Intel Core i7-2649M vs Intel Core i7-2640M vs Intel Core i7-2677M

Intel Core i7-2649M

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 i7-2677M

The Intel Core i7-2677M is power efficient ULV (Ultra Low Voltage) processor for thin and light laptops. The base frequency of 1.7 GHz is relatively low, but due to Turbo Boost 2.0, the CPU may clock up to 2.8 GHz (one core loaded, 2.5 GHz with both cores loaded). However, this depends on the cooling and power consumption of the laptop. Due to HyperThreading, the i7-2677M is able to handle 4 threads in parallel.

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

The integrated Intel HD Graphics 3000 clocked at 350 or 1200MHz (Turbo Boost). Due to the slower clock rate without the Turbo, compared to HD Graphics 3000 in 35W and 45W processors (usually clocked at 650 base speed in non LV processors), the performance should be noticeable lower.

The performance of the CPU should be a bit higher than a similar clocked Arrandale Core i5. Thanks to the high Turbo Boost frequencies, the performance should be similar to the Core i3-2330M. However, the laptop cooling system has to keep the processor relatively cool for the Turbo Boost to work often.

The TDP of 17W (includes the integrated GPU and memory controller) allows the use of the 2677M CPU in small subnotebooks.