Thank you for the fast replies!
With "can't find any message, if Firefox is using the hardware or not" I meant some feedback from fierfox, that it found the hardware and will be using it. That's where Ashleys tip was very helpful!
Firefox 4+ uses hardware acceleration, but only if your drivers are up to date. Go Firefox menu -> Help -> Troubleshooting information, and under "Graphics", check "Direct2D enabled" is "true".
I did so and following is the text file created from 'Troubleshooting'. It's a german version, but the important part is under 'Grafik' (= Graphics). There is no item where it says, "Direct2D enabled". The very last entry says "GPU-accelerated windows" and lists 1 with Direct3D 9, but that's all I could find about acceleration at all:
[EDIT] I also used 'about:config' to find anything about Direct2D. I found this entry: gfx.direct2d.disabled;false [/EDIT]
Allgemeine Informationen
Name
Firefox
Version
6.0.2
User-Agent
Mozilla/5.0 (Windows NT 5.1; rv:6.0.2) Gecko/20100101 Firefox/6.0.2
Profilordner
Beinhaltenden Ordner anzeigen
Aktivierte Plugins
about:plugins
Build-Konfiguration
about:buildconfig
Erweiterungen
Name
Version
Aktiviert
ID
Adblock Plus
1.3.9
true
{d10d0bf8-f5b5-c8b4-a8b2-2b9879e08c5d}
Download Statusbar
0.9.8
true
{D4DD63FA-01E4-46a7-B6B1-EDAB7D6AD389}
DownloadHelper
4.9.5
true
{b9db16a4-6edc-47ec-a1f4-b86292ed211d}
Java Quick Starter
1.0
true
jqseis@sun.com
Microsoft .NET Framework Assistant
0.0.0
true
{20a82645-c095-46ed-80e3-08825760534b}
Java Console
6.0.24
false
{CAFEEFAC-0016-0000-0024-ABCDEFFEDCBA}
Java Console
6.0.26
false
{CAFEEFAC-0016-0000-0026-ABCDEFFEDCBA}
Mehr Leistung und Videoformate f?r dein HTML5 <video>
2.1.2.126
false
{23fcfd51-4958-4f00-80a3-ae97e717ed8b}
Modifizierte Einstellungen
Name
Wert
accessibility.typeaheadfind.flashBar
0
browser.places.importBookmarksHTML
false
browser.places.importDefaults
false
browser.places.leftPaneFolderId
-1
browser.places.migratePostDataAnnotations
false
browser.places.smartBookmarksVersion
2
browser.places.updateRecentTagsUri
false
browser.startup.homepage
about:home
browser.startup.homepage_override.buildID
20110902133214
browser.startup.homepage_override.mstone
rv:6.0.2
extensions.lastAppVersion
6.0.2
network.cookie.prefsMigrated
true
places.database.lastMaintenance
1316176172
places.history.expiration.transient_current_max_pages
64400
privacy.donottrackheader.enabled
true
privacy.sanitize.migrateFx3Prefs
true
security.warn_viewing_mixed
false
Grafik
Karten-Beschreibung
NVIDIA GeForce 9400 GT
Vendor-ID
10de
Ger?te-ID
0641
Karten-Ram
Unknown
Karten-Treiber
nv4_disp
Treiber-Version
6.14.12.8026
Treiber-Datum
8-3-2011
WebGL-Renderer
Google Inc. -- ANGLE -- OpenGL ES 2.0 (ANGLE 0.0.0.686)
GPU-beschleunigte Fenster
1/1 Direct3D 9