Don't buy extra RAM, it won't help. This conversion process is just a draft in Beta3 and will be optimized in Beta4, maybe your hardware will be good enough
I've already updated the basic HDR10 conversion in my internal beta4 preview build, but since it's heavy on the GPU, I think low end chips like the N100 won't handle it, but we will see after the rebuild of the pipepline. In the next release Beta4 the performances and optimization will not moved we will be close to the R1.0.0 stable. Important point, in Expert mode, tone mapping is managed by the rendering engine in LE, so be sure to disable tone mapping on your TV/projector.
Determining whether a CPU/iGPU is powerful enough is tricky. Performance relies heavily on the rendering engine in the GPU, which is hard to benchmark, and other limiting factors are still not perfectly understand.