43 lines
2.3 KiB
Plaintext
43 lines
2.3 KiB
Plaintext
Q: Why is EVAS faster with software acceleration than than when I run it
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with hardware acceleration switched on?
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A: When run with hardware acceleration EVAS uses the GL libraries on your
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system; this means that if you have Mesa installed then EVAS will use
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the Mesa GL liberties. Mesa however only provides software acceleration
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and therefore will run slow compared to EVASs in-built software mode. If
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you have a video card that supports hardware acceleration then you should
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attempt to get the manufacturers own GL drivers for your computer and
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install them making sure that none of the Mesa libraries are left behind
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and that where needed sym-links are made to the real drivers.
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Q: Why is 'program x' which uses EVAS so slow?
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A: See last question. The chance is that the program is trying to use
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hardware acceleration by default and that you have Mesa GL libraries
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installed on your system. If you don't have acceleration on your video
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card then you should search for a way to switch to software acceleration
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in the program.
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Q: Is there a packaged version of SGI's GLU Implementation for my computer
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anywhere?
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A: At present SGI's GLU Implementation is available only in the form of a
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Redhat package from http://www.mesa3d.org/downloads/sgi.html. You should
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download this package and convert it to whatever distribution you are
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on using "alien".
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Q: Why is my CPU usage at 100% when I use a program running EVAS?
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A: When used in software mode, EVAS will use a lot of CPU. In hardware
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mode however it depends on your OpenGL drivers. What a lot of drivers
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do is limit buffer buffer swaps to vertical blanking gaps only. This
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means that the buffers wont be swapped until the vertical blanking gap
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is reached, however since there is no method of using interrupts under
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Linux/X the GL drivers have to poll in a tight loop waiting for the gap.
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Also if the GL libs are accessing the GFX hardware directory then if the
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hardware is busy then the app will sit and poll registers until the
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hardware is ready. It's basically down to your OpenGL drivers. It's worth
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noting as well that your CPU will be high whenever you run evas_test as
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it is pushing your system to try and achieve the highest frame rate it
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can, a situation that most software using EVAS will never be in.
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