Intel Core i7-2649M vs Intel Core i7-2640M vs Intel Core i7-2920XM
Intel Core i7-2649M► remove
The Intel Core i7-2649M is power efficient LV (Low Voltage) processor for laptops. The base frequency of 2.3 GHz is relatively low, but due to Turbo Boost 2.0, the CPU may clock up to 3.2 GHz (one core loaded, 2.9 GHz with both cores loaded). However, this is depending on the cooling and power consumption of the laptop. Due to HyperThreading, the i7-2649M is able to handle 4 threads in parallel. Compared to the similar called Core i7-2620M, the 2649M is slower but also needs less power (25W versus 35W TDP).
Sandy Bridge is the evolutionary successor of the Arrandale architecture. The most noteable improvements is 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 500 or 1100MHz (Turbo Boost). Due to the slower base clock rate, compared to HD Graphics 3000 in 35W and 45W processors (usually clocked at 650), the performance should be a bit lower.
The performance of the CPU should be a bit higher than a similar clocked Arrandale Core i7 LV. Therefore, the performance should a bit above the Core i3-390M if the Turbo can be used often.
The TDP of 25W (includes the integrated GPU and memory controller) allows the use of the 2649M CPU in thin notebooks.
Intel Core i7-2640M► remove
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).
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 35W TDP rating includes the integrated GPU and memory controller.
Intel Core i7-2920XM► remove
The Intel Core i7-2920XM is the fastest quad-core processor for laptops in Q1-2011. Due to the Extreme Edition branding, the CPU should be easy to overclock (unlocked multiplicator). It is based on the Sandy Bridge architecture and offers Hyperthreading to handle 8 threads at once (for a better usage of the pipeline). Compared to the previous Clarksdale quad-cores, the i7-2920XM is now manufactured in 32nm, offers an integrated graphics card and AES functions. Compared to the slower clocked 2820QM, the 2920XM is specified with a higher TDP.
Sandy Bridge is the evolutionary successor of the Arrandale architecture. The most noteable improvements are the new 256Bit AVX instructions, the improved Turbo Boost and the integration of the graphics card into the 32nm CPU core. Furthermore, the integrated memory controller was improved and supports up to 8 GB DDR3-1333.
The Core i7-2920XM offers an integrated graphics card (Intel HD Graphics 3000) which proved to be clearly faster than the old Intel HD Graphics in the Arrandale CPUs and on a level with entry level dedicated graphics cards like the GeForce 310M. The HD Graphics 3000 also supports Turbo Boost and clocks between 650 MHz and 1300 MHz. As the graphics card shares the fast last level cache, the processor is a bit slower with activated GPU.
Due to the high Turbo Boost and Hyperthreading, the performance of the Core i7-2920XM can reach levels of the fast desktop Core i5-2500K processor. Compared to the previous generation, the i7-2920XM is up to 42% faster than the old Core i7-940XM processor. Therefore, the performance should be sufficient for even the most demanding tasks like HD video editing or 3D games. Extensive benchmarks can be found at the end of this page and in our review of the new Sandy Bridge quad core processors.
The high TDP rating of the 2920XM enables the usage of the quad core only in large and heavy laptops (usually 15" and up). Compared to the previous generation of quad-cores, however, the TDP improved, as the integrated GPU is now included.
|Intel Core i7-2649M||Intel Core i7-2640M||Intel Core i7-2920XM|
|Intel Core i7||Intel Core i7||Intel Core i7|
|Sandy Bridge||Sandy Bridge||Sandy Bridge|
|: Core i7 Sandy Bridge|
|2300 - 3200 MHz||2800 - 3500 MHz||2500 - 3500 MHz|
|128 KB||128 KB||256 KB|
|512 KB||512 KB||1 MB|
|4 MB||4 MB||8 MB|
|2 / 4||2 / 4||4 / 8|
|149 mm2||149 mm2||216 mm2|
|100 °C||100 °C||100 °C|
|HD Graphics 3000 500-1100MHz, integrated DDR3-1333 memory controller, Virtualization, Trusted Execution, Hyper-Threading, Turbo Boost 2.0||HD Graphics 3000, DDR3-1066/1333 Memory Controller (max 8GB), HyperThreading, AVX, Quick Sync, Virtualization||HD Graphics 3000 (650-1300MHz), DDR3-1066/1333/1600 Memory Controller, HyperThreading, AVX, Quick Sync, Virtualization|
|iGPU||Intel HD Graphics 3000 (500 - 1100 MHz)||Intel HD Graphics 3000 (650 - 1300 MHz)||Intel HD Graphics 3000 (650 - 1300 MHz)|
|Intel Core i7 2649M||Intel Core i7 2920XM|
|$346 U.S.||$1096 U.S.|