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I am thinking about upgrading the ram in my laptop (currently 6GB, consisting of two, a 4GB and a 2GB, Ramaxel DDR3 SODIMM chips), but I am going to replace the 2GB chip with an 8GB Crucial Chip.

The new Crucial RAM and the Ramaxel RAM are both 1333MHz, so I think thats about everything (in terms of compatibility) checked, so are there any other factors i need to take into account?

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They'll work, but you won't get the best performance from unmatched RAM. However, since you don't have matched RAM anyway, you won't see a performance decrease. You'll still get the performance advantage from having more RAM.

DDR RAM works the fastest in dual channel mode, where you have 2 (or 4, etc) identical sticks. In this case identical means same speed, size, timings, etc. Generally to get dual channel mode you need 2 sticks from the same manufacturer.

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So, ideally, I would want two 8GB sticks. Would it matter if they where different brands (i.e. Crucial and Kingston) even if the capacity, bus and speed are the same? – topherg Jan 16 '13 at 17:03
It's hard to tell. It could very well work, but not necessarily. Unfortunately the only way to tell for sure is to try it. Even if someone else is able to get dual channel from that combo on their machine doesn't mean it'll work for you - differences in motherboard/memory controller could change the outcome. – Isaac Dontje Lindell Jan 16 '13 at 17:05
ah fair enough, but adding more ram to the system with mismatched capacities, after the memory performance gains, what are the overall costs, or when it comes to these sizes, is it virtually negligible? – topherg Jan 16 '13 at 17:07
Since it's already mismatched, you won't see any decrease. The performance penalty from not having matched RAM is significant, however. It's significant enough that many people would rather have 4GB of matched RAM (two 2GB sticks) than 6GB of unmatched, for example. Note this is for performance. If you need the extra RAM, for example to run lots of big programs simultaneously, quantity is still important. – Isaac Dontje Lindell Jan 16 '13 at 17:10
In that case, instead of wasting money and buying one 8gb stick, ill get 2 8gb sticks (still DDR3-1333 to match my motherboard) and feel the performance gains immensely. Thanks :) – topherg Jan 16 '13 at 17:13

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