8 ms·
There's 2 to 3 feet between me and my screen, my cpu has 2 cores, and modern CPUs can perform many simple arithmetic operations per clock cycle, per core. Not t
by yan 16y ago
There's 2 to 3 feet between me and my screen, my cpu has 2 cores, and modern CPUs can perform many simple arithmetic operations per clock cycle, per core. Not to mention what's happening in my GPU.
- pjscott 16y agoLet's take a concrete example. A Core-i7 980X Extreme Edition, the latest and greatest from Intel, can execute a maximum of four instructions in a clock cycle. (The numbers on actual code are probably a little over 1 instruction per cycle, which is really pretty good.) It runs at 3.33 GHz and has 6 cores. That's a theoretical maximum of about 43.336 = 79 instructions per nanosecond, on all cores combined. Assuming I didn't make some dumb arithmetic mistake. Of course, in real code you'll be lucky to get anywhere near that.
- acqq 16y agoRegarding double precision calculations (I can't compare random instructions) at the time OP mentions the PC FPU made something of the order of KFLOPS. Even assuming 100 KFLOPS (it was less), one current graphical card can be up to 5 million times faster than the PC of that time in some scientific calculations, that is, the gamer of today has under his desk the computing power of 5 million first PC computers. i7 can do 2 double precision adds per clock per core, that would give 36 GFLOPS on 6 cores (assuming 3 GHz clock), and at the same time ATI Radeon 5870 GPU can do 500 GFLOPS in double precision, that's 500 floating point calculations in one nanosecond. To cross the 0.5 meter distance the light takes around 1.6 ns, which means that during that time the CPU is able to do almost 60 FPU additions and the GPU around 800 FPU additions. Impressive.