Raspberry Pi 4 Will Probably Need A Fan No Matter What
The Raspberry Pi 4 makes giant leaps that almost make it a usable ARM-based desktop single-board computer, at least on paper. In practice, however, those may have been leaps of faith that the RPi Foundation is also asking new owners to make. With great power comes great responsibility, as the cliche goes, but in the Raspberry Pi 4's case, that comes with not so small sacrifices instead, including one that could prove to be dangerous for users.
The RPi 4 is the most powerful Raspberry Pi ever. While it may not match some SBCs that are specifically designed for power, the jump to a quad-core CPU and 4 GB RAM max does raise its profile a bit. That, however, does mean that the RPi 4 also generates a lot more heat than any other RPi before it.
Unfortunately, it seems that the old board design may no longer be able to handle the heat. Developer Jeff Geerling noted how the board can get hot quickly even during idle periods, partly due to the USB-C port which also generates more heat than the previous micro USB power source. All that heat means that the RPi 4 can throttle quickly and might be too hot to hold even.
It's not a lost cause though, even if the Foundation's official RPi 4 case turns it into what Geerling describes as a plastic oven. Installing fans, not just a heatsink, could alleviate those issues. That does mean, however, that a fan is now more than just an optional accessory.
The RPi 4 recently received criticism for its non-standard implementation of the USB-C spec, which has resulted in incompatibility with spec-compliant cables and chargers. Co-founder Eben Upton promised to fix the USB-C issue but it's hard to imagine how the thermal problem can be fixed without a significant redesign of the board and breaking compatibility with previous designs.