Can non matched memory run as a matched pair?

[HeXploiT]

Anyone ever get a non matched pair to run in dual channel mode?
What if the chips are very similar?
What is it that tells the computer a pair is matched?

 

[n7]

Lots of time i've seen non-pairs work in dual channel.

I'd love to hear from someone who really knows the technical details of what dictates whether dual channel can function or not though.

+1 to that question indeed.

 

[ionoxx]

To run dual channel with unmatched dimms you have to match the density and banks, as far as I know.

Symmetric Dual Channel example.

1x 1GB Single sided + 1x 1GB Single sided works
1x 1GB Double sided + 1x 1GB Double sided works
1x 1GB Single sided + 1x 1GB Double sided will NOT work

Some boards, check manual can do Assymetric

1x 1GB Double sided + 2x 512MB Single sided works

If you use different speeds, they will both downclock to the slower of the two speeds.
If you have different timings... they will both use the slower timmings.

 

[Yellowbeard]

Years ago, I ran a single 512mb PC2700 Samsung based module with a PC3200 Winbond based module in dual channel on a P4C800 E-D. Most of this will be determined by your MOBO+bios and how the memory controller reacts to 2 different modules. Matched pairs are recommended by manufacturers so that they can guarantee compatibility. But, if you have memory on hand that is not matched, you can certainly test it.