Providing of course you don't expect it to perform beyond the capabilities of the machine and software. Typical graphic image file resolutions were around 1meg in size at the time.
Is there a RAW file loader for Ifx?
The 25mg file size might be pushing things especially if the G5 chokes. GigaMem might help Think that's what it's called, uses the HD for memory. Would be interesting to try...
No RAW loader AFAIK, but there's a CLI RAW converter on Aminet:
http://aminet.net/package/gfx/conv/ami-dcraw_V8_70Varthall