<html>
<head>
<base href="https://bugs.freedesktop.org/">
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - 4-27% performance drop in Vulkan benchmarks"
href="https://bugs.freedesktop.org/show_bug.cgi?id=109216">109216</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>4-27% performance drop in Vulkan benchmarks
</td>
</tr>
<tr>
<th>Product</th>
<td>Mesa
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>Other
</td>
</tr>
<tr>
<th>OS</th>
<td>All
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>medium
</td>
</tr>
<tr>
<th>Component</th>
<td>Drivers/Vulkan/intel
</td>
</tr>
<tr>
<th>Assignee</th>
<td>intel-3d-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>eero.t.tamminen@intel.com
</td>
</tr>
<tr>
<th>QA Contact</th>
<td>intel-3d-bugs@lists.freedesktop.org
</td>
</tr>
<tr>
<th>CC</th>
<td>jason@jlekstrand.net
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=142959" name="attach_142959" title="Avoid Vsync / Mailbox mode in fullscreen">attachment 142959</a> <a href="attachment.cgi?id=142959&action=edit" title="Avoid Vsync / Mailbox mode in fullscreen">[details]</a></span> <a href='page.cgi?id=splinter.html&bug=109216&attachment=142959'>[review]</a>
Avoid Vsync / Mailbox mode in fullscreen
Setup:
* Ubuntu 18.04 / Unity desktop
* Mesa git version
* X server & drm-tip kernel built from git within last couple of months
* Modifiers enabled in X server configuration ("dmabuf_capable")
Vulkan performance noticeably dropped on all Vulkan supporting platforms (at
least from HSW to CFL) between following Mesa commits:
2018-12-17 17:52:23 00e2cbc049 v3d: Fix the argument type for vir_BRANCH()
2018-12-18 18:47:54 29e4b949b4 Revert "nir/lower_indirect: Bail early if modes
== 0"
E.g. on KBL 7500U (GT2), performance drops were following:
- 27% Deferred Multisampling (*)
- 9% Compute NBody (*)
- 6% Compute Raytracing (*)
- 4% GfxBench Vulkan Aztec Ruins normal
(*) Sacha Willems' Vulkan demo, run at FullHD fullscreen, with Vsync disabled
i.e. NOT using mailbox mode as that seems to get Vsynched although Vsync is
supposed to be disabled (see attachment). For example:
./deferredmultisampling --fullscreen --benchmark --benchwarmup 3
--benchruntime 20
E.g. in Deferred Multisampling case; GPU, CPU and memory power usage drops
clearly with the performance, so I assume it's become more synchronous.
Performance didn't drop in following of the Vulkan demos:
* Triangle (so it's unlikely to be related to modifiers)
* Multithreading
* Indirect Draw
(Don't have data for the rest of the Vulkan demos.)</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are the QA Contact for the bug.</li>
<li>You are the assignee for the bug.</li>
</ul>
</body>
</html>