1.  Does anyone know how fast the Zune is, and if it has an FPU (floating point processor).  I want to know if I'll get any speedup by doing everything in fixed point math.

2.  Does anyone know how to properly draw per pixel graphics.  Right now I'm creating Texture2D and an Array[Color] and then setting the colors in the array and using Texture2D.SetData<Color>(Array) to set the texture pixel data, and then I draw the texture full screen.

3.  Is there any way to write an xml file to the zune from the game, and if so, how to read that xml file back?  I'm trying to do some profiling.

ColossalRobot:

1.  Does anyone know how fast the Zune is, and if it has an FPU (floating point processor).  I want to know if I'll get any speedup by doing everything in fixed point math.

That's a good question to which I have no answer. I just didn't want to ignore it :).

2.  Does anyone know how to properly draw per pixel graphics.  Right now I'm creating Texture2D and an Array[Color] and then setting the colors in the array and using Texture2D.SetData<Color>(Array) to set the texture pixel data, and then I draw the texture full screen.

That's pretty much how you would do it. You can use the overloaded SetData to set just certain areas of pixels which will yield a speed boost if you aren't changing some pixels.

3.  Is there any way to write an xml file to the zune from the game, and if so, how to read that xml file back?  I'm trying to do some profiling.

Using System.Xml just like you would on Windows. Give it a Google to see how it works. The only caveat is that you have to use the storage APIs to get a proper StorageContainer to save to when working on the Zune.

I believe the Zune has a ARM cpu which maxes out at 533mhz.

 

http://en.wikipedia.org/wiki/Zune_Media_Player

Thanks for the info!  In regards to #3 do you know how I can get a StorageDevice object while running on the Zune?  On 360 it seems like you have to use the guide, but that doesn't seem like it would work on the Zune.

Yep! Guide.BeginBlahblah works on the Zune!

The Zune does have an FPU, we also enabled FPU JIT support in the .NETCF for Zune.  

Do you know what kind of performance can be expected from the FPU?  I am trying to write a voxel based terrain engine, and right now it's only running at 2fps with everything in floating point.  Do you think I'll get a speed-up if I convert it to 12-20 fixed point?

So I used the StorageDevice and System.Xml stuff to generate and save an xml file on my Zune... but now I can't figure out how to get it back to my PC.  Are these files magically transferred somewhere, and if not how can I retrieve them?

There is no way to transfer files back to the PC during regular Zune sync or Visual Studio connection.

The only workaround is to send the information through the Debug channel using Debug.Write and then cut & paste from the debug window in VS

I'm going to risk the wrath of EULA breaking, because I feel it's information that is quite useful to people, plus, I don't think it actually breaks the EULA anyway since it's benchmarking hardware and not (particularly) the .Net Framework itself.

In some Vector Addition/Multiplication/Division tests someone ran on #xna last night for me, it performed about 40 times slower than my desktop PC. However, my CPU is a Q6600 running at 3.5Ghz (rather than 2.4) so halving that would probably be fair for a typical desktop CPU, 20 times slower. Bear in mind that the 360 runs about 7-8 times slower, I think the Zune is holding its own pretty well against the 360, then again, we know the JIT on the 360 is a long way from perfect.

At 20 times slower, by my artificial measurements, it should still be capable of some pretty good stuff, we'll just have to wait for Shawn to run an "Optimising Code for Zune" presentation at GDC/Gamefest/etc. :)