What computer is better?

The Alienware X51 has slightly better specifications such as 1600mhz RAM vs 1333mhz, has a 2% better performing CPU in the benchmarks, but the FX-6300 in the CyberpowerCP has a higher clock speed and an additional 8MB L3 cache. The Alienware x51 has slightly better Video but you'll need a PCIe video card on any of the two. The PSU is better on the CyberpowerPC but you'll have to upgrade it for gaming on any of the two. The case on the Alienware is the Dell small non-standard Form Factor as well as the motherboard so forget it's upgradeability, and it's $260 Dlls more than the CyberpowerPC, so I'd put-up those $260 to push the CyberpowerPC's slight defficiencies far above the Alienware... or simply OC it's CPU and RAM slightly and get a better PSU and CPU cooler, and save $100.00>.

CyberpowerPC Gamer Ultra 2165 Desktop PC AMD FX-Series FX-6300 (3.50GHz) 8GB DDR3 1TB HDD Capacity Windows 8.1 64-Bit
http://www.newegg.com/Product/Product.aspx?Item=N82E16883229437

DELL Alienware X51 (AX51R2-5730BK) Desktop PC Intel Core i5 4440 (3.10GHz) 8GB DDR3 1TB HDD Capacity Windows 8
http://www.newegg.com/Product/Product.aspx?Item=N82E16883155877

AMD Radeon R7 250 2GB VS NVIDIA GeForce GTX 645 1GB GDDR5
http://www.game-debate.com/gpu/index.php?gid=1866&gid2=894&compare=radeon-r7-250-2gb-gddr5-vs-geforce-gt-645