Both of those are going to require some upgrades for what you want but they would be the starting point. See if you can budget a 760GTX card and that would go a long way to your goal.
Take a look at our Premiere Pro Benchmark.(PPBM) To see the results page you will have to register. The "H.264 test " timeline contains three segments of 4k material that is exported out to 1920 x 1080 resolution. On the results page you can see how long it takes to export that timeline. Be aware that the new CC 2014 results are almost twice as fast over CC or CS6 because of major improvements in the 4K processing, You have not mentioned what version you are using.
When you look at the Speccy file (Speccy - Download) it will show you the hardware configuration of each of the computers
Look at the Tweakers Pages, you might be able to back off from those recommendations if as you say you are only going to export to lower resolution.but as Eric said make sure you have an nVidia card like he recommends but I would suggest that since vyou are handling 4K you get a 3 or 4 GB video card....
I suspect that if you select your system carefully you will be able to do 4k editing without having to pre-render anything.
First of all, not all 4k is created equal. Red 4k could be liked to compressed RAW and is pretty rough on a system. From some cursory playing though, with CC 2014 it does appear to be much more manageable than with previous Premiere Pro releases. [Sidebar, who can explain what is new / different, I'd love to know]
Using a couple year old x79 6-core, 24GB RAM, GTX 480 1.5GB video card I can play back Red 4k without rendering, at full resolution Adobe setting (not to a 4k monitor though), and I'm seeing zero dropped frames. CPU is about 80% loaded and GPU was about 65% loaded.
Now, when I play back Sony AX100 4k footage, which is highly compressed and far from RAW, 4k playback at full resolution is also free of any dropped frames and both the GPU and CPU are loafing along compared to the Red 4k load (GPU 14%, CPU 20%). I cannot promise since the GH4 and AX100 do use different CODECs that your results will be the same, but both are highly compressed, somewhat lossy 4k media, and I would expect they would be in the same ballpark.
- get a budget 6-core, good deal on a matching Asus MB, 32GB RAM, GTX 770 2GB video card, 256GB boot SSD (Crucial M550), and as many Crucial M550s as you can afford for the rest of your build
Finally, render outputs from Red 4k to HD 1080p are about 3/4's real time and for the AX100 1x real time (i.e. 60 seconds for 60 seconds of footage) on this same system and CPU is 95% loaded for exports with GPU about 65% loaded.
Thank you for all the feedback guys! You pretty much reaffirmed my belief that the stock asus systems were not going to be enough to handle the toll as easily as I had hoped especially with the stock gpu. In other words I needed to go ahead and spend the extra money for something a lot more powerful and a little more time proof. I have assembled a machine that should met all criteria for my 4k editing (I hope) and is a few hundred dollar over my budget but like I said I would pay more for quality. I focused on cpu and gpu more than anything and from your suggestions Eric and Jim I decided to go with the 780 ti. This build is something I want to last for a while so that is my thoughts behind going ahead with a larger budget.
Bill I am a recent graduate and was paying for CC student edition that expired this month. So I will be getting CC 2014 in its latest version as soon as the build is complete. I took a look at the benchmark and kind of used it as a base for this build.
Jim thank you for the insight on the 4k compression vs Raw, that was in the back of my mind but I was not certain on how that affected processing and rendering on the computer.
So here is what I have put together. Please, feel free to correct me on any parts that may lead to a better deal or better quality. I am right under $2000 and would like it to keep it that way. If you have a cheaper solution by all means share! I'm not an expert on computers so some of the parts may have better options? Also if in the future I want to go SLI the 750w power supply should cover it? Is it better to go with a full modular supply opposed to non modular, if it even matters since it is mainly cable management?
Your price point is OK, but you need to move about $400 of your budget from your video card into RAM, CPU, and motherboard.
Go with a i7-4930k 6-core, 32GB of RAM, GTX 770 2GB instead.
Re-read the cpu/gpu loads above and you will see that for 4k CPU is very important.
Why do you want a water cooled heat sink, go with a Coolermaster Hyper 212+ EVO and save money
You do not necessarily need a sound card
Really follow Jim's suggestions