Discussion Low Profile GPU heatsinks - which design is better?

[nightshift]

After checking out what kind of low profile gpu's are there to choose from these days, I narrowed it down to two contenders:

• Gigabyte 4060 LP - outstanding performance, great cooling design with triple fan and heatpipe. 115w TDP, requires a 6+2pin connector. Cost is 300$.
• ASRock A380 LP - moderate performance, okay-ish cooling design with dual fan and no heatpipe. Merely 45w(!) TDP, no power connector. Cost is 100$.

For the price, both seems pretty amazing. I have a 12400T which have a 35w TDP and could make a really powerful all Intel, all ASRock setup for just 100w of total consumption with the A380 pretty cheap. But the cooler design left me wondering on a separate question.

The fins of the Gigabyte card are a LOT more dense and thinner, while on the ASRock's model, it's much more scarce and thicker. I suppose the more expensive card have the better cooling solution, but what is the physics behind this? I currently have an ITX gpu that have a rev1 version with denser fins while the rev2 is more breezy. Back when I got it, I went for the rev2, thinking it's the more advanced model. Was that the right choice?

 

[robbee]

It's all about surface area to dissipate heat.

The ASRock heatsink is a solid piece of extruded aluminium. This is a very cheap way of mass producing heatsinks but doesn't allow for very thin parts, thus there is less surface area. You generally see these heatsinks on the cheapest and/or lowest power cards.

Gigabyte uses stamped fins that can be much thinner and wrapper around a copper heatpipe. This method is more expensive but allows for much more surface area.

While denser fins give more surface area, you will also need more static pressure to force air through the heatsink. Manufacturers will always search for the best balance between static pressure and fin spacing. But generally speaking, without taking the fan into account, more surface area will always result in better cooling potential.

 

[k0n]

While denser fins give more surface area, you will also need more static pressure to force air through the heatsink.

That's why something like the Arctic 17 LP can be quieter than the Noctua NH-L9... as long as it isn't overwhelmed.

The Noctua needs a higher minimum RPM to get any air through the finstack, but the Arctic has a much lower maximum cooling capacity because it is lacking surface area.

Extruded aluminum has it's place and can even be beneficial, but when it is used it is often just because of the lower cost.