AMD Phenom II X4 X940 BE vs AMD Phenom II X4 P920 vs AMD Phenom II X4 N950

AMD Phenom II X4 X940 BE

The AMD Phenom II Black Edition Quad-Core X940 or Phenom II X4 X940 BE is the fastest version of the Phenom II X4 for laptops (in Q1 2011) and features an unlocked multiplier for easy overclocking. With 45W TDP the AMD CPU needs as much power as the Core i7 quad cores but due to the missing level 3 cache and Turbo Boost, the performance should be worse. Compared to the desktop CPUs, the mobile Phenom II X4 is similar to a Athlon II X4 and produced in 45nm SOI.

The performance of the 100MHz slower predecessor Phenom II X920 differs from benchmark to benchmark. If only one core is used, the AMD quad core processor is only on par with a slow 2 GHz Core 2 Duo (e.g. Cinebench R10 Single). The old single threaded SuperPi benchmark is traditionally for AMD even worst on a level of a 1.4 GHz Core 2 Duo. However, if all four cores are used, the performance scores are in regions of the fast dual cores Core i5-540M to i7-640M (Cinebench R10 Multi, wPrieme 2, CB 11.5). The slowest Core i7 quad core (720QM) is still in every benchmark faster than the AMD CPU.

The Phenom II includes an integrated memory controller for DDR3 (max. 1333) main memory. It supports MMX, 3DNow!, SSE, SSE2, SSE3, SSE4A.

AMD Phenom II X4 P920

The AMD Phenom II X4 P920 is a slow clocked quad-core CPU for laptops. Compared to the desktop Phenom II, the mobile Phenom II X4 offer no level 3 cache and are therefore compareable to the desktop Athlon X4 line. The slow clock speed allows the low powerconsumption (25 W TDP) but may lead to a bad performance in single threaded applications and games. For example in the single threaded CB10 test, the P920 only was as fast as a 1.6 GHz Core 2 Duo Dual-Core. In SuperPi even a 1.3 GHz Core 2 Duo was faster. If all four cores are used, the CPU can be as fast as a 2.3-2.4 GHz Core 2 Duo (e.g. T4500). In CB11.5 even as fast as a Core i3-330M. The Core i7-720QM Quad-Core is also rated at 1.6 GHz, but due to Turbo Boost and a large level 3 cache, the 720QM is noticeable faster (and more power hungry).

As the current Intel Core i3 CPUs, the P920 offers an integrated DDR3 memory controller (up to DDR3-1066). However it is still manufactured in 45nm (SOI process).

AMD Phenom II X4 N950