http://www.phoronix.com/scan.php?page=article&item=ati_r500_3d&num=1

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SZERVÁC Attila

If you are drawing and *not* hitting exactly on the pixel grid, the resulting edges will need to be blended. If the destination surface does not support accelerated operations with alpha, it means that the destination image needs to be fetched from the video memory (SLOW), composited in software and then pushed back.

This holds true for rectangular integer-positioned fills too, for the reason described in http://cairographics.org/FAQ/#sharp_lines

If you want somewhat consistent performance regardless of bad drivers, do *all* your compositing in software (ie. construct the whole graph in cairo image surfaces) and just blit the result to the server side surface. This sucks for network clients though as the clientserver traffic is increased.

Unfortunately the “somewhat consistent” part implies that it can only be as fast as your blit from the client side, and doesn’t get faster even if your graphics hardware could do all the work instead of your CPU.

So in other words: IMO there isn’t a full satisfactory solution for this that doesn’t involve fixing/providing good drivers to graphics hardware. Fortunately that situation (slowly) changing for the better.

http://gwallgofi.com/sysmon.jpg

It’s on a Intel Core 2 Duo 2.2GHz system with NVidia 8600 graphics and 2GB of RAM…so system grunt isn’t an issue here(!)

I simply just don’t touch the graphics area when using System Monitor (although I actually use htop mostly)

If you use a tool to measure something, would it be ok if it disturbed its subject this much? It’s basically measuring itself..

Something really has to be done and the pretty graphs have to taste the axe because more than 1-3 % absolute error is not ok by me..