I’m glad it worked for you.
The sound of your PC is normal, because if you disable the GPU, then the CPU has to do all the work.
I just upgraded to Vegas 13 recently, and came from Vegas 10, which didn’t have GPU support, so I have an idea what you hear. Don’t worry about it.
I’m still evaluating V13 and it’s GPU support and my experiences are a mixture of good and bad things.
Good is that with GPU (Radeon 6970) things work a whole lot faster, for example I can 25fps preview/full a text over a blurred image and on another track there’s another image which needs chroma key and than drop shadow… all this with 20% CPU load, and my CPU is not a top notch (i5 3570).
In Vegas 10 I had to do a selective prerender to be able to preview this timeline, because the CPU alone could do only 1/2 fps.
So the GPU support is great, when it works. But the sad thing is that t’s heap of bugs, and often behaves unpredictable, or reproduceable wrong.
So when something weird is happening, the first thing anyone will suggest to disable GPU support. I know, that’s disappointing. (Well, for me it is definitely)
My only hope is that Magix will fix these issues in V14.
Kind regards