I have been doing some research. I need a new cpu for my Acer laptop. At this moment, it is running on a Pentium 6100. It's TDP is rated at 35W. I have finalised two cpus which I might be interested to acquite in replacing the Pentium 6100. The first candidate would be the Intel Core i5 520M and the other will be an Intel Core i7 620M.
There are not much of a difference between the two saved for the Core i7 620M's raw speed is 2.67Ghz with 4MB L3 cache and 2x256KB L2 cache. On the other hand, the Core i5 520M runs on a stock speed of 2.4Ghz with 3MB L3 cache and 2x256KB L2 cache. On turbo mode, the Core i5 520M could reach a speed of 2.933Ghz. The Core i7 620M could achieve a turbo speed of 3.333Ghz. Both share the same TDP at 35W.
Another factor to take into account would be the price. The Core i7 620M is priced around £130 for a second hand unit where else for the Core i5 520M, you could easily get it around the £100 mark for a second hand unit. In such a case, you would have to take into account what's the benefit of having a Core i7 over a Core i5? Would it justify getting the Core i7 620M as it has 1MB L3 cache more than the Core i5 and with turbo, the Core i7 620M can achieve 3.333Ghz! That is fast. Bear in mind that the 3.333Ghz would only exist if it runs on a single core and it is automatic. The question here is whether it is justified to have the Core i7?
From the many articles which I have read here and here, it looks as if the Core i7 cpu is not justified though. I think I will stick with the Core i5 520M instead. It is relatively cheaper than the Core i7 and it does not draw so much energy as their Core i7 counterpart. I wonder whether I will still get the 8 hours on a single charge with the Core i5 520M cpu or should I just stick to my Pentium 6100?