Intel Core i7-2640M vs Intel Core i5-460M

Sandy Bridge is the evolutionary successor of the Arrandale architecture. The most noteable improvements are the new 256Bit AVX instructions, the improved Turbo 2.0 and the integration of the graphics card into the 32nm CPU core. 

Der i7-2640M offers an integrated graphics card ( Intel HD Graphics 3000) which is clearly faster then the older Intel HD Graphics in the Arrandale CPUs. As the new GPU is included in the CPU, it is also manufactured in 32nm and shares the fast level 3 cache with the CPU cores (using a new ring bus). In the 2620M it is clocked from 650-1300MHz (Turbo Boost), and in the 2640M it should be similar.

Furthermore, an improved dual-channel DDR3 memory controller is included on the CPU die that is used by the CPU and GPU part.

Due to the improved architecture and the new Turbo Boost 2.0, the average performance of the Core i7-2640M is higher than a similar clocked Arrandale Core i7 dual core. The performance should even excel the old high-end quad core models like the Core i7-820QM.

The Intel Core i5-460M is a high end dual core CPU for laptops and clocks (due to the Turbo Mode) from 2.53 to 2.8 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 Core i5-540M, the 460M does not support AES, VT-d and Trusted Execution functions and features a slower Turbo Boost (2.8 versus 3.06 GHz).

A feature of the new Core i5-460M is the integrated graphics card called GMA HD 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.

The performance of the Core i5-460M is on average faster than a 2.8 GHz Core 2 Duo T9800 and in some benchmarks even faster than the fastest Core 2 Duo T9900 (e.g. 3DMark 06 CPU Score). Therefore, the Core i5-460M is a high end dual core cpu which should handle all daily work and gaming tasks. Only the quad core i7 CPUs can be noticeably faster at tasks that require four or more threads (e.g. rendering).

The integrated Intel Graphics Media Accelerator HD (GMA HD) graphics card is known to be clocked up to 500-766 MHz and should be 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). According to rumors, the GMA core will also use the Turbo Mode regulate the clock speed.

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). Due to the Turbo Boost, the Core i5 is likely to use the whole TDP of 35 Watt under load and therefore can use more power than a similar specified Core 2 Duo. In Idle mode, the i5 uses clearly less power than the Core 2 Duo CPUs.