Re: speed values show netsurf 68k SDL is 3-5* faster as OS4 netsurf with same CPU clockrate

Hello On 15.07.11, you wrote: between diffrent CPU and compiler can maybe 20-60% diffrence but the slowdown of OS4 version is 3-5*.thats very large.You dont want compile netsurf SDL Version to see if your use of Cairo slow all down. when i do tests on winuae without JIT, so its very slow i notice, larger window run faster.on 800*600 lots need clip.so i find out, clipping cost more time as render complete page in X. I guess every OS4 machine is run in 32 bit.But i ask the OS4 tester, if he have use netsurf on 32 bit. Use netsurf on OS4 in 32 bit is maybe faster, because the routines need no byte swapping. But on 68k there is in 16 bit alot of byteswapping need.so the compare of 16 bit is valid, because both systems need byteswapping then. The transfer speed to a 68k amiga GFX Card is around 6-12 megabyte /sec and memory copy speed of a 060/50 is around 24 megabyte /sec.So SAM and a Peg have more than 10* more memory transfer speed.so it should at least 10 faster. 68k have lots smaller caches.A big app as netsurf like alot big caches.this is maybe the reason wy the the G4 with the 256 kb secondary cache is so much faster as the SAM. here can see the 16 bit byteswap code the 68k netsurf need do. #if __BYTE_ORDER == __BIG_ENDIAN static inline nsfb_colour_t nsfb_plot_ablend_be16(UNUSED nsfb_t *nsfb, nsfb_colour_t pixel,nsfb_colour_t scrpixel) { int opacity = pixel & 0xFF; int transp = 0x100 - opacity; uint32_t rb, g; pixel >>= 8; scrpixel >>= 8; rb = ((pixel & 0xFF00FF) * opacity + (scrpixel & 0xFF00FF) * transp) >> 8; g = ((pixel & 0x00FF00) * opacity + (scrpixel & 0x00FF00) * transp) >> 8; return ((rb & 0xFF00FF) | (g & 0xFF00)) << 8; } static inline nsfb_colour_t pixel_be_to_colour(UNUSED nsfb_t *nsfb, uint16_t pixel) { return ((pixel & 0x1F) << (8+3)) | ((pixel & 0x7E0) << (8+5)) | ((pixel & 0xF800) << (16)); } static inline uint16_t colour_be_to_pixel(UNUSED nsfb_t *nsfb, nsfb_colour_t c) { return ((c & 0xF8000000) >> 16) | ((c & 0xFC0000) >> (16-3)) | ((c & 0xF800) >> 11 ); } #endif its to see if a port run at full possible speed. I like to see what values a RISC PC can reach with that page Regards