Intel Core 2 Duo SL9600 vs Intel Core i5-540M vs Intel Core 2 Duo T9550

Intel Core 2 Duo SL9600

The Intel Core 2 Duo SL9600 is a low power laptop processor for small and slim laptops. It features the full 6 MB level 2 cache and all features of the Penryn core (e.g. VT-x and Trusted Execution). Due to the large cache, the CPU shows a good performance for the small clock rate. However, in the MacBook Air, the CPU throttled very often, leading to the slower benchmarks in our database.

Compared to other Core 2 Duo models, the C2D SL9600 only supports the socket BGA956 and is soldered in the MacBook Air models.

Intel Core i5-540M

The Intel Core i5-540M is a mid-range dual core CPU for laptops and clocks (due to the Turbo Mode) from 2.53 to 3.06 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 540M only has 3 MB Level 3 Cache and a lower clock speed.

A feature of the new Core i5-540M 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 i5-540M 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 i5-540M 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 32nm cpu cores of the Westmere generation can also process some new instructions to accelerate AES encryptions.

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.

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).