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1<?xml version="1.0" encoding="UTF-8"?> 1<?xml version="1.0" encoding="UTF-8"?>
2<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/dri-howto.xml,v 1.43 2008/11/06 09:42:02 nightmorph Exp $ --> 2<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/dri-howto.xml,v 1.44 2009/11/30 20:19:35 nightmorph Exp $ -->
3<!DOCTYPE guide SYSTEM "/dtd/guide.dtd"> 3<!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
4 4
5<guide link="/doc/en/dri-howto.xml"> 5<guide>
6 6
7<title>Hardware 3D Acceleration Guide</title> 7<title>Hardware 3D Acceleration Guide</title>
8 8
9<author title="Author"> 9<author title="Author">
10 <mail link="dberkholz@gentoo.org">Donnie Berkholz</mail> 10 <mail link="dberkholz"/>
11</author> 11</author>
12<author title="Editor"> 12<author title="Editor">
13 <mail link="peesh@gentoo.org">Jorge Paulo</mail> 13 <mail link="peesh"/>
14</author> 14</author>
15<author title="Editor"> 15<author title="Editor">
16 <mail link="nightmorph@gentoo.org">Joshua Saddler</mail> 16 <mail link="nightmorph"/>
17</author> 17</author>
18 18
19<abstract> 19<abstract>
20This document is a guide to getting 3D acceleration working using the DRM with 20This document is a guide to getting 3D acceleration working using the DRM with
21Xorg in Gentoo Linux. 21Xorg in Gentoo Linux.
23 23
24<!-- The content of this document is licensed under the CC-BY-SA license --> 24<!-- The content of this document is licensed under the CC-BY-SA license -->
25<!-- See http://creativecommons.org/licenses/by-sa/2.5 --> 25<!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
26<license/> 26<license/>
27 27
28<version>1.11</version> 28<version>1.12</version>
29<date>2008-09-10</date> 29<date>2009-11-30</date>
30 30
31<chapter> 31<chapter>
32<title>Introduction</title> 32<title>Introduction</title>
33<section> 33<section>
34<title>What is hardware 3D acceleration and why do I want it?</title> 34<title>What is hardware 3D acceleration and why do I want it?</title>
289possible.)</comment> 289possible.)</comment>
290</pre> 290</pre>
291 291
292<note> 292<note>
293FPS may be limited by your screen's refresh rate, so keep this in mind if 293FPS may be limited by your screen's refresh rate, so keep this in mind if
294<c>glxgears</c> reports only about 70-100 FPS. <c>games-fps/ut2004-demo</c> is a 294<c>glxgears</c> reports only about 70-100 FPS. <c>games-fps/ut2004-demo</c> or
295better benchmarking tool, as it can give you real-world performance results. 295other 3D games are better benchmarking tools, as they give you real-world
296performance results.
296</note> 297</note>
297 298
298</body> 299</body>
299</section> 300</section>
300</chapter>
301
302<chapter>
303<title>Tweak your performance</title>
304<section> 301<section>
305<title>Get the most out of direct rendering</title> 302<title>Get the most out of direct rendering</title>
306<body> 303<body>
307 304
308<p> 305<p>
309A few options may increase performance by up to 30 percent (or more) over the 306If you want to set more features, for performance or other reasons, check out
310default. Set them in <path>/etc/X11/xorg.conf</path>. However, you will first
311need to check that your motherboard and video card support these options.
312</p>
313
314<p>
315First, let's see if your video card can support fast writes. We'll do this by
316closely inspecting the output from <c>lspci</c>. Specifically, we are looking
317at the "VGA compatible controller" information.
318</p>
319
320<pre caption="Video card check">
321# <i>lspci -vv</i>
32201:00.0 VGA compatible controller: ATI Technologies Inc Radeon Mobility M6 LY (prog-if 00 [VGA])
323. . .
324Capabilities: [58] AGP version 2.0
325 Status: RQ=48 Iso- ArqSz=0 Cal=0 SBA+ ITACoh- GART64- HTrans- 64bit- FW+ AGP3- Rate=x1,x2,x4
326</pre>
327
328<p>
329While quite a lot of information is produced, we are looking for <b>FW</b> in
330the "Status" subsection of the AGP "Capabilities" section. If <b>FW+</b> is
331present in the "Status" line, it means the card supports fast writes. We can
332now check if the motherboard supports fast writes.
333</p>
334
335<impo>
336If you do not see <b>FW+</b>, but instead see <b>FW-</b>, you cannot enable
337fast writes in <path>xorg.conf</path>. Your card does not support fast writes.
338</impo>
339
340<p>
341Now let's make sure the motherboard supports fast writes as well. This time,
342look at the "Host bridge" section of your <c>lspci</c> output.
343</p>
344
345<pre caption="Motherboard check">
346# <i>lspci -vv</i>
34700:00.0 Host bridge: Intel Corporation 82830 830 Chipset Host Bridge (rev 02)
348. . .
349Capabilities: [a0] AGP version 2.0
350 Status: RQ=32 Iso- ArqSz=0 Cal=0 SBA+ ITACoh- GART64- HTrans- 64bit- FW+ AGP3- Rate=x1,x2,x4
351</pre>
352
353<p>
354Again, examine the "Status" subsection of your AGP "Capabilities" section. Look
355for <b>FW</b>. If you see <b>FW+</b>, your motherboard supports fast writes.
356</p>
357
358<impo>
359Remember, both your video card information and your motherboard information
360must show the same <b>FW</b> capability. If either device shows <b>FW-</b> in
361"Status", you cannot enable fast writes in <path>xorg.conf</path>.
362</impo>
363
364<p>
365Assuming that all has gone well and both your motherboard and video card
366support fast writes, let's enable this option in
367<path>/etc/X11/xorg.conf</path> and get the best performance out of your
368hardware.
369</p>
370
371<pre caption="xorg.conf">
372Section "Device"
373 Option "AGPMode" "4"
374 <comment>(This increased FPS from 609 to 618.)</comment>
375 Option "AGPFastWrite" "True"
376 <comment>(This had no measurable effect, but it may increase instability of your computer.)</comment>
377 <comment>(You may also need to set it in your BIOS.)</comment>
378 Option "EnablePageFlip" "True"
379 <comment>(This improved FPS from 618 to 702. It also is "risky" but few people have reported problems.)</comment>
380 ...
381EndSection
382</pre>
383
384<warn>
385Enabling <c>AGPFastWrite</c> on a VIA chipset will very likely cause your
386machine to lock up. VIA chipsets do not play nicely with fast writes, so use
387this setting at your own risk.
388</warn>
389
390<note>
391Remember, if you want fast writes to work properly, you will have to first
392enable the appropriate option in your BIOS.
393</note>
394
395<p>
396If you want to set even more features, check out the <uri
397link="http://dri.freedesktop.org/wiki/FeatureMatrix">feature matrix</uri> on 307the <uri link="http://dri.freedesktop.org/wiki/FeatureMatrix">feature
398the DRI web site or the <uri 308matrix</uri> on the DRI web site or the <uri
399link="http://dri.sourceforge.net/doc/dri_driver_features.phtml">features 309link="http://dri.sourceforge.net/doc/dri_driver_features.phtml">features
400listing</uri> on Sourceforge. 310listing</uri> on Sourceforge.
401</p> 311</p>
402 312
403</body> 313</body>
467</p> 377</p>
468 378
469<pre caption="Enabling ForcePCIMode"> 379<pre caption="Enabling ForcePCIMode">
470Option "ForcePCIMode" "True" 380Option "ForcePCIMode" "True"
471</pre> 381</pre>
472
473</body>
474</section>
475</chapter>
476
477<chapter>
478<title>Acknowledgments</title>
479<section>
480<body>
481
482<ol>
483 <li>
484 Christopher Webber for suggesting a troubleshooting question about changing
485 or recompiling kernels
486 </li>
487 <li>
488 Steve, for suggesting consistency between the cases of dri and DRI in
489 XF86Config
490 </li>
491</ol>
492 382
493</body> 383</body>
494</section> 384</section>
495</chapter> 385</chapter>
496 386

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