8 core mac pro

[SPdavid87]

I've spotted this deal online.

2.4 8 core for £2k

Kinda attracted to it with the exception of the gpu.

What'd be the best graphics card to replace that 5770 with?

If i upgraded it to ML would something like a 560Ti work out the box?

would a single cpu 6 core be faster?

 

[derbothaus]

There is a literal library of info on the front page for these questions. But summarizing:
The 6-core is mathematically and always faster (by a ton or by a small margin depending on task and software) unless you need to utilize more than 32GB of memory on a regular basis. A 560ti is not much of an upgrade if you ask me. Get a 570 and now you are in business. But they are not officially supported and have caveats. See every post on the subject on the front page.