I want to purchase new computer, I want to know the best specification to get best performance PC?

first must choose a motherboard like MSi 

second you must choose a good processor like I5

third RAM like8GIGA and HDD GIGA

what do you mean the best performance?? do you mean the best ever existing or what ??

any way there is a specs for one of the best performance computer  Cpu : intel core i7,4th generation , ram:Gb, hard drive:2To,  Gpu:2gb (at least) , windows8.1 pro. for more information:4

i7 processor, minimum4 GB RAM, min2.0 GHz cycle speed processor, minimum2 GB dedicated graphics card.

 Intel® Core™ i7-K Processor (6-cores,MB Cache, Overclocked up to3.9 GHz w/ Turbo Boost)

GB Quad Channel DDR4 atMHz

GB SSD6Gb/s Main +4TBRPM SATA6Gb/s Storage

Intel.ac2x2 Wireless, WiFi and Bluetooth4.0

MSI made Alienware X Motherboard

Triple GTX (nVIDIA OEM)

now that's monster specs