I have passed an order for a "Flirc Raspberry Pi 4 Case". I just received it yesterday.
With this new case, I am now at 41°-43° C at IDLE* (versus 73° C with a original RPi 4 case + passive cooler on CPU, RAM, Chipset's) and at 55°C max on full screen Youtube video (@1080) Chromium player (versus 85° C with a original RPi 4 case + passive cooler on CPU, RAM, Chipset's).
On stress test CPU at 100% I'm at 58 °C maximum with this new case
Although I have not tested it, this case certainly offers a high overcloking potential...
It should be noted that I used a thermal pad brand Alphacool (11W/m K, thickness 1,5 mm) instead of the one supplied original with this case.
This case is the best one for my... The Raspberry Pi Foundation should have sold us a case of this type there and not a completely ineffective plastic case. Because the RPi 4 slowed the speed clock of the CPU as soon as the temperature is too hot (81 ° C seems to me).
I wish a lot of pleasure to all who bought it like me, because the RPi 4 is a great microcomputer.
I look forward to the release of the 64-bit version of Raspbian, which should improve the CPU's computational performance, bring 4K video support, and compatibility with 64-bit softs like Opera, Google Chrome, etc.
Best regards at all.
* with passive cooler on RAM and Chipset's)