Hi,
You can indeed operate on the main thread and to process that in a second gpu.
Even if I didn’t a proper profiling from my experience it may be worse to pre process them as the dimensionality is usually way higher. For example in my case an wavelength of 16k elements becomes into a 512x256x2.
Anyway I only recommend this is the main workload is the stft.if you have additional heavy preprocessing multiprocessing may be better