Faster CPU or better GPU.

Graphics card is more important for games. The 5870 will give you a more noticeable difference.

Thanks for your quick reply  

So the better GPU is the choice to go for even though the i5 450M gives roughly 400MHz higher clockrate in turbo mode?

I think you mean the i5 540M. The one thing to keep in mind is that the max TurboBoost speed is only applied when one core is being used. More and more games are taking advantage of multi-core processors, so the likely hood of actually getting the full boost is pretty low with most current titles. Also, TurboBoost is thermally restricted. If temps are too high, it will not engage to the fullest extent or at all.

But for the most part GPUs play a far bigger role in gaming then the processor. This is especially true at higher resolutions (1680x1050 or above). Lower resolutions may depend a little more on the CPU, but most dual cores are able to handle it.

Out of curiosity, what two laptops are you looking at?

Nice answer, thanks man.

http://www.prisjakt.nu/produkt.php?j=628243,567415 shows a comparison between the two. Damn hard to choose. What I like more about the HP with the 5850 is the fullHD resolution, the keyboard and the general design. On the other hand FullHD resolution on such a small screen might be a bit to exaggerated. It is hard to determine how much the difference will be in performance, but it is as you say, the noticeable difference will show in high resolutions, 4xAA, ultra settings, etc.

The site is in swedish but you'll figure the important things out  

Which one would you prefer?  

You can find benchmarks for the two here: http://www.notebookcheck.net/Computer-Games-on-Laptop-G...

The difference isn't huge, but it's there. The combo of the 5870 and the lower resolution screen will actually give you higher frame rates. The MSI would still be my choice.

Great.

Cheers mate!