At Computex 2023, we saw two next-generation server technologies from Intel. First, we saw what appears to be an Intel Granite Rapids motherboard. Second, we saw a MR-DIMM which is pronounced “Mister DIMM” and that placard says it is for Granite Rapids.
Intel Granite Rapids Motherboard?
Just for some context, Intel is going to rapidly increase the pace of its Xeon generations after its 4th Gen Intel Xeon Scalable Sapphire Rapids launch earlier in 2023. Instead of one generation per 18 months or so, Intel is looking at three generations in under two years. The next generation is Emerald Rapids slated to slot into the same platforms and then Granite Rapids.
That leads us to this motherboard with covered sockets on the Computex show floor. Normally, sockets that have been launched for 5-6 months are not covered on show floors, and only next-gen sockets are covered. This motherboard looks like an early attempt at an OCP DC-MHS motherboard which might be notable itself, but there is something missing.
There is an Intel FPGA near the OCP NIC 3.0 and DC-SCM slots on the top of the motherboard above, but there is no PCH onboard. The sockets are covered and look a bit like SPR sockets from afar, but this does not appear to be a 4th Gen/ 5th Gen Intel platform since it is missing that detail. Intel is modernizing its platform design with Granite Rapids/ Sierra Forrest so that is the first generation we expect to be PCH-less meaning that, despite the covered sockets, that is likely what we are looking at.
MR-DIMM versus MCR-DIMM
Part of how Intel and AMD are planning to get more memory bandwidth in the next-generation of servers is to use not just DDR5 memory, but also to use multiplexing on DIMM modules. Thus far, Intel has discussed its plans to use MCR-DIMMs at Intel DCAI 2023 Update New Technology and Updated Xeon Roadmap. Coincidentailly, we had just covered What is a MCR DIMM or Multiplexer Combined Ranks DIMM before that announcement.
The MCR-DIMMs allow for much higher transfer speeds. Even with fewer DIMM channels, having the new DIMMs will allow for much greater bandwidth per DIMM.
On the AMD side, rumor has it that the company is working on MR-DIMM technology along with moving eventually to 16 channel memory in future platforms, up from 12 channel memory with Genoa/ Genoa-X/ Bergamo.
In the ADATA booth, we saw a MR-DIMM. If you are wondering, yes, people in the industry even by JEDEC standards folks call these “Mister DIMM”. We knew that AMD had an eye on MR-DIMM technology, but then the placard below the DIMM said Granite Rapids.
Going through to the QR code site says that it supports Intel SPR platforms. We know this type of memory is coming, but there is probably a question on which standard will be used in the industry that will be answered in short order. Seeing Intel demo MCR-DIMMs then ADATA show a MR-DIMM for the same platform seems strange.
Final Words
Part of the fun of Computex is that beyond booths, there is a lot we get to see. Still, there are always technologies that are shown on the show floor that give us pause. These are a few good examples from this year’s show.
Can’t wait for JEDEC to standardize the Mister DIMM mascot.
Important question regarding MR/MCR DIMM: Are they going to demand a big premium like they do with LR-DIMMs? Will we have to pay not just to get more capacity (like we do now) but also for higher speed?
The data buffer and clock/address chips are def more advanced than for LR.
I guess I’m gonna sound a bit stupid, but what’s the difference between MCR and MR in regards to these new memory modules? The author gives us Multiplexer Combined Ranks for MCR, but nothing at all for MR. Can somebody explain? Thanks.