The minimum requirements to run Unity as follows:
MINIMUM:
Processor: Intel Core i5-2500K @ 3.3 GHz or AMD FX-8350 @ 4.0 GHz
Memory: 6 GB RAM
Graphics: NVIDIA GeForce GTX 680 or AMD Radeon HD 7970 (2 GB VRAM)
Hard Drive: 50 GB available space
and that's not even the recommended requirements, that's minimum. Ridiculous if you ask me. Plus I've heard that there are many bugs and glitches. I might wait a few weeks, maybe a month for ubisoft to patch things up a bit before buying.