I'm going to clear up the specifications a bit.
1.
i7 3820 4.2 GHz
2 X Radeon 7870
16GB DDR3
Two hard drives (total of 1.5 TB)
2.
i7 3770k 3.5GHz
Radeon 7950
16GB DDR3
120GB SSD
This is a difficult choice.
The 3770k CPU is newer, but the two are similar in performance.
http://www.cpubenchmark.net/high_end_cpus.htmlThe benchmarks are about 600 points off (not counting the overclocked 3820)
I'd say they offer the same amount of performance.
Both computers have the same amount of RAM.
Computer 1 has significantly more storage space than computer 2 (1500GB as opposed to 120GB).
For this, I would lean toward computer 1. However, an additional hard drive is not that expensive.
The graphics on the first computer is definitely better than the second one.
The Radeon 7870 clocks in at 4202 and the Radeon 7950 clocks in at 4540.
http://www.videocardbenchmark.net/high_end_gpus.htmlHowever, keep in mind that computer 1 has TWO of these graphics cards. That would definitely be the better choice.
Just looking at these specifications, I would go for the first computer.
However, we should know more information.
What are the prices of these computers? How far apart are they?
What do you plan to do with these computers?