Der8auer tested two very unusual cooling solutions from Aliexpress aimed at reducing the surface temperature on the backplate of the Best Graphics Cards. However, upon testing with a Gigabyte RX 6900 XT, he found both coolers underwhelming in their execution and provided no tangible improvements to graphics card temperatures.
Backplate cooling is nothing new, but the cooling devices Der8auer showed off are very unusual, being very big and bulky devices with active cooling. This is incredibly overkill for most graphics cards since the backplate (generally) does not house any high-wattage components that would require beefy coolers. The only exception would be the RTX 3090 (non-Ti), which features half of its GDDR6X memory ICs on the rear of the card. But even in this case, passive cooling from a backplate is generally good enough unless you're looking into memory overclocking.
The first cooling unit Der8auer tested was made entirely out of copper, comprised of two fans installed inside a copper heatsink — made out of 5 large copper sheets stacked on top of each other. The installation mechanism involved zip ties and tape to "securely" mount the cooling device to the GPU backplate.
The next device is even more strange, with a very unusual L-shaped design featuring three very long heatpipes connected to a distribution plate on one end and a heatsink on the other. Der8auer reports that instructions did not come with this model, but apparently, the device uses the same zip tie mounting mechanism as the former device since there are no screw holes or any sophisticated cooling mounts located on the device whatsoever.
In testing, Der8auer found that both cooling solutions did not live up to expectations, only dropping backplate temperatures on a Gigabyte RX 6900 XT by 5C and 8C, respectively. Even worse, both solutions did not drop GPU temperatures at all, providing no tangible benefits to GPU longevity or performance.
The thermal results demonstrated by Der8auser are probably why exotic backplate cooling is not popular in the DIY space. Not only are the devices usually unnecessary, but they also provide next to no tangible gains at all. If you really need cooler thermals, you would be best served with a liquid-cooled GPU block designed specifically for your GPU that can cool both the bottom and the top of your graphics card if necessary.
I think a simple measurement of backplate temperatures should be the first clue as to whether better cooling could be worthwhile.
Stopped reading right there.
I've used regular heatsink compound on loose heatsinks that I know will remain level (e.g. Raspberry Pi, DVD player, etc.), and it's been fine.
If you want the best cooling for the PCB back-side though, the best option is to rip the backplate off and have a fan blow air across the bare PCB: the SMDs have more total surface area than what the thermal pads can touch and you eliminate the thick thermal pads' relatively high thermal resistance altogether.
66c for mem temps under mining benchmarks, although the active plate came at later date and didn't want to take things apart for that.
my 3090 Frankenstein mod :cool: