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Case in point: > chips will support up to 3.84 TB of memory per socket ... due to combining 512 GB Optane DIMMs and 128GB DDR4 DIMMs > ... > in a 6 x Optane

Case in point: > chips will support up to 3.84 TB of memory per socket ... due to combining 512 GB Optane DIMMs and 128GB DDR4 DIMMs > ... > in a 6 x Optane and 6 x DDR4 configuration, they will provide 3072 GB of 3D XPoint memory and 768 GB of DDR4 RAM for a total of 3.84 TB of memory Optane DIMMs don't really have the performance characteristics of traditional DRAM. It sounds like the real capacity per socket is 12 x 128GB = 1.53 GB, which is the same capacity as the previous generation. That being said, I'm optimistic about Optane DIMMs - it seems like an interesting performance point in between DRAM and SSDs.

evfanknitram 8y ago
Tiny correction: Should be 1.53 TB, not 1.53 GB
- akmittal 8y ago
  Certainly not tiny, off by 32 bit
  - MertsA 8y ago
    Tiny correction: Should be 10 bits not 32 bits.
  - evfanknitram 8y ago
    I meant tiny as in maybe not even worth pointing out since people will understand it anyway.
  - detaro 8y ago
    only 3 bit diff between the strings
- ScottBurson 8y ago
  Even tinier correction: it's exactly 1.5 TB (1536/1024).
nottorp 8y ago
Yeah, marketing lies. Go AMD go!
- gameswithgo 8y ago
  AMD is guilty of it as well. "AVX2" -> not really! But yes I do wish them well. Make the avx support real AMD!
  - cmsimike 8y ago
    As far as I know, Ryzen has avx-256, its four 128bit units can join as two 256 bit ones without any penalty. What makes this not real AVX? Because there is not one dedicated 256-bit unit?
    - gameswithgo 8y ago
      > without any penalty. My understanding is that without any penalty was not true, but it is possible the new gen cpus have changed that, I have not firsthand benchmarked it.
    - ajross 8y ago
      > without any penalty Except literally running at half capacity. That doesn't qualify as a "penalty" to you? The point was that AMD advertised support for AVX in a context where you'd expect it to be performance-comparable, and what they shipped was "support" for AVX in the sense that the code wouldn't crash, but wouldn't provide any performance benefit over SSE either.
      - gameswithgo 8y ago
        oh, they are twisting words with the marketing about "no penalty" pretty bad!
      - hajile 8y ago
        https://en.wikichip.org/wiki/intel/frequency_behavior https://en.wikichip.org/wiki/intel/frequency_behavior Intel reduces clockspeeds when running AVX2 and drastically decreases clockspeeds when running AVX512. AMD's slightly smaller unit doesn't need to slow down, so the actual performance difference is smaller than it would appear. Changing frequency takes time. Also, if you are putting through an AVX instruction and a few integer instructions at the same time, the integer instructions will downclock the whole time the AVX pipeline is in use (plus the time before/and after while the clockspeed is being adjusted) decreasing performance for more than just the AVX. There are a couple articles written on the topic. Here's one. https://blog.cloudflare.com/on-the-dangers-of-intels-frequency-scaling/ https://blog.cloudflare.com/on-the-dangers-of-intels-frequen... https://software.intel.com/en-us/forums/intel-isa-extensions/topic/520653 https://software.intel.com/en-us/forums/intel-isa-extensions...
throwaway2048 8y ago
Intel keep positioning optane as "close to dram" preformance (especially with misleading marketing nonsense like this), it does have some advantages over flash, mostly related to random access times, but its nowhere near the orders of magnitude more preformant that something would require to fill the preformance point between DRAM and SSDs. Optane is almost entirely hype, with no substance.
- mtgx 8y ago
  > Optane is almost entirely hype, with no substance. As it has been from the very first announcement. Intel is being very misleading marketing Xpoint as "memory". It's not even saying it's "close to memory" now. They're literally calling Xpoint memory (as in the same meaning we use for RAM). Considering Xpoint has much lower performance than RAM, I'm starting to believe that maybe the FTC should intervene over "false advertising". It's just too bad the U.S. doesn't have as strong laws as Europe does for false advertising.
- imtringued 8y ago
  I don't see how a first generation product with similar performance and superior latency to a mature technology (nand) that took decades to develop has no substance. The second generation of Optane is coming out this year and it's going to be an order of magnitude better. It's just a matter of time until nand is obsolete.
  - llampx 8y ago
    If Optane is Intel-only, it is not going to replace NAND.
- ChuckMcM 8y ago
  You and mtgx both mention Optane performance is "not even close to dram." I'm interested in if you have found anyone who has benchmarked the DIMM version with respect to actual DRAM. I see several sites that have benchmarked the Nvme version but this has additional hoops that the DIMM version would not have to jump through and so I've been on the lookout from Anandtech or another reputable source for actual numbers.
djsumdog 8y ago
But what market are they even trying to hit here? DDR4 prices are insane, but home consumers don't run large NUMA systems. Data center admins are going to be able to get the capitol for real DDR4 over Optane. They'd need to be ordering a lot of servers before the price point becomes significant enough that they'd order an Optane configuration and decide to benchmark them. I'd be curious about the real benchmarking at that point. It there a performance boost to simply have more memory, even if some of it is Optane, or is it better to have a lower capacity without the Optane sticks? I have a feeling this will vary heavily by application too.
- leetcrew 8y ago
  > It there a performance boost to simply have more memory, even if some of it is Optane, or is it better to have a lower capacity without the Optane sticks? I would imagine it depends entirely on whether your working set fits in main memory already. if yes, you're not gonna get much speedup from more memory. but if you have to keep swapping from a traditional SSD, it's gonna be hard for faster main memory to make up for that.
- naveen99 8y ago
  I thought the real advantage of Optane was bypassing the pcie bus, with much larger bandwidth of dimm: 80GB/s instead of 12GB/s
  - tgtweak 8y ago
    DDR4 dimm read throughput is about 20GB/s per dimm. PCIe 3.1 x4 is 16GB/s. I feel very comfortable claiming that these optane dimms will not reach 20GB/s of sustained performance. The advantage here being latency (and thus single queue throughput)
    - naveen99 8y ago
      But pcie bus is shared with other cards. So 8 dimms is 8x faster than 8 pcie cards.
eloff 8y ago
Well at least it can address 3.84 TB of RAM (maybe more, because that's not a multiple of a power of two.) I suppose if you could get 256GB DDR4 DIMMs you'd have 12*256 = 3072 = 3TB of RAM. Yuu'd have to give the RAM cartel your first-born to pay for it, but that would be some machine!

evfanknitram 8y ago

Tiny correction: Should be 1.53 TB, not 1.53 GB

akmittal 8y ago
Certainly not tiny, off by 32 bit
- MertsA 8y ago
  Tiny correction: Should be 10 bits not 32 bits.
- evfanknitram 8y ago
  I meant tiny as in maybe not even worth pointing out since people will understand it anyway.
- detaro 8y ago
  only 3 bit diff between the strings
ScottBurson 8y ago
Even tinier correction: it's exactly 1.5 TB (1536/1024).

nottorp 8y ago

Yeah, marketing lies. Go AMD go!

gameswithgo 8y ago
AMD is guilty of it as well. "AVX2" -> not really! But yes I do wish them well. Make the avx support real AMD!
- cmsimike 8y ago
  As far as I know, Ryzen has avx-256, its four 128bit units can join as two 256 bit ones without any penalty. What makes this not real AVX? Because there is not one dedicated 256-bit unit?
  - gameswithgo 8y ago
    > without any penalty. My understanding is that without any penalty was not true, but it is possible the new gen cpus have changed that, I have not firsthand benchmarked it.
  - ajross 8y ago
    > without any penalty Except literally running at half capacity. That doesn't qualify as a "penalty" to you? The point was that AMD advertised support for AVX in a context where you'd expect it to be performance-comparable, and what they shipped was "support" for AVX in the sense that the code wouldn't crash, but wouldn't provide any performance benefit over SSE either.
    - gameswithgo 8y ago
      oh, they are twisting words with the marketing about "no penalty" pretty bad!
    - hajile 8y ago
      https://en.wikichip.org/wiki/intel/frequency_behavior https://en.wikichip.org/wiki/intel/frequency_behavior Intel reduces clockspeeds when running AVX2 and drastically decreases clockspeeds when running AVX512. AMD's slightly smaller unit doesn't need to slow down, so the actual performance difference is smaller than it would appear. Changing frequency takes time. Also, if you are putting through an AVX instruction and a few integer instructions at the same time, the integer instructions will downclock the whole time the AVX pipeline is in use (plus the time before/and after while the clockspeed is being adjusted) decreasing performance for more than just the AVX. There are a couple articles written on the topic. Here's one. https://blog.cloudflare.com/on-the-dangers-of-intels-frequency-scaling/ https://blog.cloudflare.com/on-the-dangers-of-intels-frequen... https://software.intel.com/en-us/forums/intel-isa-extensions/topic/520653 https://software.intel.com/en-us/forums/intel-isa-extensions...

throwaway2048 8y ago

Intel keep positioning optane as "close to dram" preformance (especially with misleading marketing nonsense like this), it does have some advantages over flash, mostly related to random access times, but its nowhere near the orders of magnitude more preformant that something would require to fill the preformance point between DRAM and SSDs. Optane is almost entirely hype, with no substance.

mtgx 8y ago
> Optane is almost entirely hype, with no substance. As it has been from the very first announcement. Intel is being very misleading marketing Xpoint as "memory". It's not even saying it's "close to memory" now. They're literally calling Xpoint memory (as in the same meaning we use for RAM). Considering Xpoint has much lower performance than RAM, I'm starting to believe that maybe the FTC should intervene over "false advertising". It's just too bad the U.S. doesn't have as strong laws as Europe does for false advertising.
imtringued 8y ago
I don't see how a first generation product with similar performance and superior latency to a mature technology (nand) that took decades to develop has no substance. The second generation of Optane is coming out this year and it's going to be an order of magnitude better. It's just a matter of time until nand is obsolete.
- llampx 8y ago
  If Optane is Intel-only, it is not going to replace NAND.
ChuckMcM 8y ago
You and mtgx both mention Optane performance is "not even close to dram." I'm interested in if you have found anyone who has benchmarked the DIMM version with respect to actual DRAM. I see several sites that have benchmarked the Nvme version but this has additional hoops that the DIMM version would not have to jump through and so I've been on the lookout from Anandtech or another reputable source for actual numbers.

djsumdog 8y ago

But what market are they even trying to hit here? DDR4 prices are insane, but home consumers don't run large NUMA systems. Data center admins are going to be able to get the capitol for real DDR4 over Optane. They'd need to be ordering a lot of servers before the price point becomes significant enough that they'd order an Optane configuration and decide to benchmark them. I'd be curious about the real benchmarking at that point. It there a performance boost to simply have more memory, even if some of it is Optane, or is it better to have a lower capacity without the Optane sticks? I have a feeling this will vary heavily by application too.

leetcrew 8y ago
> It there a performance boost to simply have more memory, even if some of it is Optane, or is it better to have a lower capacity without the Optane sticks? I would imagine it depends entirely on whether your working set fits in main memory already. if yes, you're not gonna get much speedup from more memory. but if you have to keep swapping from a traditional SSD, it's gonna be hard for faster main memory to make up for that.
naveen99 8y ago
I thought the real advantage of Optane was bypassing the pcie bus, with much larger bandwidth of dimm: 80GB/s instead of 12GB/s
- tgtweak 8y ago
  DDR4 dimm read throughput is about 20GB/s per dimm. PCIe 3.1 x4 is 16GB/s. I feel very comfortable claiming that these optane dimms will not reach 20GB/s of sustained performance. The advantage here being latency (and thus single queue throughput)
  - naveen99 8y ago
    But pcie bus is shared with other cards. So 8 dimms is 8x faster than 8 pcie cards.

eloff 8y ago

Well at least it can address 3.84 TB of RAM (maybe more, because that's not a multiple of a power of two.) I suppose if you could get 256GB DDR4 DIMMs you'd have 12*256 = 3072 = 3TB of RAM. Yuu'd have to give the RAM cartel your first-born to pay for it, but that would be some machine!