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      <base href="https://bugs.freedesktop.org/">
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - Kabylake has poor performance with single display configurations"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=102199">102199</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Kabylake has poor performance with single display configurations
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>DRI
          </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>DRM/Intel
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>intel-gfx-bugs@lists.freedesktop.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>lyude@redhat.com
          </td>
        </tr>

        <tr>
          <th>QA Contact</th>
          <td>intel-gfx-bugs@lists.freedesktop.org
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>intel-gfx-bugs@lists.freedesktop.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Created <span class=""><a href="attachment.cgi?id=133474" name="attach_133474" title="dmidecode output">attachment 133474</a> <a href="attachment.cgi?id=133474&action=edit" title="dmidecode output">[details]</a></span>
dmidecode output

So, I've been trying to figure out why gnome-shell has been running slowly on
my laptop and unfortunately me and one of my coworkers have traced this down to
a rather interesting power issue: i915 doesn't upclock Kabylake GPUs quickly
enough to run gnome shell's animations smoothly, but only when running with a
single display. For instance, when continuously entering and exiting the
activities overlay according to /sys/kernel/debug/dri/0/i915_frequency_info,
the GPU almost never goes above 500MHz when running animations on a single
screen. The shell animations run at about 20FPS, and if I force the GPU's
frequency up using i915_min_freq animations begin running at 60 FPS again.
When running with two or more displays however, this problem never seems to
happen. The GPU upclocks as expected when shell animations start, and
everything runs fluidly at ~55-60 FPS.

The machine in question is a razer blade stealth running Fedora 26. The display
being used in the single monitor configuration is the built-in eDP 4K display.
I've tried the latest 4.13 rc4 kernel, and unfortunately the performance isn't
much better.

I've attached my dmidecode, and will reboot and attach a dmesg with
drm.debug=0x6 in just a moment. let me know if you need any more information.</pre>
        </div>
      </p>


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