09-19-2014, 11:41 PM
We know the real-performance of the 750Ti, and since it is from the same GPU family, the 980 will scale linearly against it. Estimating the speed is simple arithmetic:
750Ti: 640 cores @ 1200 Mhz.
980: 2048 cores @ 1216 Mhz.
(2048 * 1216) / (640 * 1200) =~ 3.24
So the GTX 980 will be ~ 3.24x faster than the GTX 750Ti. Using the benchmarks from the 750Ti we can now determine what the speed will be like for each algorithm on the 980 (note: based on outdated benchmark figures!)
750Ti MD5 = 3022.7 MH/s * 3.24 = GTX 980 9793.5 MH/s
750Ti NTLM = 5185.9 MH/s * 3.24 = GTX 980 16802.3 MH/s
750Ti SHA1 = 1065.3 MH/s * 3.24 = GTX 980 3451.6 MH/s
These are not the latest numbers -- these are based on atom's benchmarks from May, which are surely outdated. But it illustrates how we can accurately estimate the speed for different GPUs (and CPUs) from the same family.
We can also do it by the instruction count as well, but I'm not sure what the instruction counts are at with LOP3.LUT. But just as an example, here's how we can e.g. estimate NTLM performance on the R9 290X without having one:
2816 cores * 1000000000 Hz / 130 instructions = 21.6 GH/s
Which is spot-on with the actual benchmark:
Speed.GPU.#2.: 21663.7 MH/s
750Ti: 640 cores @ 1200 Mhz.
980: 2048 cores @ 1216 Mhz.
(2048 * 1216) / (640 * 1200) =~ 3.24
So the GTX 980 will be ~ 3.24x faster than the GTX 750Ti. Using the benchmarks from the 750Ti we can now determine what the speed will be like for each algorithm on the 980 (note: based on outdated benchmark figures!)
750Ti MD5 = 3022.7 MH/s * 3.24 = GTX 980 9793.5 MH/s
750Ti NTLM = 5185.9 MH/s * 3.24 = GTX 980 16802.3 MH/s
750Ti SHA1 = 1065.3 MH/s * 3.24 = GTX 980 3451.6 MH/s
These are not the latest numbers -- these are based on atom's benchmarks from May, which are surely outdated. But it illustrates how we can accurately estimate the speed for different GPUs (and CPUs) from the same family.
We can also do it by the instruction count as well, but I'm not sure what the instruction counts are at with LOP3.LUT. But just as an example, here's how we can e.g. estimate NTLM performance on the R9 290X without having one:
2816 cores * 1000000000 Hz / 130 instructions = 21.6 GH/s
Which is spot-on with the actual benchmark:
Speed.GPU.#2.: 21663.7 MH/s