How We Tested & Bandwidth

AMD has supplied us with its top-end FX-8150 processor for testing. Thankfully, the FX range is unlocked and the Asrock Fatal1ty 990FX motherboard allowed us to enable just six, four or two cores. This board also allows customization of the Turbo Core and Max Core multiplier. This allowed us to mimic the performance from the lesser three FX processors launching today: the FX-8120, FX-6100 and FX-4170.

AMD AM3+ Test System Specs
- AMD Phenom II X6 1100T (3.30GHz)
- AMD Phenom II X4 980 (3.70GHz)
- AMD FX-8150 (3.60GHz)
- AMD FX-8120 (3.10GHz)
- AMD FX-6100 (3.30GHz)
- AMD FX-4170 (4.20GHz)
- x2 4GB G.Skill DDR3 PC3-14900 (CAS 8-9-8-24)
- Asrock Fatal1ty 990FX Professional (AMD 990FX)
- OCZ ZX Series 1250w
- Crucial m4 256GB (SATA 6Gb/s)
- Gigabyte GeForce GTX 580 SOC (1536MB)
Software
- Microsoft Windows 7 Ultimate SP1 64-bit
- Nvidia Forceware 285.38

Intel LGA1155 Test System Specs
- Intel Core i7-2600K
- Intel Core i5-2500K
- x2 4GB G.Skill DDR3 PC3-14900 (CAS 8-9-8-24)
- Gigabyte G1.Sniper2 (Intel Z68)
- OCZ ZX Series 1250w
- Crucial m4 256GB (SATA 6Gb/s)
- Gigabyte GeForce GTX 580 SOC (1536MB)
- Microsoft Windows 7 Ultimate SP1 64-bit
- Nvidia Forceware 285.38

Intel LGA1366 Test System Specs
- Intel Core i7-975 Extreme Edition (3.33GHz)
- Intel Core i7-920 (2.66GHz)
- x3 2GB G.Skill DDR3 PC3-12800 (CAS 8-8-8-20)
- Gigabyte G1.Sniper (Intel X58)
- OCZ ZX Series 1250w
- Crucial m4 256GB (SATA 6Gb/s)
- Gigabyte GeForce GTX 580 SOC (1536MB)
Software
- Microsoft Windows 7 Ultimate SP1 64-bit
- Nvidia Forceware 285.38

Intel LGA1156 Test System Specs
- Intel Core i5-750
- x2 4GB G.Skill DDR3 PC3-12800 (CAS 8-8-8-20)
- Gigabyte P55A-UD7 (Intel P55)
- OCZ ZX Series 1250w
- Crucial m4 256GB (SATA 6Gb/s)
- Gigabyte GeForce GTX 580 SOC (1536MB)
- Microsoft Windows 7 Ultimate SP1 64-bit
- Nvidia Forceware 285.38

Compared to the Phenom II, AMD's FX processors provide significantly more memory bandwidth. Read throughput has been increased by roughly 60%, while write performance is almost 40% better. Although the bandwidth performance has been improved greatly, it's still considerably slower than Intel's Sandy Bridge processors.

The L2 cache performance has also been improved -- at least when looking at the Phenom II range. The FX-8150 delivered 30% more read throughput than the Phenom II X6 1100T, though the write performance was slightly slower. As with the previous chart, Bulldozer just can't match Sandy Bridge's L2 cache performance.