Question about replacing my RAM?

Question

I have to replace 2 sticks of ram in my pc. i understand that it has to be the same size. but what i don't under stand is whats stated in my motherboard manual.

"Because of CPU limitation, If you want to install DDR400 memory modules in your system, please install either one double-sided or two single-sided DDR400 memory modules. The DDR400 speed will drop down to DDR333 if you install two double-sided or three single-sided DDR400 memory modules."

i only have three slots for memory and one is filled with 1gig double-sided. what will be my speed if i replace it with 2 more 1 gig double-sided ram sticks? And can i mix and match brand names of ram?

Answer 1

It is basically saying that it will adjust the clock speed you. You will more than likely not know the difference.

DDR-400 200 MHz 5 ns 200 MHz 400 Million 2.6v +/- 0.1v PC-3200 3200 MB/s

DDR-333 166 MHz 6 ns 166 MHz 333 Million 2.5v +/- 0.2v PC-2700 2700 MB/s

Answer 2

Yes you can mix and match brand names of ram,

Answer 3

Go to Crucial.com, will scan system and give you the answers, Never 'mix& match....bad plan.

http://www.crucial.com/uk/?OVRAW=crucial...

Answer 4

u can safely install whutever it takes

the warning is that it reduces bus speed from abt 667 to 333  which u wont notice much in normal applications

Answer 5

RAM must be paired up with an identical stick for the DDR (double data rate) technology to work. 3 RAM slots is a weird number, because their are no even pairs (2 or 4 is more common.) Some manufacturers overcame this limitation and placed 3 slot on the motherboard allowing them to "sort of" activate the DDR technology, but not at full speed. It is more like TDR (triple data rate.) Triple data rate doesn't actually exist, but a few motherboards can "trick" the RAM into working like this.

With 3 1-gig double sided sticks, each stick will run at around 111 MHz. 111x3-333 which is where the 333MHz comes from. If you only had two sticks, each of them would run at 200x2=400MHz. It is simply a physical limitation of the memory to not work at that higher speed when the memory is double sided.

You can mix and match brand names of RAM, but this may further slow the PC. If all three sticks don't match sometimes the motherboard cant support the improved data rate technology, and you will end up having 3 sticks, but they will be written to one at a time which will effectively slow down your system. It is up to you, but with 3 slots I recommend getting 3 identical sticks of memory.

Please note: I am pulling most of this info out of my head. It is from an article I read a long time ago - VERY few motherboards have 3 slots. It is not common practice to place an odd number of slots on the board, and not an "official" standard to activate things like DDR with 3 slots. I told you what I feel to be accurate, but a quick google brought up nothing so I was guessing at part of it. I am pretty PC knowledgeable but I can't guarantee 100% accuracy here.