Load reduction and rank multiplication at 1600MHz ?
1600MHz-rated 16GB RDIMMs (2-rank) are available for Romley – why not LRDIMM/HyperCloud ?
The reason maybe that load reduction and rank multiplication manufacturers are already outperforming the RDIMMs by ONE speed grade.
Offering a 1600MHz version that offers a FURTHER speed grade advantage, while advantageous to end-users, may not offer a greater-units-sold advantage to the manufacturers of load reduction and rank multiplication solutions.
Betamax vs VHS all over again ?
The choice of load reduction and rank multiplication memory – whether HyperCloud or LRDIMMs – may seem superficially like another such “standards battle” – that of Betamax vs. VHS (where the inferior technology won out because of market conditions).
This may superficially seem to be the situation with memory choices – but it is not.
Inphi as a single point of failure
UPDATE: added 06/21/2012: added info on Montage
UPDATE: 07/06/2012 – now a Montage 1333MHz version like Inphi
The top 3 buffer chipset makers are Inphi, IDTI and Texas Instruments.
However Inphi is the only supplier of “iMB” LRDIMM buffer chipsets for Romley.
A combination of lower voltages and higher speeds
DDR3 memory already has trouble achieving the faster speeds at high memory loading.
As you add memory modules on a memory channel (go from 1 DPC to 2 DPC to 3 DPC), the max achievable speeds go down.
At lower voltage (1.35V), the max achievable speeds go down further:
JEDEC and DDR4 finalization
UPDATE: 06/10/2012: this article was slashdotted today
UPDATE: 07/24/2012: added Netlist on JEDEC BOD
While JEDEC has time before they finalize the DDR4 standard to secure relevant IP, they did not exercise similar concern when they finalized the LRDIMM standard.
LRDIMMs were standardized without securing the relevant IP.
Industry estimates of “attach rates”
UPDATE: added 06/19/2012: IDTI comments
UPDATE: added 06/22/2012: analysts on attach rates
UPDATE: added 07/03/2012: Netlist conservative $500M revenue estimate
UPDATE: added 07/03/2012: Netlist conservative $7.5B revenue estimate for 2014
UPDATE: added 07/04/2012: isuppli.com on LRDIMM market
For DDR3, load reduction is essential at:
Market for load reduction
UPDATE: added 06/06/2012: info on LRDIMM market
In summary, if you follow the constraints outlined in the other articles here:
LRDIMMs validated by JEDEC without licensing relevant IP
LRDIMMs are based on a single-sourced “iMB” buffer chipset from Inphi (more on that below).
Patent and reexamination docs
This will be a simple guide to following the progress of patent and patent reexams at the USPTO.