5 ms·

[citation needed]? I've not seen any useful IO benchmarks of POWER in a long time, if ever, and they've never been remotely comparable to more commodity systems

[citation needed]? I've not seen any useful IO benchmarks of POWER in a long time, if ever, and they've never been remotely comparable to more commodity systems, since POWER almost always gets used in the huge systems you mention...

valarauca1 13y ago
Citation Given: http://www.extremetech.com/computing/181102-ibm-power8-openpower-x86-server-monopoly http://www.extremetech.com/computing/181102-ibm-power8-openp... Power8 has 230GB/s of bandwidth to ram compared to a Xeon's 85GB/s. That's nearly triple (270.5%) a XEON's I/O speed.
- dekhn 13y ago
  ummm... I see STREAM copy benchmarks for Xeon reporting at least double the number you cite. Further, a benchmark like this is complicated. How is RAM divided between sockets? What's the bandiwdth between a CPU and memory in another socket? etc etc
  - deleted 13y ago
    [deleted]
    - dekhn 13y ago
      Thanks, but I neither track my score nor care that you think I'm condescending.
      - 15characterlimi 13y ago
        Are you talking to yourself?
      - dang 13y ago
        The (now-deleted) comment you replied to was right. Your comment would have been much better without "ummm...". All: please don't use snark in HN comments. It violates civility and degrades the discourse.
        dekhn 13y ago
        It's your opinion that "umm..." is snark. It's what I would say in person if I doubted your claims. Notice that I actually had a question and it was answered in the thread, which I acknowledged.
        dang 13y ago
        Happy to take your word for it. I could well be hyperallergic after years of wincing at gratuitous unpleasantness in HN comments (edit: and, to be fair, having contributed my own share of it). In person, of course, tone of voice would reveal everything about "ummm...". Either way, please understand that the intent behind comments like this is in no way personal. The idea is to send feedback signals into the community about the kind of discourse we want to cultivate.
        dekhn 13y ago
        You're microoptimizing. Spending time to complain about an "um" or and "uh" which had no semantic content implied other than what um or uh normally means is pointless. You can't micromanage every conversation, nor should you. Focus on outright negative comments. mine was surprise and disbelief (which was later rectified by data). System working as expect, no SNAFUs!
        queensnake 13y ago
        If it was a snotty 'ummmm', I personally would object to it in real life, too. And I think others would as well. Also, you don't need 'ums' in writing.
  - valarauca1 13y ago
    Unable to respond, citation not given. But I'll respond anyways. It looks like you have GB and Gb per second confused. One is 8x the other. admin-magazine: claims 120Gb/s [1] intel claims: 246Gb/s [2] Independent claims on intel forums range from 120-175Gb/s [3] Intel's cut sheet for their own latest generation xeon states it only supports 25GB/s (200Gb/s) memory bandwidth [4] [1] http://www.admin-magazine.com/HPC/Articles/Finding-Memory-Bottlenecks-with-Stream http://www.admin-magazine.com/HPC/Articles/Finding-Memory-Bo... [2] http://www.intel.com/content/www/us/en/benchmarks/server/xeon-e7-v2/xeon-e7-v2-4s-stream.html http://www.intel.com/content/www/us/en/benchmarks/server/xeo... [3] https://software.intel.com/en-us/forums/topic/383121 https://software.intel.com/en-us/forums/topic/383121 [4] http://ark.intel.com/products/75465/Intel-Xeon-Processor-E3-1285-v3-8M-Cache-3_60-GHzz http://ark.intel.com/products/75465/Intel-Xeon-Processor-E3-...
    - dekhn 13y ago
      Reporting memory bandwidth in Gb is misleading. The page you cite here: http://www.intel.com/content/www/us/en/benchmarks/server/xeon-e7-v2/xeon-e7-v2-4s-stream.html http://www.intel.com/content/www/us/en/benchmarks/server/xeo... shows a triad bandwidth (STREAM) of 246,313.60 MB (megabytes) per second which is 240 GB (gigaBYTES) / sec. If I'm making a mistake I'm sure we can work it out.
      - justincormack 13y ago
        That 240GB is on 4 sockets, so corresponds roughly to the 85GB/socket cited above, while the Power7 compared was about half the Intel, so about 50GB/socket, while Power8 is allegedly at 240GB/socket.
        dekhn 13y ago
        Thanks for the clarification. HN took ~30-40 minutes before it would show a reply option for this post, so I went ahead and acknowledged the performance difference in a reply to my original reply (ugh). Anyway, that's great to see such high memory bandwidth per socket, rather than summed over the whole machine.
  - dekhn 13y ago
    A reply to myself since I can't reply to the informative reply below (thanks HN). The RAM benchmarks for Xeon are per-machine (summed over sockets, presumably with no cross-socket traffic, since cross-socket memory is 1/2 speed) while the Power8 benchmarks are per socket. That is indeed impressive. no wonder google is considering these. memory bandwidth is indeed critical.

valarauca1 13y ago

Citation Given: http://www.extremetech.com/computing/181102-ibm-power8-openpower-x86-server-monopoly http://www.extremetech.com/computing/181102-ibm-power8-openp... Power8 has 230GB/s of bandwidth to ram compared to a Xeon's 85GB/s. That's nearly triple (270.5%) a XEON's I/O speed.

dekhn 13y ago
ummm... I see STREAM copy benchmarks for Xeon reporting at least double the number you cite. Further, a benchmark like this is complicated. How is RAM divided between sockets? What's the bandiwdth between a CPU and memory in another socket? etc etc
- deleted 13y ago
  [deleted]
  - dekhn 13y ago
    Thanks, but I neither track my score nor care that you think I'm condescending.
    - 15characterlimi 13y ago
      Are you talking to yourself?
    - dang 13y ago
      The (now-deleted) comment you replied to was right. Your comment would have been much better without "ummm...". All: please don't use snark in HN comments. It violates civility and degrades the discourse.
      - dekhn 13y ago
        It's your opinion that "umm..." is snark. It's what I would say in person if I doubted your claims. Notice that I actually had a question and it was answered in the thread, which I acknowledged.
        dang 13y ago
        Happy to take your word for it. I could well be hyperallergic after years of wincing at gratuitous unpleasantness in HN comments (edit: and, to be fair, having contributed my own share of it). In person, of course, tone of voice would reveal everything about "ummm...". Either way, please understand that the intent behind comments like this is in no way personal. The idea is to send feedback signals into the community about the kind of discourse we want to cultivate.
        dekhn 13y ago
        You're microoptimizing. Spending time to complain about an "um" or and "uh" which had no semantic content implied other than what um or uh normally means is pointless. You can't micromanage every conversation, nor should you. Focus on outright negative comments. mine was surprise and disbelief (which was later rectified by data). System working as expect, no SNAFUs!
        queensnake 13y ago
        If it was a snotty 'ummmm', I personally would object to it in real life, too. And I think others would as well. Also, you don't need 'ums' in writing.
- valarauca1 13y ago
  Unable to respond, citation not given. But I'll respond anyways. It looks like you have GB and Gb per second confused. One is 8x the other. admin-magazine: claims 120Gb/s [1] intel claims: 246Gb/s [2] Independent claims on intel forums range from 120-175Gb/s [3] Intel's cut sheet for their own latest generation xeon states it only supports 25GB/s (200Gb/s) memory bandwidth [4] [1] http://www.admin-magazine.com/HPC/Articles/Finding-Memory-Bottlenecks-with-Stream http://www.admin-magazine.com/HPC/Articles/Finding-Memory-Bo... [2] http://www.intel.com/content/www/us/en/benchmarks/server/xeon-e7-v2/xeon-e7-v2-4s-stream.html http://www.intel.com/content/www/us/en/benchmarks/server/xeo... [3] https://software.intel.com/en-us/forums/topic/383121 https://software.intel.com/en-us/forums/topic/383121 [4] http://ark.intel.com/products/75465/Intel-Xeon-Processor-E3-1285-v3-8M-Cache-3_60-GHzz http://ark.intel.com/products/75465/Intel-Xeon-Processor-E3-...
  - dekhn 13y ago
    Reporting memory bandwidth in Gb is misleading. The page you cite here: http://www.intel.com/content/www/us/en/benchmarks/server/xeon-e7-v2/xeon-e7-v2-4s-stream.html http://www.intel.com/content/www/us/en/benchmarks/server/xeo... shows a triad bandwidth (STREAM) of 246,313.60 MB (megabytes) per second which is 240 GB (gigaBYTES) / sec. If I'm making a mistake I'm sure we can work it out.
    - justincormack 13y ago
      That 240GB is on 4 sockets, so corresponds roughly to the 85GB/socket cited above, while the Power7 compared was about half the Intel, so about 50GB/socket, while Power8 is allegedly at 240GB/socket.
      - dekhn 13y ago
        Thanks for the clarification. HN took ~30-40 minutes before it would show a reply option for this post, so I went ahead and acknowledged the performance difference in a reply to my original reply (ugh). Anyway, that's great to see such high memory bandwidth per socket, rather than summed over the whole machine.
- dekhn 13y ago
  A reply to myself since I can't reply to the informative reply below (thanks HN). The RAM benchmarks for Xeon are per-machine (summed over sockets, presumably with no cross-socket traffic, since cross-socket memory is 1/2 speed) while the Power8 benchmarks are per socket. That is indeed impressive. no wonder google is considering these. memory bandwidth is indeed critical.