I have Dell Inspiron 1720 laptop Core 2 Duo 2.00GHz T7250 CPU and 4GB RAM.
I would like to upgrade the CPU.
I was adviced that some unspecified 3.4GHz is the top CPU I can have, and it would only cost me about £80.
However, on some forums I read the max I can have is 2.8GHz X9000, but the following two CPUs would be more recommended for their price, efficiency, fan and battery saving.
Would you be able to help me out with the decision?
First off yes if this was a desktop computer $80 would be around the price of a CPU but mobile CPU cost almost 3 to 4 times as much as their desktop equivalents.
Laptops are not the easiest to upgrade just because the CPU might fit in the socket does not mean it will work. There has to support written into the bios for the CPU to work if its not it wont work so if Dell never made a bios with whatever processor you pick then it just wont work. I noticed that laptop came with 2 different chipsets it either has GM 965 or PM 965 so download CPU-Z from www.CPUID.com and see what exact motherboard is in your laptop.
The highest clocked core 2 made was 3.06 ghz so wherever you got your info from they have no clue what they are talking about.
You are limited to 800mhz FSB with you laptop and to be honest with you their will be barely any noticeable increase in performance to make it worth upgrading the CPU my advice is to just save up for a new laptop if you are really unhappy with its performance.
The X9000 might work but like I said before Dell would have to have written in support for it and I am gonna give you a warning expect to drop some serious cash finding that processor.
The best that I am finding is the T7700 at 2.4GHz. There are 2 things that this will depend on. First you need to get the latest bios for your motherboard, which will tell you all the chips that it can support. The best chip listed there is the best chip you can put in because it is the best chip that the system will recognize. Second you will have to worry about the extra heat generated by the newer cpu. It is not exactly easy to upgrade a laptops cooling system; you normally just go with what you have.
My suggestion it so avoid upgrading your laptop because it will be difficult to do, provide minimum gain, and could cause your system to run unstable. Save your money to buy a new laptop.