I have tested the ppa from +Stefan Glasenhardt (glasen) and I have noticed that the fix doesn't solve the problem entirely.

unity:
  Installiert: 5.12.1~glasen~ppa1
  Kandidat:    5.12.1~glasen~ppa1
  Versionstabelle:
 *** 5.12.1~glasen~ppa1 0
        500 http://ppa.launchpad.net/glasen/unity-performance-fix/ubuntu/ precise/main amd64 Packages
        100 /var/lib/dpkg/status
     5.12-0ubuntu1 0
        500 http://archive.ubuntu.com/ubuntu/ precise-updates/main amd64 Packages
     5.10.0-0ubuntu6 0
        500 http://archive.ubuntu.com/ubuntu/ precise/main amd64 Packages
compiz:
  Installiert: 1:0.9.7.8-0ubuntu1
  Kandidat:    1:0.9.7.8-0ubuntu1
  Versionstabelle:
 *** 1:0.9.7.8-0ubuntu1 0
        500 http://archive.ubuntu.com/ubuntu/ precise-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     1:0.9.7.6-0ubuntu1 0
        500 http://archive.ubuntu.com/ubuntu/ precise/main amd64 Packages
xserver-xorg-video-intel:
  Installiert: 2:2.19.0-0ubuntu1~xup1
  Kandidat:    2:2.19.0-0ubuntu1~xup1
  Versionstabelle:
 *** 2:2.19.0-0ubuntu1~xup1 0
        500 http://ppa.launchpad.net/ubuntu-x-swat/x-updates/ubuntu/ precise/main amd64 Packages
        100 /var/lib/dpkg/status
     2:2.17.0-1ubuntu4 0
        500 http://archive.ubuntu.com/ubuntu/ precise/main amd64 Packages

This are my results from ioquake 3 in window mode with a resolution of 1280x720.
Desktop resolution is 1920x1080.

1260 frames 26.3 seconds 48.0 fps 4.0/20.9/40.0/5.8 ms unity fix 50 Hz
1260 frames 25.3 seconds 49.8 fps 3.0/20.1/42.0/7.2 ms unity fix 60 Hz
1260 frames 25.2 seconds 50.0 fps 9.0/20.0/38.0/3.5 ms gnome classic compiz 50 Hz
1260 frames 21.5 seconds 58.7 fps 6.0/17.0/34.0/3.8 ms gnome classic compiz 60 Hz

                      IOquake3 1280x720 60Hz in Window-mode

  65 +---------------------------------------------------------------------+
  64 +--------------------------------------------Frames Per Second-******-+
  63 +---------------------------------------------------------------------+
  62 +---------------------------------------------------------------------+
  60 +---------------------------------------------------------------------+
  59 +---------------------------------------------------------------------+
  58 +--------------------------------------------------------**********---+
  57 +--------------------------------------------------------*--------*---+
  56 +--------------------------------------------------------*--------*---+
  55 +--------------------------------------------------------*--------*---+
  54 +--------------------------------------------------------*--------*---+
  53 +--------------------------------------------------------*--------*---+
  52 +--------------------------------------------------------*--------*---+
  50 +--------------------------------------**********--------*--------*---+
  49 +---------------------**********-------*--------*--------*--------*---+
  48 +---**********--------*--------*-------*--------*--------*--------*---+
  47 +---*--------*--------*--------*-------*--------*--------*--------*---+
  46 +---*--------*--------*--------*-------*--------*--------*--------*---+
  45 +---**********--------**********-------**********--------**********---+
       Unity fix 50Hz   Unity fix 60Hz     Classic 50Hz     Classic 60Hz