which DIMM slots for dual-channel ?

dcb91

New Member
when i first put my RAM in, i used the DIMM 1 & DIMM 2 and it came up as single channel. I now have the RAM in DIMM slots 1 & 3 and it comes up as dual channel. why is this? shouldn't you be able to pair the RAM sticks side by side (DIMM 1 & 2) for dual channel?
 
No, they have to be in the slots that are wired to the second channel. Usually this is the 1/3 and 2/4 slots.
 
The board's manual is always the first place to look since different board also label the sloys differently. On one board you will see slots A1 and B1 as the first for each channel. The next board will see Slot #0 and Slot #2 or some other combination as T_O_O just mentioned. On some older boards filling all slots forced the single channel mode. That's why you go by the manual first.
 
Actually the board isn't set in dual channel mode when two dimms are on one channel. The first dimm slot on most boards is usually required to have something in it. On a four slot board you then skip over the second on the first channel for the first on the second. The 2 and 4 slots on some boards will be a light blue, green, or almost a pinkish color to separate those from the typical black colored second slot. The reason for seeing 2 and 4 is the way the board is traced for circuit paths mainly.
 
Like mentioned before most newer boards see the two colored slots identifying which is the primary and secondary slot for each channel. The manual's pages on installing memory on a particular board is where to look for this. That's the "no can go wrong there" approach. You simply follow the manufacturer's instructions.
 
If it says Dual-channel at post you don't need to change anything. If you're still unsure just download CPUz and have a look.
 
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You don't have to download anything to find out. When first installing the memory do you simply swap it into the slots or... Read the manual?!
 
my mobo has four dimm slots, dimm 1 & 3 are blue, dimm 2 & 4 are black, i just put my ram in the matching colors (1 and 3) and now it says dual channel. i first installed them in 1 & 2 but single channel came up...
 
my mobo has four dimm slots, dimm 1 & 3 are blue, dimm 2 & 4 are black, i just put my ram in the matching colors (1 and 3) and now it says dual channel. i first installed them in 1 & 2 but single channel came up...

The color difference there shows black as the second slot on the same channel. The matching blue slots are the first slot on each channel there. There are some boards that will see that reversed due to how the board is layed out in design. For that you have to follow the traceways to see why.
 
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