Questions about RAM

[Shadowfire_Omega]

Ok, the first question is about Dual-Channel RAM. I have confirmed that my Dell Inspiron N5040 supports Dual-Channel DDR3 SDRAM W/memory speeds of 1333, and I know that I need Identical DDR3 SDRAM sticks to utilize this feature, but therein lies my question, where exactly do the sticks need to be identical? do they need to be made by the same manufacturer? or do they just need to be the same size?

Now my second question, arising from situation A-sticks just need to be the same size and i buy one new stick, and even from situation B-need to be identical so i buy 2 more and put my old one into my mom's laptop

I came across this odd statement on the dell site about this stick of ram:When mixed, the memory will perform at the lowest speed populated or the highest speed allowed by the system.
It is worded oddly, so let me see if i get this correctly, by lowest speed populated, it means if I put in 6gb of ram as 2 cards at 2gb and 4gb, it will run at 6gb, as the full population of ram, or will it run at 2gb at the lowest speed of one of the populated ram slots? and what if it was 2 4gb sticks, would it be considered mixed?

 

[MindoverMaster]

Sticks do not to be the same size to be dual channel. Dual Channel is an architecture built into the memory controller, not into the RAM chips itself.

When mixed, the memory will perform at the lowest speed populated or the highest speed allowed by the system

That statement has nothing to do with the amount of RAM. It is to the speed, as 1333 or 1600. This means that if you used a 1600 stick with a 1333 stick, it will clock down to the 1333.

 

[carnageX]

For identical RAM, just make sure their clock speeds are the same, and their timings / voltages are the same / similar.

It's talking about the speeds of the RAM, not the sizes.

Say you have 2 sticks of some RAM modules A, at 1600, and you have 2 sticks of some RAM modules B, at 1066.

If you mix both sets A and B in, all of the RAM will run at the 1066 speed, rather than some at 1600 and some at 1066.

This, is of course, unless your motherboard doesn't support that high of speed (say your board only supports 800... then all 4 sticks of RAM will run at 800).

Make sense?

Edit: ninja'd by MoM.

 

[Shadowfire_Omega]

Cool, thanks guys