Radi preglednosti u odvojenom postu
PCI-e 2.0 16X = 8GB/s total bandwidth
PCI-e 2.0 8X = 4GB/s total bandwidth
ATI:
HD 3870 = 1125mhz (dual piped - 2.2 GB/s data rate) = 2.2 GB/s total data rate
HD 4650 = 500mhz (dual piped - 1 GB/s data rate) = 1 GB/s total data rate
HD 4670 = 1000mhz (single piped - 2 GB/s data rate) = 2 GB/s total data rate
HD 4770 = 800mhz (quad piped - 3.6 GB/s data rate) = 3.6 GB/s total data rate
HD 4830 = 900mhz = (dual piped - 1.9 GB/s data rate) = 1.9 GB/s total data rate
HD 4850 = 993mhz (dual piped - 1.9 GB/s data rate) = 1.9 GB/s total data rate
HD 4850 X2 = 993mhz (dual piped - 1.9 GB/s data rate)(times 2) = 3.8 GB/s total data rate
HD 4870 = 900mhz (quad piped - 3.6 GB/s data rate) = 3.6 GB/s total data rate
HD 4890 = 975mhz (quad piped - 3.9 GB/s data rate) = 3.9 GB/s total data rate
HD 4870 X2 = 900mhz (quad piped - 3.6 GB/s data rate)(times 2) = 7.2 GB/s total data rate
So as you can see, the 4870 X2 will be hurt in an 8X condition and why the 3870, 4650, 4670, 4770, 4830, 4850, 4870, 4890, and 4850 X2 will not be hurt in performance at all.
Nvidia:
8800 Ultra = 1080mhz (dual piped - 2.1 GB/s data rate) = 2.1 GB/s data rate
9600 GT = 900mhz (dual piped - 1.8 GB/s data rate) = 1.8 GB/s total data rate
9800 GTX = 1100mhz (dual piped - 2.2 GB/s data rate) = 2.2 GB/s total data rate
GTS 250 = 1100mhz (dual piped - 2.2 GB/s data rate) = 2.2 GB/s total data rate
GTX 260 216 = 999mhz (dual piped - 1.9 GB/s data rate) = 1.9 GB/s total data rate
GTX 275 = 1134mhz (dual piped - 2.2 GB/s data rate) = 2.2 GB/s total data rate
GTX 280 = 1053mhz (dual piped - 2.1 GB/s data rate) = 2.1 GB/s data rate
GTX 285 = 1242mhz (dual piped - 2.4 GB/s data rate) = 2.4 GB/s data rate
GTX 295 = 999mhz (dual piped - 1.9 GB/s data rate)(times 2) = 3.8 GB/s total data rate
GTX 285X2 = 1242mhz (dual piped - 2.4 GB/s data rate)(times 2) = 4.8 GB/s data rate
Ni sam ne znam sta da mislim. S jedne strane, po ovome se vidi da je tacno sta je rekao kokan, a s druge,ovde ima toliko lufta (recimo 2*4850,cf, samo kao primer, 2*1.9=3.6gb/s). To je dovoljno za 2x8 pcie, jer on ima propusnu moc od 2*4=8gb/s. Po tome, ne bi smela da postoji vise od 1% razlike u brzini izmedju 2*8 i 2*16 setup-a. A razlika je od prilike 5-7%, ako se dobro secam iz nekih testova. Mislim, vidim da to nije bas tako u realnosti kao matematici, ali bi onda 4x pcie(2gb/s bandwidth) slot bio dovoljan za 4850. Ima li neko misljenje o ovim nelogicnostima