So it may be imperative to conclude that the Core i7-2630qm is substantially faster than the Core i7-740QM and if you have a choice the Core i7-2630qm, based notebook is good even if it is $150 or so more than the core i7-740QM. The Sandy Bridge processors are about 10 to 15% faster than the similarly clocked Clarksdale processor.
Another processor that is good to compare clock by clock frequency is the core i7-920XM – a 2 GHz quad core processor. With slight improvement in the architecture we can expect that the Core i7-2630qm processor performance is on par or better than the Core i7-920XM Quad Core processor.
The more noticeable improvement, or rather difference is in the integrated graphics section ( it is called Intel HD Graphics 3000). The Sandy Bridge graphics has been found to have 100 to 125% improved performance as compared to the Intel HD graphics. The core i7-740qm does not has integrated graphics.