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Re: Surface RT - horrible performance for native games

PostPosted: Mon Dec 03, 2012 5:39 am
by thehen

Re: Surface RT - horrible performance for native games

PostPosted: Mon Dec 03, 2012 3:07 pm
by Ashley
It sounds like performance on Windows 8 ARM devices is worse than the hardware suggests ought to be possible.

It may be that IE10's JIT compiler for ARM is just not very good. IE10 is the first version of IE that runs on ARM (IIRC), whereas both Chrome and Safari on Android and iOS respectively have been around for years on ARM devices and probably have had much more optimisation work done.

Maybe IE10 doesn't even compile javascript on ARM! I'm not sure where to find out more about that... might be worth asking MS.

Re: Surface RT - horrible performance for native games

PostPosted: Mon Dec 03, 2012 9:14 pm
by EyeHawk
@Ashley - yeah it's definitely worth looking into. I'll do a bit of digging with some of the local MS guys.

Re: Surface RT - horrible performance for native games

PostPosted: Tue Apr 30, 2013 12:18 pm
by thehen
I've just found that upscaling the canvas from 75% of the device resolution results in very large performance gains.

Can anyone else confirm that adding @-ms-viewport { width:75% } to the exported index.html has the same effect in their games? If so I'll package it up as a plugin.thehen2013-04-30 12:19:06

Re: Surface RT - horrible performance for native games

PostPosted: Tue Apr 30, 2013 2:25 pm
by Ashley
@thehen - what resolution is the game running at?

We've seen issues on the iPad 3 where a 2048 size texture is very slow, but a 2046 size texture is very fast. My theory is that it internally adds a one pixel border to whatever you ask for, pushing 2048 over the maximum supported texture size. Then the GPU is actually rendering to two 2048x2048 size image tiles, which halves performance.

If you're running at 1366x768, it's possible the GPU is working with a 2048x2048 texture, or two 1024x1024 size textures. 75% of that, rounded down, is 1024 - so it can use a smaller render texture, or just one where it would have used two. I'm not sure if this qualifies as a bug, but you might want to make someone at MS aware of it. To test the theory, try 74% (which is just over 1024), and it should be slow again.

Re: Surface RT - horrible performance for native games

PostPosted: Tue Apr 30, 2013 3:37 pm
by thehen
@Ashley - apologies I should have tested this more comprehensively before posting. Differing frame-rate was just down to environmental differences, upscaling has negligible impact on the Surface.

Re: Surface RT - horrible performance for native games

PostPosted: Tue Apr 30, 2013 7:53 pm
by viperx77
All over the world... just not in my town. :-)

Re: Surface RT - horrible performance for native games

PostPosted: Wed May 01, 2013 1:35 am
by BluePhaze
If anyone wants a test on an ARM based surface and can't get a hold of one, let me know and I can test your app on mine. I am wondering if the performance and firmware updates over the past couple months have changed much for perf on Surface RT.

Re: Surface RT - horrible performance for native games

PostPosted: Fri May 10, 2013 3:43 am
by crushingdower
Hmm, I just began stumbling into this... I have a Surface Pro, a Surface RT and an iPad3... I was surprised how poorly my game performed on the RT! So, I'm guessing this is just the way the Surface RT is?