Mac Pro 3,1 for FCPX

I just purchased a 2008 Dual Quad Core Xeon 2.8 for $450. I'm hoping to put together a video editing system for a reasonable sum.

By far, the largest reason for buying this is to migrate to FCPX.

I need some good advice on upgrades. Keep in mind I already know I'm wanting a single large 4K monitor and camera in about a year.

It's got 12 GB of Ram.

I already purchased a USB 3.0 card and considering a flashed HD 7950 video card at a current used price around $230, along with increasing to 16 GB of ram, and adding a small SSD for the OS.

Unless the drivers were improved in Yosemite 10.10, the 7970 has a very large reduction in performance with the 3,1

Is the 3,1 up to the task or should I futz around for a bit then look for a 12 core machine?

I think the 12 core would be overkill. You could spend the extra money on other things that would help out much more than more CPU cores.

Pcola,
Congratulations on your new (used) MP, and welcome to the FCP.co forums.
I think the legacy MPs have a lot of life in them and for folks who like to do their own mods and upgrades it is the machine to have, IMHO.
Your proposed mods are quite reasonable, but stuff in as much ram as you can. You do not say what type of video and codecs you will be using, this is the place to start when deciding system needs.
A ssd boot drive or a PCIe flash drive are good places to start, then you can RAID a couple of internal drives for media or add external drives via USB3. (Make sure it is USAP enabled not just BOT protocol)
As to video cards, lots to now choose from. You can also add a second vid card to increase speed too if you need the extra horsepower. Check out this thread here for some insight… www.fcp.co/forum/hardware/18250-brucex-t...-cut-pro-x-benchmark
Here are some sites I like…
Larry Jordan has a good article on configuring your system… www.larryjordan.biz/app_bin/wordpress/archives/2559
Barefeats does some great comparisons between lots of different configurations including using different GPUs… barefeats.com Great site when you want to compare various system configurations.
DigLloyd has some good comparisons as well… macperformanceguide.com Be sure to explore the site.
And finally I like some of the articles @ create.pro/blog/ They really push cutting edge legacy MPs as the best system for video editing.
Happy Editing
Hope this helps, Greg