Should I upgrade? from 1 - 2gb
 

Right now my old laptop uses 512 mb of ram in two slots making 1024 mb. They are both clocked at 333mhz and they are ddr2. If I upgrade to two 1 gb sticks at 667 mhz could I expect to see twice the performance? or at least a noticeable difference?

also the computer uses PC2-5300 can i use PC2-6400 instead? 667 and 800mhz ram is close in price i think

You know there are different flavours of DDR3, that a ram slot that runs at 333mhz most likely will not support ram running at 667mhz. What is the laptop model?

Oh it's an old acer aspire 5315 and i know it will upgrade because i have found lot's of information online that it will not to mention the fsb is 800 mhz it should. It is just the memory that came with it and in my experience the ram that comes in commercially built computers has the WORST clocks on the memory. My parents computer boasts 6gb of ddr3 but it only runs at 667 mhz because acer wanted to skimp on that.

I don't know where you read that and would to see a link to it since according to acer's website our laptop's fsb is 533MHz, not 800Mhz Acer Support - Aspire 5315 Series Specifications

Higher-rated RAM will run fine in your laptop; it will just be set to whatever speed the chipset needs it to run at. As far as performance improvements, going from 1GB to 2GB should give you a pretty large boost.

Really depends on your laptop and how much memory it can actually take advantage of. Certain memory will work while others may not. Yes you can use faster memory, but your laptop may just downclock it.

DDR3? :whistle:

Sorry I was thinking of my other laptop. I just looked at CPU-Z and it says 533mhz. So I assume having a lower fsb then the ram is clocked for is bad ?

You need to figure out the exact model.. Corsair lists a few different models.. after the 5315 what is the next number?

The model number is ICL50

No, there's nothing bad about it at all.