Actually the speeds are not too surprising. Just looking at clock speed, In raw PASM you'd expect an 80 MHz Propeller to be 10-12 times faster than a 7.5MHz 286. LMM adds about a 4x overhead, but GCC uses fast cache to hold small loops in COG memory so the speed on such loops approaches that of raw PASM. Moreover, the Prop is 32 bit, so some operations that require multiple instructions on a 286 will be done in just one instruction on the Propeller. So yes, the dhrystone results are reasonable (and moreover are accurate -- you can do the timing by hand to double check this).
Yes after studing the results of newer CPUs it's quite possible. They have millions of dhrytsones per second while we have thousends.
Why not just multiply by 8 for LMM, if we need a high number for the Prop, it's anyway very theoretical. ;-)
Andy
I think it would be more interesting to thread the code, so it actually runs parallel, then take the results from that. It would be more indicative of the true performance, instead of just x8.
Comments
Yes after studing the results of newer CPUs it's quite possible. They have millions of dhrytsones per second while we have thousends.
Perhaps we should adapt this benchmark to compare with other microcontrollers:
http://www.ecrostech.com/Other/Resources/Dhrystone.htm
Andy
I think it would be more interesting to thread the code, so it actually runs parallel, then take the results from that. It would be more indicative of the true performance, instead of just x8.