I'm honestly thinking, that with the 2MB cache on the processor that this thing will give you even more feeling that your current desktop processor wise. As for the Vid card, is that just a standard 6800 (Non GT\Ultra) Overclocked? If so, this info may help.
Video Card comparison on Hothardware
From the max bandwidth let's just assume that the standard 6800's and the standard X800 are pretty close in processing power. Now if we look at the 3DMark2005 benchmark on Tom's we see that the standard 6800 Go (Depending on what dell clocks them at) is beating out a 3.2 desktop with an X800 in it (majority). Now, you are not choosing the 2.13 or 2.0 processor, so that would hamper the score somewhat, but all in all, I think It will be equal to or slightly faster than your current desktop (My guess would be faster). Should be nice man.
Ok, this is just a little theoretical detective work trying to answer your question best as I can, but of course, it is still based of online reviews. Best of luck.
Video Card comparison on Hothardware
From the max bandwidth let's just assume that the standard 6800's and the standard X800 are pretty close in processing power. Now if we look at the 3DMark2005 benchmark on Tom's we see that the standard 6800 Go (Depending on what dell clocks them at) is beating out a 3.2 desktop with an X800 in it (majority). Now, you are not choosing the 2.13 or 2.0 processor, so that would hamper the score somewhat, but all in all, I think It will be equal to or slightly faster than your current desktop (My guess would be faster). Should be nice man.
Ok, this is just a little theoretical detective work trying to answer your question best as I can, but of course, it is still based of online reviews. Best of luck.