Testing a 6200 and comparison with 6100

[zigzagjoe]

You might want to peek at the assembly coming out of your PPC compiler. Perhaps it's unoptimized or unusually bad. Hand-written assembly probably would make more sense to sidestep compiler shenanigans and improve accuracy.

 

[David Cook]

What speed does the 040 L1 run at? 33 or 66MHz? (I assume 33, but sometimes worth asking the dumb questions).

According to me, 33 MHz. According to Apple and Motorola marketing department 66 MHz.

 

[David Cook]

Perhaps it's unoptimized or unusually bad.

Agreed. That wouldn't surprise me. That's my big caveat to all of this. I'm using a period-correct compiler (Metrowerks CodeWarrior 11 Gold) with pure C code that is not specifically tailored for a PowerPC processor. I am positive that if I wrote this code differently and chose 603 instruction ordering it could do better.

As you know, the cache tester is really simple. It's purpose is just to detect the existence of a cache at various steps. It doesn't exercise the cache with writes or random accesses. And, it is focused on data, not code.

 

[Phipli]

According to me, 33 MHz. According to Apple and Motorola marketing department 66 MHz.

Fair, just double checking given the performance difference.