1x8 RAM re-installation MSI GP60 2PE LEOPARD-472

[harrilynch]

I am trying to upgrade the current RAM of my msi gp60 laptop from its current 1x8 to 2x8 by buying another 8gb stick. should I buy the exact same stick that is in there now (msi16d3ls1kbg/8g)? Or can I just get another similar stick? Also is it possible to add 4gb to have 12 total with 1x8 and 1x4? Basically, would I be able to upgrade and keep my origina stick or do I need to go out and buy a whole other set instead of just half.

 

[thx1138v2]

You'll be better off buying a "kit", i.e two sticks of RAM that were tested together by the manufacturer. Mixing RAM, even from the same manufacturer with same part number, can have problems working together due to manufacturing process variations. Two modules from different manufacturers are highly unlikely to work together and if they work at all they will probably work at a slower speed and as "interleaved memory, meaning you give up the benefit of the the dual channel memory bus.

Each module has a 64bit wide data path. With different modules that do end up working together or with a 1X8 and a 1X4 used, that data path will be treated as one 64 bit wide bus.

With the matched pair of a kit working together in dual channel mode the data bus will effectively be 128 bits wide because they can read/written at the same time. So the memory will appear to be twice as fast because it only takes half as many read/write cycles to read/write the same amount of data.

That's assuming you have a dual channel motherboard, which you do. If you had a triple or quad channel motherboard the effective bus size would grow to 192 and 256 bits wide, respectively.