On Mon, 2010-10-25 at 13:14 -0700, Eric Anholt wrote: I'm taking a bet on memory bandwidth being the constraint for fill limited applications. glxgears manages 59fps at full screen (minus title bar), which is 1680x1024, giving a pixel rate of approx 100Mpix/second
(Ignoring over-fill) Assuming 2 bytes per pixel (ignoring possibility of depth / stencil writes), that is 200M bytes / second. Now I don't know what the likely memory bandwidth of the GMCH is, but I bet with scan out and other activity going on, we'll be pushing it quite hard to sustain that framerate. I'm targeting a desired ~15-20fps at nearly full-screen for my circuit board design app, so I will need to be careful with my code! This said, some top-range current cards from other manufacturers are claiming fill-rates in 10s of BILLIONS per second, and memory bandwidth of 10s up to ~100 GB/sec! (Although it comes with more than half the ram I have in this laptop, and probably costs about 1/2 - 3/4 what the laptop did). -- Peter Clifton Electrical Engineering Division, Engineering Department, University of Cambridge, 9, JJ Thomson Avenue, Cambridge CB3 0FA Tel: +44 (0)7729 980173 - (No signal in the lab!) Tel: +44 (0)1223 748328 - (Shared lab phone, ask for me) _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
