Intel Core i7-2640M vs Intel Core i5-430M

Intel Core i7-2640M

The Intel Core i7-2640M is the fastest dual core processor at the time of introduction in Q3 2011 and successor of the slower clocked i7-2620M. It is based on the Sandy Bridge architecture and offers Hyperthreading to handle 4 threads at once (for a better usage of the pipeline). Compared to the slower Core i5, the i7 offers a larger last level cache of 4MB. The base clock speed is 2.8 GHz but due to Turbo Boost it can reach 3.3 GHz (2 cores active) and 3.5 GHz (1 core active).

The 35W TDP rating includes the integrated GPU and memory controller.

Intel Core i5-430M

The Intel Core i5-430M is a fast middle class dual core CPU for laptops and clocks (due to the Turbo Mode) from 2.26 to 2.53 GHz. Each core is based on the Nehalem (Westmere) micro-architecture. Hyperthreading enables the Dual Core CPU to handle 4 threads at once (for a better usage of the pipeline). Compared to the faster Core i7-620M, the 430M only has 3 MB Level 3 Cache, missing VT-d, Trusted Execution, and AES features and a lower clock speed.

A feature of the new Core i5-430M is the integrated graphics card (called Intel HD Graphics) and memory controller. Both are on a separate die that is still manufactured in 45nm whereas the CPU die is already manufactured in the new 32nm process.

Due to the integrated memory controller, the HyperThreading and Turbo Boost, the  Core i5-430M is faster than a similar clocked Core 2 Duo in all (us known) applications and benchmarks. In fact, the 430M even came close to a fast Core 2 Duo T9600 (2.8 GHz) in some benchmarks (e.g. Cinebench 10 Multi Threaded). This means the 430M is a fast middle class - performance CPU and much faster than the top AMD model, the Turion II Ultra M660 (at the time of announcement).

The 32nm cpu cores of the Westmere generation can also process some new instructions to accelerate AES encryptions. Still, these functions are deactivated on the Core i5-430M leading to some performance drawbacks in modern applications that support AES encoding using the new instructions (e.g. the Communications Suite test in the PCMark Vantage boosts up to 70% using AES in the faster Core i5-520M).

The integrated Intel Graphics Media Accelerator HD (GMA HD) graphics card is between 500-766 MHz (Turbo Boost) and is clearly faster than the old GMA 4500MHD. A GeForce 9400M (ION) should still be a faster (especially as Nvidia and ATI cards have a better driver support than Intel up to now). The Turbo Boost can overclock the Intel HD Graphics up to 733 MHz when the cores are not fully used.

The power consumption of 35 Watt TDP (max.) counts for the whole package and therefore it is clearly better than the 35 Watt TDP of the Core 2 Duo T-series (CPU alone).