Also see benchmark results at http://www.serkey.com/ubuntu-gtkperf...in-bfkcp5.html where gtkperf on kwin takes three times longer than KDE with no effects.
The widgets theme does indeed have a very significant impact on performance. I ran the tests where KDE performed particularly poorly on my machine. I run KDE 4.11, VSync in KWin was switched off. Qt rendering engine was set to Raster (I forced Raster during tests in TWM too). My machine is a sorry-ass 4 year old laptop with T9550/nVidia 9800GTS (proprietary drivers v. 325.15).
QtPerf QCheckBox 5000x (sec)
In KDE with KWin:
- Qxygen: 1.634 ± 0.087
- QtCurve: 1.403 ± 0.055
- CDE: 1.363 ± 0.377
In plain TWM:
- 1.334 ± 0.206
GtkPerf GtkCheckButton 5000x (sec)
In KDE with KWin
- Oxygen-gtk: 6.84 ± 0.61
- QtCurve: 2.47 ± 0.07
- Raleigh: 1.61 ± 0.07
In plain TWM:
- 1.54 ± 0.03
QGears2 COMPO (FPS)
- Qxygen: 273.224 ± 3.358
- CDE: 558.729 ± 15.183
The performance more than doubled. If you multiply the result Michael got, you'll see that KDE is on par with other DE's except Unity.
I believe this shows that there is nothing wrong with KDE's/KWin's rendering performance. It's also worth noting that KWin in KDE 4.11 introduced improved VSync which could have impacted the performance, especially if it wasn't set correctly. Folks with Intel GPU's could give this a try...
Where these results with or without XMir?
This is clearly an Oxygen-gtk issue. I ran a few benchmarks where KDE 4.11 performed particularly poorly myself to verify that. I used my 4 year old laptop with T9550/nV 9800 GTS(props v. 325.15). KWin compositing was on, VSync set to "None", rendering engine "Raster", OpenGL 3.1.
QtPerf, QCheckBox test 5000x (sec)
Oxygen: 1,634 ± 0,087
QtCurve: 1,403 ± 0,055
CDE theme: 1,363 ± 0,377
Plain TWM (raster engine enforced): 1,334 ± 0,206
GtkPerf, GtkCheckButton test 5000x (sec)
Oxygen-gtk: 6,84 ± 0,61
QtCurve: 2,47 ± 0,07
Raleigh: 1,61 ± 0,07
Plain TWM: 1,54 ± 0,03
QGears COMPO (fps)
Oxygen: 273,224 ± 3,358
CDE theme: 558,729 ± 15,183
KDE 4.11 is not slower than any other DE, it's just the Oxygen theme that is quite CPU heavy. Users with weaker machines will probably want to use QtCurve instead. It's also worth noting that KWin in KDE 4.11 has improved VSync which could probably slow 2D rendering down as well if it's set incorrectly. I can't test this because VSync doesn't appear to be an issue on my GPU.
The main problem with windows 8 is it has two entirely different interfaces and sets of application 'at war with each other', and it makes for a very inconsistant and annoying expereicne. Metro is basically its own DE with its own applications, and in windows 8 it is shoehorned as being the "start menu", and the integration with the classic desktop is half-assed.
Unity and gnome-shell are still unified interfaces that don't have this problem. If the unity dash or gnome-shell overlay had its own apps that could only run inside the dash, and the dash was fullscreen and its own environment then you could compare it to windows 8
In the end it always comes back to talk about Unity, this means that like it or not is crucial. I think Unity is one of the best Shell, I could not help it, dash and hud are fundamental for me. I am happy the tests and I hope that these Unity best ever.
I also wish people would stop saying unity and gnome-shell are "touch optimized" and not desktop optimized. Unity 7 is totally desktop optimized and not very touch friendly at all. have you ever tried to use unity on a touchscreen? Unity is a hell of a lot more keyboard and mouse friendly than touch friendly. The upcoming unity 8 will be far more touch optimized though, but the plan is for unity 8 to have a 'desktop mode' that works like unity 7 afiak so it should work as well on the desktop as unity 7 does, and as I mentioned I certainly wouldn't call unity 7 "touch optimized". Gnome-shell isn't very good on touchscreens yet either (although it is something they are working on), and like unity gnome-shell is very keyboard friendly and right now its a lot more 'desktop friendly' than 'touch friendly'. I use gnome-shell on my laptop and I like it much better than windows 8. I ran windows 8 for a few months on my gaming desktop but ended up going back to windows 7.
Last edited by bwat47; 08-31-2013 at 06:09 PM.