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#ActualSimonForsman

Posted 11 January 2013 - 07:34 PM

<blockquote class="ipsBlockquote" data-author="Servant of the Lord" data-cid="5020467"><p>It may be faster in the exact specific way that Valve's (aging) engine architecture could benefit from, or those specific video cards they were testing from, but that doesn't mean OpenGL is faster than DirectX in general. Part of the speed gain they even hinted was from Linux vs Windows and not OpenGL vs DirectX specifically, and the difference between 3.30 and 3.17 milliseconds per frame is only 0.13 milliseconds.<br /> <br />Being that they both are different ways of accessing the same videocard, and neither does alot of heavy processing themselves, they should both be fairly close in speed.</p></blockquote><br />
The big part of the DX vs OpenGL difference on Windows for Valve most likely boils down to it being D3D9(Which has a higher drawcall overhead than OpenGL and D3D10+ and that can easily add up to a hundred or so microseconds per frame(This seems to be valves conclusion aswell),
It is pretty much irrelevant now since D3D9 is on its last legs anyway.

(in reply to some other post, not quoting since the forum screws up my posts anyway and its a pain to fix every time)
I don't quite see where the info that microsoft purposely slowed down OpenGL for Vista came from, i was under the impression that the OpenGL->D3D wrapper they added in Vista only were supposed to replace the insanely slow OpenGL software renderer they had in older Windows versions. (So if anything they made OpenGL without proper drivers faster)

#2SimonForsman

Posted 11 January 2013 - 07:34 PM

<blockquote class="ipsBlockquote" data-author="Servant of the Lord" data-cid="5020467"><p>It may be faster in the exact specific way that Valve's (aging) engine architecture could benefit from, or those specific video cards they were testing from, but that doesn't mean OpenGL is faster than DirectX in general. Part of the speed gain they even hinted was from Linux vs Windows and not OpenGL vs DirectX specifically, and the difference between 3.30 and 3.17 milliseconds per frame is only 0.13 milliseconds.<br /> <br />Being that they both are different ways of accessing the same videocard, and neither does alot of heavy processing themselves, they should both be fairly close in speed.</p></blockquote><br />
The big part of the DX vs OpenGL difference on Windows for Valve most likely boils down to it being D3D9(Which has a higher drawcall overhead than OpenGL and D3D10+ and that can easily add up to a hundred or so microseconds per frame(This seems to be valves conclusion aswell),
It is pretty much irrelevant now since D3D9 is on its last legs anyway.

(in reply to some other post, not quoting since the forum screws up my posts anyway and its a pain to fix every time)
I don't quite see where the info that microsoft purposely slowed down OpenGL for Vista came from, i was under the impression that the OpenGL->D3D wrapper they added in Vista only were supposed to replace the insanely slow OpenGL software renderer they had in older Windows versions. (So if anything they made OpenGL without proper drivers faster)

#1SimonForsman

Posted 11 January 2013 - 07:31 PM

<blockquote class="ipsBlockquote" data-author="Servant of the Lord" data-cid="5020467"><p>It may be faster in the exact specific way that Valve's (aging) engine architecture could benefit from, or those specific video cards they were testing from, but that doesn't mean OpenGL is faster than DirectX in general. Part of the speed gain they even hinted was from Linux vs Windows and not OpenGL vs DirectX specifically, and the difference between 3.30 and&nbsp;3.17&nbsp;milliseconds&nbsp;per frame is only 0.13&nbsp;milliseconds.<br />&nbsp;<br />Being that they both are different ways of accessing the same videocard, and neither does alot of heavy processing themselves, they should both be fairly close in speed.</p></blockquote><br />The big part of the DX vs OpenGL difference on Windows for Valve most likely boils down to it being D3D9(Which has a higher drawcall overhead than OpenGL and D3D10+ and that can easily add up to a hundred or so microseconds per frame(This seems to be valves conclusion aswell), It is pretty much irrelevant now since D3D9 is on its last legs anyway.<br /><br />I don't quite see where the info that microsoft purposely slowed down OpenGL for Vista came from, i was under the impression that the OpenGL-&gt;D3D wrapper they added in Vista only were supposed to replace the insanely slow OpenGL software renderer they had in older Windows versions. (So if anything they made OpenGL without proper drivers faster)

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