

The area of radiator needed directly corresponds to the amount of power harvested by the solar panels. It doesn’t matter what the load is. So a compute frame with the same amount of solar panels as the space station would need approximately the same radiatot area as the ISS, unless you are bringing nuclear power into the mix.
I agree that space based datacenters are a bad idea, but the thermals really are not the gotcha people are making them out to be.
Thermal energy is primarily dissipated as infrared light which moves at the speed of light. There is no way for space to accumulate heat. If that were the case the entire solar system would be unlivable. The IR emitted by satellites is truly negligible in comparison to the electromagnetic radiation emitted by the sun.