Micron Ships World's Most Advanced DRAM Technology With 1-Beta Node

[Valantar]

The non-binary DDR5 is because DDR5 is two 32 bit RAM modules together (hence the quad-channel reading in CPU-Z)

But DDR4 also has no problems running two different sized kits in dual channel.

Also, DDR5 sub-channels are AFAIK teamed together on a low enough level that describing them as sub-channels is more accurate than treating them as separate channels.

2x 16+32 is fine

If so, then why would a GDDR controller not be fine with a similar "1.5x power of two" amount of memory per channel? Even on DDR5 it's not like that would split into 16GB on one sub-channel and 32 on the other - both DIMMs would be split evenly.

 

[Wirko]

Because the primary OS does that mapping

Yes but the guest OS is still able to adapt to any size.

The non-binary DDR5 is because DDR5 is two 32 bit RAM modules together (hence the quad-channel reading in CPU-Z)

That means they can mix 16+32 and dual/quad channel still works as long as you have binary numbers (2/4/8) of each stick

2x 16+32 is fine

1x 16+32 and 1x 32+64 would not work in dual channel

Intel says that it works:

Asus says that it works on AMD boards too:

The exact same text is found in the manual for my 15-year-old Socket 775 board with DDR2 and DDR3 slots, the Asus P5KC.

Actually the IMC is smart enough to make part of the memory dual-channel and the other part single-channel if you throw weird combinations into the slots. Intel calls that capability "flex mode", it's at the bottom of the Intel's document I linked.

 

[Mussels]

But DDR4 also has no problems running two different sized kits in dual channel.

Yes, DDR5 just has four channels to work with - comes out exactly the same where each pair of memory has to be the same size, and a binary amount.



Just because you can add 3x512MB to get 1.5GB doesnt mean you can get a 1.5GB stick of RAM and have it work

 

[Valantar]

Yes, DDR5 just has four channels to work with - comes out exactly the same where each pair of memory has to be the same size, and a binary amount.



Just because you can add 3x512MB to get 1.5GB doesnt mean you can get a 1.5GB stick of RAM and have it work

... But it was just posted that there are 48GB DDR5 DIMMs in production. That's equivalent to a 1.5GB DIMM. Also, you're talking as if mismatched dual channel setups are distributed unequally across channels - they don't need to be. A single DDR4 channel can handle 4+8GB or 8+16GB just fine.