I don't know about HPC2000 ARM
(like MP900 or Jornada 720
)
But:
I can get 2GB maximum on Windows CE 2.0 MIPS for my MobilePro 700
8GB maximum on Windows CE 3.0 MIPS for my MobilePro 790
And 32GB maximum on Windows CE 4.2 XSCALE/ARM for my MobilePro 900
https://www.hpcfactor.com/support/cesd/200205/maximum_supported_memo...
Now:
I also read somewhere that there's some kind of storage driver for HPC2000 ARM that may assist in higher capacities, but I can't remember what HPC:Factor thread that was.