Overclockers love Samsung's B-Die memory, but the company is unceremoniously killing it off. According to the consumer DIMM section of Samsung’s latest Product Guide, B-Die memory "dies," M-Die matures, A-Die ascends, and 32GB UDIMMs really are available in Q2 2019.

We’ve yet to see whether A-die chips will have the overclocking flexibility to match or exceed that of the current B-Die products that have become the memory of choice for overclockers on Intel and AMD platforms alike.

The new A-Die offers the advantage of higher available chip density, particularly to module assemblers/programmers (i.e., the companies we’re accustomed to supplying our XMP-rated DIMMs). The 16Gb (sixteen gigabit) M-Die chips that were supposed to have brought us 32GB consumer DIMMs a year ago appear to have been reserved for Samsung’s own-brand modules, and the best guess from our suppliers has been that the server sector has drawn that supply dry.

4.7 260Pin DDR4 Non ECC UDIMM

[Table9]260 Pin DDR4 Non ECC UDIMM

Density PartNumber Composition Comp.Version InternalBanks Rank Height Avail. 2GB M378A5644EB0 256Mx16*4pcs 4Gb E-die 8 1 30mm EOL '181Q 4GB M378A5244CB0 256Mx16*4pcs 8Gb C-die 8 1 30mm MP 4GB M378A5244BB0 256Mx16*4pcs 8Gb B-die 8 1 30mm EOL '191Q 4GB M378A5244BB0 256Mx16*4pcs 8Gb B-die 8 1 30mm EOL '191Q 4GB M378A5143EB2 512Mx8*8pcs 4Gb E-die 16 1 30mm EOL '182Q 8GB M378A1K43DB2 1Gx8*8pcs 8Gb D-die 16 1 30mm CS '182Q 8GB M378A1K43CB2 1Gx8*8pcs 8Gb C-die 16 1 30mm MP 8GB M378A1K43CB2 1Gx8*8pcs 8Gb C-die 16 1 30mm MP 8GB M378A1K43BB2 1Gx8*8pcs 8Gb B-die 16 1 30mm EOL '191Q 8GB M378A1K43BB2 1Gx8*8pcs 8Gb B-die 16 1 30mm EOL '191Q 8GB M378A1G43EB1 512Mx8*16pcs 4Gb E-die 16 2 30mm EOL '182Q 16GB M378A2K43DB1 1Gx8*16pcs 8Gb D-die 16 2 30mm CS '182Q 16GB M378A2K43CB1 1Gx8*16pcs 8Gb C-die 16 2 30mm MP 16GB M378A2K43CB1 1Gx8*16pcs 8Gb C-die 16 2 30mm MP 16GB M378A2K43BB1 1Gx8*16pcs 8Gb B-die 16 2 30mm EOL '191Q 16GB M378A2K43BB1 1Gx8*16pcs 8Gb B-die 16 2 30mm EOL '191Q 32GB M378A4G43MB1 2Gx8*16pcs 16Gb M-die 16 2 30mm CS '182Q 32GB M378A4G43AB1 2Gx8*16pcs 16Gb A-die 16 2 30mm CS '191Q

SuperBiiz lists part number M378A4G43MB1 as a current, out of stock product, and with no customer reviews…ever. The additional A-Die part number M378A4G43AB1 could potentially increase supply, but only if that increased supply can finally meet the company’s higher-market obligations.