Wednesday, July 18, 2018

Optane DIMMs: What is it, how fast, how much?



You got questions? We got Answers. A while back, Intel announced more about Optane DIMMS for data center. Vague information on when customers can get it ("select customers some time in 2018, volume sometime in 2019"). No information on speed or endurance. Densities are 128GB-512GB DIMMS. Fortunately we at MKW Ventures have models for what it is and how it works and how much it costs. Updates below with lots of additional information available.

While you can't buy it today and we don't know when you can buy it, Intel committed that you can test it out in the cloud sometime soon.



Questions from My January Blog and some answers based on a our model
  • What is in a Optane DIMM? its up to 10 XPoint packages+ smaller controller, power unit and buffers. It has 20% overprovisioning on the DIMM plus about 10% overprovisioning on the chip itself
  • How fast will an Optane DIMM be? Intel says it works at DDR4 speed we assume this is 2133-2666+ MT/S. Latency is between DRAM and NAND (we can discuss the actual latency)
  • What will the price be? Servers with Optane DIMMS will be very expensive. Standard case will be 192GB of RDRAM plus 1TB of Optane DIMMS. In this case, the price just for the DRAM and Optane will be >$7500 
  • What is the optimal DRAM DIMM to Optane DIMM ratio in a server configuration? Intel initial configuration is 1:5. Still need lots of DRAM as >90% of operations access the DRAM, not the Optane.
  • How many applications will have been optimized for persistent memory by end of 2018? lots are in development now. But Optane will be in less than 10% of servers being sold in December 2018
More ...new ... questions from May 30th presentation

  • What is endurance of Optane DIMM: Intel said they will last as long as system. We have modeled actual cycles possible and how it is managed to meet the criteria Intel committed to
  • Is it really DDR4 compatible: on size and electrical and thermal.... the answer is "sort of". We have the details but it depends on the motherboard.
  • Why do I still need DRAM in large amount on my server? correct ratio of Optane to DRAM is 5:1 to 10:1. We have models why this is
Intel won't provide the info on Availability, latency, cost, price, % of systems that will have optane DIMMs. Fortunately we will provide that to you and we can discuss in person at Flash Memory Summit in August

Mark Webb

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