Our architects figured that the open source 3D stack would settle down around 60-70% of the fglrx performance on average, based on rough estimates of developer community size and priorities. The main assumptions were :
- relatively simple shader compiler (compared to the one in fglrx)
- primary focus on "making more apps run" (adding functionality) rather than "making them run faster"
- little or no optimization work for specific apps or workloads, essentially "one code path but a good one"
All indications are that the driver work is still on track to that kind of performance. It's probably running closer to 30% of fglrx performance right now but the developer focus is still almost entirely on functionality and stability not optimization.
There was some discussion about performance bottlenecks on #dri-devel over the weekend. It's probably fair to say that everyone agrees on the list of potential bottlenecks, but it's not clear which of those actually are the problem and not obvious how to determine the bottlenecks without actually coding alternative implementations for specific portions and seeing what the results are (ie big heap of work).
The immediate focus has been on understanding why the 3xx-5xx Gallium3D paths are slower than the corresponding "classic" HW driver paths. Airlied has done some work there and that brought the 300g performance closer to 300 (classic) but there are still some performance gaps which I believe are not fully understood yet.
Anyways, bottom line is that we are still expecting performance to end up around 2/3 of fglrx on average (ie maybe 2x what it is today), but the development focus right now is still on functionality and (IMO) rightly so.
- relatively simple shader compiler (compared to the one in fglrx)
- primary focus on "making more apps run" (adding functionality) rather than "making them run faster"
- little or no optimization work for specific apps or workloads, essentially "one code path but a good one"
All indications are that the driver work is still on track to that kind of performance. It's probably running closer to 30% of fglrx performance right now but the developer focus is still almost entirely on functionality and stability not optimization.
There was some discussion about performance bottlenecks on #dri-devel over the weekend. It's probably fair to say that everyone agrees on the list of potential bottlenecks, but it's not clear which of those actually are the problem and not obvious how to determine the bottlenecks without actually coding alternative implementations for specific portions and seeing what the results are (ie big heap of work).
The immediate focus has been on understanding why the 3xx-5xx Gallium3D paths are slower than the corresponding "classic" HW driver paths. Airlied has done some work there and that brought the 300g performance closer to 300 (classic) but there are still some performance gaps which I believe are not fully understood yet.
Anyways, bottom line is that we are still expecting performance to end up around 2/3 of fglrx on average (ie maybe 2x what it is today), but the development focus right now is still on functionality and (IMO) rightly so.
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