HP 49G / HP 50G memory

[Han]

Port 0 resides in SRAM and programs run directly off of SRAM (presumably the first two 128KB banks of the 512KB chip). Port 1 is the remaining SRAM. Both of these are equally fast.

Port 2 is FLASH, and programs from here must first be copied to user memory -- usually the same place where Port 0 resides. Then it is run from there. So the only speed hit, really, is the copy phase prior to execution. You would only notice this when running really huge apps (and even then, I am not sure you would perceive much of a difference unless your programs repeatedly call other programs in Port 2).