I am intending upgrading the memory in my computer from 4 to 12Gb. Currently I have CSR-4G1609 Corsair XMS3 4GB (2x2GB) DDR3 PC3-12800C9 1600MHz Dual Channel Kit Is it better to stick to the same make of memory or are brands compatible?
Understand you MUST be running a 64-bit operating system to take advantage of that extra RAM. Today's RAM manufacturing technologies ensure (as much as possible) all RAM coming off the assembly lines tightly falls within required tolerance specifications for that RAM type and model. Plus, today's memory controllers are much more capable at facilitating multiple RAM sticks working together. So I agree with the above, compatibility between brands is not the issue it used to be. Note in the old days, dual channel kits contained a pair of RAM sticks that were tested and paired because their test results matched. Today, because of the advanced manufacturing technologies, dual kits are just two sticks of the same model packaged together for convenience. But the RAM still must be compatible with the motherboard. So you MUST ensure the specs of the RAM matches the specs the motherboard supports. Check the QVL (qualified vendor list) of supported RAM at the motherboard/computer maker's website.
Thanks - yes running Win 8/64. Just wondering that if you are using 32 bit programs obviously they still work within the memory capacity, but does the data they produce make use of the extra ram?
No. The data programs produce are just files. 32-bit and 64-bit deal with the "environment" the programs run in, and not the data they produce. For example, a document file created by 64-bit Word is exactly the same as the same document file created by 32-bit Word.
Just to clarify - 32 bit programs can make use of the extra space for data which can be held in memory rather than on disk?
No. It is the operating system that manages your RAM and how your running programs use it. Don't look at it as "extra space". Look at it as more lanes for the data to use. For example - there are 100 people with 100 full shopping carts waiting to check out at Walmart. The same amount of "work" is accomplished if there are 32 checkout lanes open, or if there are 64 lanes open. But obviously, that same amount of work will get done quicker with more lanes open.
Au contraire Bill. I now have 8GB RAM, and for my OS use a 32-bit Linux Ubuntu 12.04.2 LTS USB flash to boot up and use all of it. The free command yields: Mem: 8155712 2123152 6032560 0 163656 1038560 -/+ buffers/cache: 920936 7234776 Swap: 1799236 0 1799236 The difference is that my MB/CPU/OS supports PAE (Physical Adress Extension). -- Tom
Linux and Windows Server 2003 Enterprise with PAE don't count. 32 bit processes on a 64 bit system with 12GB of RAM can still only use 2GB of memory maximum (per app, not referring to the 4GB maximum addressable). 64 bits and more RAM does not overcome this limitation. Not even wanting to get into the /3GB switch, which most software cannot benefit from unless it was compiled to take advantage of, which most has not been.
