Now we will move on to a protracted section about thermals and fan speeds.
During the 10x iterations of the Metro Exodus benchmark (3440×1440, extreme preset) our RTX 4080 Founders Edition sample was a very cool-running card, and the fans were not noticeable over CPU cooler noise. These 40 Series Founders Editions are very quiet cards, and at some point I will have to implement an ultra-quiet (or passive) CPU cooling setup to allow for accurate GPU noise measurements.
The RTX 4080 FE registered a max 60.6 C GPU Temperature, and 70.7 C Hot Spot, as reported by the card and captured via GPU-Z data logging. The room during these tests was just under 19 C (~18.8 C), which is a few degrees cooler than our RTX 4090 FE testing (~21.5 C ambient), so looking at deltas makes more sense.
Comparing delta temps, then, we find that the RTX 4080 FE produced a max of 41.8 C GPU / 51.9 C Hot Spot, while the RTX 4090 FE produced a max 45.5 C GPU / 55.3 C Hot Spot. These slightly cooler temps make sense considering a smaller, less power-hungry GPU is being cooled with a thermal design created for the RTX 4090 FE’s big 608 mm^2 GPU and 450W TGP.
Please note, however, that the RTX 4080 FE’s use of this cooler will differ in that the fan speeds are lower by default, since it has less of a thermal load to contend with. I recorded a max fan 1 speed of 1421 RPM, and max fan 2 speed of 1326 RPM from the RTX 4090 FE under load. This RTX 4080 FE, on the other hand, had a max fan 1 speed of 1275 RPM, and max fan 2 speed of 1223 RPM under the same conditions.
Not a huge difference, but still about 10% lower fan speeds on average and slightly better temps.
