Which i7 CPU for new laptop

Go for the quad-core, since video and picture editing is multithreaded the quad core will help a lot..

However, Photoshop tends to like more Ram over a better CPU.

If you can find a i5+6/8GB setup for less than the i7, go ahead with that. The i5 is quite a strong processor, stronger than the i7 in single-threaded apps due to its higher clocks actually. It will also run cooler and have a longer battery life.

Thanks for the replies guys. I've found a Dell with a i5-540M (2.53GHz, 3MB cache) and 6GB RAM for a similar price, are you saying that you think this would suit my needs better than either of the i7s?

On another note, would anybody be able to tell me what effect (if any) the size of the graphics card has on video rendering and image manipulation, as I have found some cheaper laptops with 512MB graphics instead of the 1GB I am currently looking at.

Additionally, would a 7200RPM HDD show a noticable improvement for my needs over a 5400RPM one? (Unfortunately a solid state drive would not really be an option as i require a large capacity internal drive (>500GB) for my video requirements.

Many thanks

The 7200RPM drive spins faster than the 5400RPM drive, theoretically increasing performance at the cost of more power. As to the graphics card RAM size has little to do with actual performance, its the GPU inside that counts. As to the core i5 I have to disagree with Timop as the Core i7 can scale almost as high as that i5 you just mentioned on single-threaded aps. However if you have well-threaded apps the quad again is the way to go.

Not quite, as a Photoshop user myself, more RAM really help when youre working with huge files+many layers, as for processing even a 5200+ that I have can handle things fine. The only place where intense CPU power is needed is applying filters, which is not nearly as important as smoothness when you have 50+ layers on a RAW file.

Simply put, with editing (both video/image) plenty of RAM and a fast HDD is preferred. While for processing/encoding, it will benefit more from a quad.

Though contrary to what you said, the i7 can go only as high to a 2.5Ghz dual when the other 2 is dormant (meaning no background apps), while almost all the time the i5 can become a 2.9Ghz dual (The i7 dual core is a 3.2Ghz + more L3), 400Mhz isn't nothing.

However, what prices exactly are those laptops? You should be able to find i5+6GB+ laptops for quite a less than i7 ones.

The i7-740QM one with 4GB ram was a £977 Dell Studio 15, and the i5-540M one with 6GB ram was a £974 Dell Studio 15.

There are some comparable ones on pcspecialist, specifically the i7-640M one with 4GB ram and a 7200RPM HDD, coming to £964 (although this is an 18 inch model so really isn't a fair comparison).