Intel Core 2 Duo SL9400 vs Intel Core 2 Duo T9550 vs Intel Core 2 Duo T6400

Intel Core 2 Duo SL9400

The Core 2 Duo SL9400 is a power saving low voltage CPU for thin and light laptops. It offers a good performance for the 1.86 GHz clock rate, as it features the full 6 MB level 2 cache of the used Penryn core.

Intel Core 2 Duo T9550

The Intel Core 2 Duo T9550 was the middle class dual core CPU for laptops at the time of introduction. It is similar to the Core 2 Duo P9600 except for the higher TDP of 35 versus 25 Watt.

Due to the relatively high clock speed and 6MB Level 2 cache, the T9550 offers enough performance for demanding games (in 2009) and applications. 

The T9550 uses a Penryn (Montevina Update) core that features 2 integer units, 1 floating point unit, 1 load unit, and 1 store unit in a 14-stages long pipeline. Due to the Wide Dynamic Execution Technology, the core is able to simultaneously execute up to four instructions.

The integrated Enhanced Speedstep is able to downclock the core dynamically to save power (in idle mode).

Intel Core 2 Duo T6400

The Intel Core 2 Duo T6400 is an entry level dual core processor for cheap laptops. It is based on the Penryn core but offers only 2 MB level 2 cache and a slow clock speed of 2 GHz. The performance should be sufficient for office and other casual tasks but high level gaming and HD video editing for example could be limited by the CPU performance.