How performant is this - are we able to achieve similar speeds as an actual 68k Mac on embedded hardware?
iamflimflam1•2h ago
The P4 is pretty high spec with a 400MHz dual-core RISC-V
vardump•2h ago
At 8 MHz, a 68k can execute at most 2M instructions per second. So the answer is going to be yes, if this manages to execute one 68k instruction per ~200 cycles.
I think executing an instruction is going to be closer to 20-50 cycles than 200, so it should be much faster than a real 68k CPU.
I think performance is likely to be in the ballpark of a 68040 @20 MHz, but that's just a guess. This would leave 20 cycles for each emulated instruction. With JIT you could reach 200 MHz+ comparable speeds.
rasz•1h ago
Everything is coming from PSRAM including frame buffer (at 15 fps) so performance is going to be abysmal.
vardump•15m ago
You should be able to cache hot code and data in the SRAM. Although it'd significantly increase complexity.
anthk•2h ago
VMac would be lighter.
bArray•2h ago
Looking at the M5Stack Tab5 IoT Development Kit [1] based on the ESP32-P4 - it's a really nice piece of kit.
swiftcoder•4h ago
iamflimflam1•2h ago
vardump•2h ago
I think executing an instruction is going to be closer to 20-50 cycles than 200, so it should be much faster than a real 68k CPU.
I think performance is likely to be in the ballpark of a 68040 @20 MHz, but that's just a guess. This would leave 20 cycles for each emulated instruction. With JIT you could reach 200 MHz+ comparable speeds.
rasz•1h ago
vardump•15m ago