Samsung announced it is mass producing high-density, low-power DDR4 RDIMMS using advanced 3D technology that layers multiple chips vertically to reduce power consumption and improve performance. They'll be expensive, so who needs them?
...64 gigabyte (GB), double data rate-4 (DDR4), registered dual Inline memory modules (RDIMMs) that use three dimensional (3D) “through silicon via” (TSV) package technology.
Upacking the jargon
Registered DIMMs have a buffer between the DRAM memory and the server memory controller. The register reduces the electrical load on the controller, enabling a system to support memory than otherwise.
For example, the new Mac Pro can support 64GB of DRAM with RDIMMs vs 32GB with unregistered UDIMMs.
3D technology, in this case, means stacking up 4 memory chips on top of each other to get greater density in the same square mm.
Through silicon vias are simply holes in the memory chips through which conductors connect the chips. Samsung describes their process:
To build a 3D TSV DRAM package, the DDR4 dies are ground down as thin as a few dozen micrometers, then pierced to contain hundreds of fine holes... As a result, the new 64GB TSV module performs twice as fast as a 64GB module that uses wire bonding packaging, while consuming approximately half the power.
The Storage Bits take
If the power savings and performance claims pan out these DIMMs will be popular in large memory applications — VM servers, in-memory databases — where DRAM power is a significant cost and more performance is always welcome. 64GB RDIMMs have been shipping for a while, so these won't double server memory capacity, but Samsung is contiuing to push the envelope.
Given the cost of the extra processing required though, only well-heeled enthusiasts will buy them for personal machines. But maybe in a few years...
Comments welcome, as always. Where would you put high-performance, low-power DRAM?