02:55PM EDT - This year at Hot Chips, Intel is presenting the latest updates to its Optane PCDMM strategy.

02:57PM EDT - Intel Optane DC Persistent Memory

02:57PM EDT - The memory-storage gap slide where Optane goes

02:57PM EDT - Oh wow, they've made the same mistake again. This machine doesn't have the Intel font so everything looks off

02:59PM EDT - SSD like capacity to DRAM

03:00PM EDT - We've heard the architecture of Optane before - crosspoint structure, non-voatile, bit-alterable, up to 512GB in first generation

03:00PM EDT - Designed to scale in layers

03:02PM EDT - DRAM module architecture

03:03PM EDT - Sorry the picture is bad, click through for full resolution

03:03PM EDT - Onboard Optane controller with firmware and integrated PMIC

03:04PM EDT - Built in ECC

03:05PM EDT - Two modes, Storage mode or Memory mode

03:05PM EDT - Asyncronous DRAM refresh - power fail protected failure

03:07PM EDT - In memory mode, DRAM is used as a write-back cache and treated like a near memory. Optane is far memory.

03:07PM EDT - Software/App Direct Mode shows the Optane as a storage

03:08PM EDT - Support for DMA and RDMA, cache coherent, byte-addressable, in-place persistance

03:08PM EDT - Now Performance

03:08PM EDT - Latency vs SSD

03:09PM EDT - 100 microseconds for normal SSD vs Optane SSD (10 microseconds) vs Optane DCPMM (0.2 microseconds)

03:09PM EDT - 180 microseconds vs 70 on DRAM

03:10PM EDT - This is a R/W mix of traffic

03:10PM EDT - Read idle latency peaks at 340ns

03:11PM EDT - Memory Mode transaction flow between CPU and DCPMM vs standard

03:11PM EDT - DRAM cache hit vs cache miss

03:12PM EDT - transparent to software

03:13PM EDT - Bandwidth is near DRAM, as you miss there is some degredation

03:14PM EDT - A lot of workloads doesn't require full bandwidth all the time

03:14PM EDT - Up to 6TB in dual socket

03:15PM EDT - Enables consolidation with larger memory per server

03:15PM EDT - Increases virtualized capacity based on memory

03:16PM EDT - Redis examples show under 1ms SLA quality even with max VMs in 6TB setup

03:17PM EDT - App Direct Mode

03:18PM EDT - To take full advantage App Direct, requires software adjustments

03:19PM EDT - In Redis and enabling logging, Moving Value section to App Direct Optane reduces DRAM use and optimizes logging by 2.27x

03:21PM EDT - Q&A time

03:24PM EDT - Q: Spare capacity? There is spare capacity and wear levelling across all chips

03:25PM EDT - Q: Can you bring the Optane on package with CPU? A: It's possible, but not today

03:28PM EDT - Q: Why is 64B a slower latency than 256B? A: Our buffers are based on 256B, so on 64B reads you get buffering which increases latency. If you run at 256B, you get additional benefits from our buffer sizes

03:28PM EDT - That's a wrap. Time for lunch. The next live blog is on MLperf at 3:15pm PT.

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21 Comments

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  • azfacea - Monday, August 19, 2019 - link

    z-ssd is not any where close to 100 microsecond. they've also revised down density and wear and tear claims big time.

    even then walking it back 2x after 4 years is hardly impressive
    Reply
  • Phynaz - Monday, August 19, 2019 - link

    You write a lot, yet provide no supporting evidence. Reply
  • azfacea - Monday, August 19, 2019 - link

    "You write a lot" yea if you don't like that fuck off. you are in the wrong place not me.

    might be too hard to comprehend for you but its called online comments where ppl "commnet".
    Reply
  • Korguz - Monday, August 19, 2019 - link

    azfacea, just ignore Phynaz, he doesn't provide proof of anything he says HIMSELF, and then just insult and call people names, when he gets call out on it, or gets asked for proof Reply
  • name99 - Wednesday, August 21, 2019 - link

    Samsung says Z-SSD is 20usec, and no-one has disagreed with that:
    https://www.samsung.com/semiconductor/ssd/z-ssd/
    Reply
  • johannesburgel - Monday, August 19, 2019 - link

    I must have sat through about ten Intel NDA briefings in the last four years and 3D Xpoint/Optane was always the most boring topic. A solution in search for the right problem. By now I just tune out when it comes up. And I also don't know anybody else who would care. Reply
  • remosito - Wednesday, August 21, 2019 - link

    DB Server guy here. Care a lot. Reply
  • name99 - Wednesday, August 21, 2019 - link

    For what purpose?
    Larger transient address space (so basically like a very fast VM)?
    Or persistence? And if persistence, to bypass file abstraction latency? Or something else? Ie what’s the win over Optane nvme?
    Reply
  • name99 - Wednesday, August 21, 2019 - link

    Intel thinks Optane SSD is slower than flash? (2nd slide)
    WTF? The marketing machine really is off the rails now...
    Reply
  • name99 - Wednesday, August 21, 2019 - link

    Oops, my bad
    It’s not Optane that’s worse than generic SSD, it’s just Intel 3D NAND.
    OK, then...
    Reply

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