What makes the Prime so fast?

[cyrille de brébisson]

Hello,

48 was slow because it had a 4mhz, 4 bit CPU with an average instruction execution time of 8 cycles and a very slow memory sub-system.

On top of this, Rpl (sys or not) lead to a lot of memory allocations (and we just stated that memory accesses were expensive on the system).

50 series were slow because they emulated the above system. And, although they had a 70Mhz Arm CPU, emulating a 4 bit system with the ARM is not that easy (not optimal to say the least).

Rpl is actually pretty efficient from a structural standpoint (especially with the PC=(A) instruction!) think about it, it only took 3 instructions to move from one RPL entry point to the next (A=DAT0.A, D0=D0+5, PC=(A)). This is better than any interpreter/virtual machine can do to 'execute the next instruction'...


Prime is fast because it does not have great, modern HW (400Mhz, memory cache, 1 cycle per instruction) and because there is no extra emulation layer.

HPPL is actually not that fast, nor is it memory efficient. It has lots of checks, just like in RPL. It just benefits from a much better HW and memory allocation scheme.

Cyrille