What is "Double Row" DDR?

[BCinSC]

Can't seem to get info on difference.

 

[Fike]

RAM sticks with memory chips on both sides. some motherboards don't like them or they need to step down to slower speeds to handle them

 

[DaveSimmons]

Or the motherboard memory controller can only control so many of them, for example a max of 2 DR / double-sided sticks vs. 3-4 single sided.

 

[BCinSC]

Not Double Sided. Double Row. Found a blurb on Kingston's site:
"KVR "D" parts are double banked (X8) for AMD-based systems only. These parts will not support Intel-based chipkill technology."

 

[Mark R]

There may be some confusion over what exactly is meant.

'Dual row' is an unoffical term (usually called 'stacked') which means that there is a second row of chips installed underneath the chips that you can actually see.

'Dual bank' is probably what you mean. This means a DIMM with the chips connected so that it appears to the motherboard as 2 seperate DIMMs each of half the capacity (Some motherboards have limits as to how much RAM they can actually access on one DIMM). 'Dual bank' is also sometimes called 'double sided'. Note that 'dual bank' or 'double sided' doesn't actually have any relation to whether there are chips on both sides of the circuit board.

Chipkill is a more advanced type of ECC used on Opteron CPUs and some Xeons which can keep your system runnning flawlessly even if a whole chip on a DIMM fails. Normal ECC can work with any type of DIMM as long as it has 9 chips for every 8 that a non-ECC would have. Chipkill ECC requires 18 chips per 'side' of a DIMM.

I've noticed that there are quite a lot of typos and mistakes on Kingston's site. If you can't rely on the manufacturer to give good information...

 

[BCinSC]

Then you'll laugh at Crucial's explanation:
"A module that has chips on both sides of the printed circuit board is said to be double-sided, and a module that only has chips on one side of the printed circuit board is single-sided. In most cases, double- and single-sided modules can be used interchangeably. In fact, if you have two 64MB modules, one may have chips on one side, while the other has chips on both sides, and the two can be used together in most systems. If your system requires only single-sided or only double-sided modules, those requirements are built into our Memory Selector."

 

[BCinSC]

BTW, your photos are AMAZING!

 

[Mark R]

Well, I suppose that just demonstrates why there's so much confusion.

A lot of people refer to 'single-sided' and 'double-sided' as whether there are chips on both sides of the circuit board. A perfectly reasonable thing to do.

However, you see a lot of hardware specifications for motherboards e.g only 2 'double-sided' DIMMs are supported - here they mean the electrical connection. Perhaps it would be more correct to call this 'dual bank' rather than 'double sided'.

This is probably made worse because of difficulties with translation, as English may not be the first language for many comuter designers.