Why have four when running a base three?

[jimmyj68]

My cursory understanding of Nehalem processors is that they control memory on board the CPU in a three channel fashion i.e. three ram sticks - same size, voltage etc. It's easy to understand a board with six ram slots or three ram slots ---- what's up with a board with four ram slots????? How do you evenly divide a factor of three in four??? If one slot is to be always empty - why put it there?

 

[PCTC2]

It will still run in triple channel mode. Two sticks will run on their own channels, but the remaining two sticks will be in a flex-channel, both running on the same channel, sharing the bandwidth. It's for those who bought dual channel kits for older chipsets.

 

[jimmyj68]

Thanks for the reply PCTC2 - I got into a wrestling match with my wife's computer and didn't get back to you earlier - it's all explained in general hardware.

I know what you told me, but I don't understand. How would you arrange 6 gig of ram in four slots???? Unless you leave the four slot empty - are the boards designed to be OK with that? They do usually have the 4th slot a different color.

 

[PCTC2]

Yes. They are designed to have the odd colored slot empty. i7 is triple-channel and prefers sticks in multiples of 3. If you run 6GB, it is 100% okay to leave the 4th slot empty. i7 brings a new game to the table. Everyone is used to double channel with multiples of 2.

 

[jimmyj68]

ok so it looks like the board makers with 4 slots are just saving a few bucks on making the board. Thanks - now if I could only find a board that didn't have 3 pcie 16 slots