On Wed, 22 Jun 2011 11:42:04 -0700 Eric Anholt <e...@anholt.net> wrote:
> On Tue, 21 Jun 2011 15:24:24 -0700, Jesse Barnes <jbar...@virtuousgeek.org> > wrote: > > The ring frequency scaling table tells the PCU to treat certain GPU > > frequencies as if they were a given CPU frequency for purposes of > > scaling the ring frequency. Normally the PCU will scale the ring > > frequency based on the CPU P-state, but with the table present, it will > > also take the GPU frequency into account. The scaling_factor used in > > this patch may not be ideal, but is enough to increase performance in > > nexuiz on a 1366x768 panel by about 20%. > > > > The main downside of keeping the ring frequency high while the CPU is > > at a low frequency (or asleep altogether) is increased power > > consumption. But then if you're keeping your GPU busy, you probably > > want the extra performance. > > The intent of the patch sounds good, but it doesn't seem to be doing > anything here (graphs below). If I run a "while true; do; done" loop to > keep a CPU busy during measurement, though, OA gets a 15.9% +/- 0.6% > win, and nexuiz around 20%. There are no complaints in dmesg. > > x /home/anholt/nexuiz-before > + /home/anholt/nexuiz-after > +-------------------------------------------------------------------------------+ > | x + + x x > +| > ||_|_______________________M____MA_____A_________________________|_________| > | > +-------------------------------------------------------------------------------+ > N Min Max Median Avg Stddev > x 3 59.217461 59.775295 59.479322 59.490693 0.27909057 > + 3 59.287311 59.893383 59.440451 59.540382 0.31515189 > No difference proven at 95.0% confidence > > x /home/anholt/oa-before > + /home/anholt/oa-after > +-------------------------------------------------------------------------------+ > |x x + + + x * + > x| > | |________________________|_________MA_______A______M__________|________| > | > +-------------------------------------------------------------------------------+ > N Min Max Median Avg Stddev > x 5 184.2 187.2 186.3 185.72 1.3809417 > + 5 185.4 187 185.7 186.04 0.71624018 > No difference proven at 95.0% confidence > > x /home/anholt/taiji-before > + /home/anholt/taiji-after > +-------------------------------------------------------------------------------+ > |x x + xx + x + ++ + > x| > | |____________________________A___|______________A______M_|_____| > | > +-------------------------------------------------------------------------------+ > N Min Max Median Avg Stddev > x 6 132.486 139.931 135.608 135.596 2.6966051 > + 6 134.974 138.832 138.111 137.41183 1.434609 > No difference proven at 95.0% confidence _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
