The core i5m is a midrange dual core processor with HT that you will find in most of the new Notebooks in the market. These are similar to the i3 but have a higher core clock and also a higher GPU clock.

This processor has many variants ranging from the Core i5 - 430M(2.26GHz,2.53GHz under Turbo) to core i5-540M(2.53Ghz,3.06GHz under turbo).
They all have 3MB of L3 cache and support dual channel DDR3 up to 1066MHz. These also have a TDP of 35W and the GPU runs at 766MHz.

The turbo mode is an additional feature here. It basically means that in single threaded applications, i.e. they use only one core, the processor automatically switches off the extra cores and uses that power to increase the clock speed of that one active core. Hence it speeds up the single threaded applications.

In these processors also, the older FSB has been replaced with the newer DMI and hence this reduces the memory latency. They also have an onboard PCIe controller.

If anyone here has used a laptop with this processor, please do let us know what you think about it, if you have benchmarked it, do feel free to post them here or link it. You can have a look at the benchmarks of the core i7m i had reviewed earlier here. (XPS 16 - Full review Finally !!)