I recently bought an n100 and within a matter of days got buyer's remorse and impulse-purchased an n305 to go right beside it, which is currently sitting with a wildly overpriced 48 GB stick installed and 2TB SN850X, it's an absolute joy perfwise and the absence of heat it generates.

The only thing I'd reserve judgement on is the tendency to throttle. I haven't got far enough to characterize it, but it's not clear how much value those extra cores will add over the n100 with TDP settings tweaked down in the BIOS, and if leaving the n305 to run at max TDP, heat/noise/cost/temperature-related instability may start to become an issue, especially when packing other hot components like a decent SSD into the tiny cases they come in.

It really matters very little that RK3588 has 8 cores, because the Cortex-A55 cores are very weak.

The reason why RK3588 may beat N100 in multi-threaded benchmarks is that the latter has a very low base clock frequency, due to the higher power consumption when all the cores are active. N100 needs a better cooling than RK3588 in order to reach its maximum possible multi-threaded speed. With good enough cooling that will prevent the drop in clock frequency, N100 will beat easily RK3588 in any benchmark, because the Intel Gracemont cores have a speed similar to the Arm Cortex-A78 cores and much greater than the Cortex-A76 cores of RK3588.

It should be noted that Radxa X4, due to the constraints of the credit card size, has only a 32-bit DRAM interface. So its -4800 memory is equivalent with a -2400 memory of the bigger N100 boards, which use a 64-bit DRAM interface. The good RK3588 boards also use a 64-bit DRAM interface (with a somewhat lower speed, e.g. -4267), so they may win in benchmarks that are limited by memory bandwidth.

However in the applications in which I am interested for such a small board like Radxa X4 (like a network router/firewall or a controller for some custom hardware) the performance is almost always limited by the speed of the peripheral interfaces, so Radxa X4 will be better than any existing Arm-based SBC.

While I haven't benchmarked, my reasoning is that for parallel workloads (especially VMs but also containers), penalty from context-switching should be vastly reduced by even those slower cores.

The RK3588 doesn’t beat the N100 in anything but throughput - I have been benchmarking a number of SBCs lately to consult on building custom industrial edge devices and in terms of bang for the buck and PCI lane availability (as in actually accessible lanes) the Rockchip designs work out a little cheaper. I have one of those 4xNVMe NAS boards to test next, and expect it to be pretty snappy for the same wattage-but it all depends on the use case.

(I also have an X4, am waiting for an SSD for it for proper testing)

Good luck getting timely mainline Linux support if ever. Rockchip usually provides an ancient patched kernel without much willingness to upstream their changes. They usually leave things for the community to sort out. On the other hand, x86 has the best mainline support which you can count for awfully long time to be around.

There are projects (like Armbian) working to improve that situation, but they can always use more help.

https://www.armbian.com/newsflash/armbian-needs-your-help/