A number of us have had similar issues where RaceRender doesn't seem to improve rendering times on new hardware as well as similar video editing programs:
https://forum.hptuners.com/showthrea...l-cpu-capacity In that thread, Weston's advice was not to confuse CPU usage with useful work which is a valid point. If two programs render a video in the same amount of time, but one program only uses half the CPU and the other uses the entire CPU, then the second is definitely less efficient. However, you could also argue that there is some other bottleneck that is a limiting factor that could be improved to reduce the time even further (given that none of the hardware seems particularly stressed).
I would highly recommend making sure that any videos are stored on a Solid State Drive to ensure that data can be read as quickly as possible by the program (you definitely don't want to be reading from a flash drive or memory card as those will be much slower). RaceRender does seem to use the GPU for some form of encoding, but it seems to rely more heavily on the CPU (at least more so than other video editing programs). I'd recommend closing any other programs and not multitasking while rendering.
You're likely already doing those things; so other than that...we just need to hope some optimizations come in a future release. My own videos tend to be only about a minute long; so my rendering times are generally pretty short. Others render full track sessions which I'm sure take much longer.