I have found that noise reduction and lens correction are the biggest slow-downs. Try an image without using these, and tell us if it's just as slow.
It is a VERY compute-intensive process, and to be fair the D800 has quite a large number of pixels.
That said, Adobe seems to be struggling a bit to get all your processor cores working as efficiently as possible in tandem on the task. It's no small feat to get multi-threading just right. Beyond that, I don't think they're using GPU acceleration in the process yet.
You might want to have a glance at these threads re: Camera Raw performance:
http://forums.adobe.com/message/4835211 (post 7 discusses D800 conversions specifically)
It's important to determine whether you have a specific problem or are just seeing the more or less typical computing overhead. If you have a specific image with specific settings and would like to put the .NEF/.XMP combination online - or just describe in detail what you're doing and precisely how long it takes others could relate their experiences.
Thanks for the replies. I'm fairly certain its jus the computing overhead that's the problem, slowish for every file I work on. It always seems like its having trouble loading the file, taking so long.
I took a look at the threads and yeah I'm in the boat as the first guy.
I guess there isn't any other way of boosting performance options, maybe I'll pray that Adobe gets an update out there, cause right now, its pretty brutal in certain spots when editing.
That first discussion link is reported missing now. I'm losing track of all these discussions about poor Camera Raw and Bridge performance.
I'm back after radio silence, having replaced my PC mainboard and reinstalling all of my software. I'm now running an overclocked i7-3770K with 16GB RAM and processing raw D800 files. It certainly feels very snappy. I'm ready to do some more benchmarks.