus TRX40-Pro motherboard weight.

 

[Markfw]

It is funny how nowadays motherboard manufacturers treat heatpipe or properly filled heatsinks as a "luxury items" and they put them only on the premium boards.

I am really curious how much does the THING on Asus TRX40-Pro motherboard weight.

That motherbard was like $300, which at that time was ultra-premium.