I'm currently using a mid-2010 Macbook Pro with a i7-620M. I'm decided to buy a Gazelle Professional but I'm not sure how to compare the processors available, I mean (even if it sounds simplistic/silly/stupid) how fast is one compared to another.

Here, a comparison between my current processor and those offered with the Gazelle:

I'm decided for the i7-3740QM just because is 'in the middle', but I do not know if even the i7-3630QM is very much faster than my current processor.

Even if in my everyday tasks tasks I'm quite satisfied with my current laptop, I'm starting to learn photography, and GIMP and Darktable are not performing well. Also, I use GNS3 and some VMachines (VirtualBox) at the same times.

Thanks in advanced for any help!