CKeichel said:
Apart from the higher clock speed, in which extend do you think is the Cortex A8 processor used in the Pandora faster then the one used in the Caanoo/Wiz? I think the implemented PowerVR is indeed faster, then the Caanoos (at least it has more features like OpenGL 2.0 or DX10), but the CPU seems pretty comparable to me. As long as the Caanoo is overclocked. But I agree, I don't see a DC emulation (at least not with sound) on the Pandora either and I think the faster GPU would put the Pandora here in front of the Caanoo.
At the same clock speed Pandora's Cortex-A8 is much faster than Wiz's ARM920T. That's because it is:
- Dual issue superscalar, ie can execute two instructions simultaneously, vs the single-issue ARM9
- Has 256KB of L2 cache, this is really huge.. if you look at some numbers of software ran on Pandora with cache disabled they're much slower than with it enabled
- DDR SDRAM is all around wider at 32-bit instead of 16-bit
- Has branch prediction which makes taken branches 1-2 cycles (depending on fetch) instead of 3 on ARM9. On the flip side mispredicted branches take 13 so for some software branches will be slower..
- Has additional instructions, primarily in ARMv6 and NEON.. you usually have to see a program specifically written for it to make a big difference but when it is it can be huge
The L2 cache is probably the single biggest advantage. It's not fair to just compare clock speed between CPUs released several years apart, Cortex-A8 is a full two generations ahead of ARM9.
I'm sure in terms of raw throughput SGX530 is a lot faster in OpenGL 1.1 too, although I don't know just how big of a gap there is.
EDIT: Meh, ninja'd ;p Forgot the FPU too. I'd hardly call it "somewhat" of a difference myself, we've been seeing reports that are more like 2x at same clock..Not surprising when you look at how badly performance usually scales with clock speed when going from GP2X to Wiz, it really needs L2 cache.