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How much of a performance hit would be expected for single threaded performance with the new 16-core processors?

by et2o 9y ago

sp332 9y ago
Top-end Ryzen chips have a TDP of 95W. (Edit: AM4 socket is rated at >140W TDP.) The new sockets are designed for 180W and up, so they will probably run at the same clock frequencies. That means no hit for single-thread performance.
- jplayer01 9y ago
  180W!? That thing is a monster.
  - paulmd 9y ago
    It'll actually probably be more than 180W given that AMD is lowballing their Ryzen 7 TDPs. Those chips are more in the 120-130W range under a typical (non-Prime95) load - so unless they drop the clocks on the 16C chips a bit (which is very plausible), you can expect something closer to 250W TDP. https://www.pcper.com/reviews/Processors/AMD-Ryzen-7-1800X-Review-Now-and-Zen/Power-Consumption-and-Conclusions https://www.pcper.com/reviews/Processors/AMD-Ryzen-7-1800X-R... This is pretty much normal for HEDT chips though. Both Ryzen and Broadwell-E/Haswell-E hit ~230W already when you overclock them - and add another 75-100W for Prime95 loads. I doubt you'll see too many people overclocking the 16C chips even if they're unlocked. You would race right past 300W, probably closer to 400W. You'd need like a 360mm liquid cooler to even think about it.
  - sp332 9y ago
    Of course it's possible that in a given box the new chips will be limited by thermal headroom. For applications like encoding, it's better to have 16x 2.2GHz cores than 8x 3.0GHz cores. But since they have the same architecture, they should be getting the same performance clock-for-clock without a penalty just because they have more cores.
  - drzaiusapelord 9y ago
    Cores come at a power cost. This is why Intel has been hesitant to move to consumer 8 or 16 core CPUs. There's a lot of pushback on using this much power and serious environmental concerns. Intel's engineering has been focused on power savings, so they've actually been going the opposite way for years now on the consumer end. This is also why you won't been seeing these 16c chips on non-specialist Dells and HPs. They'll be high-end workstations and servers only. Joe Consumer or Joe Officeworker doesn't need 16 cores. 6-8c comes in at a more modest power profile, so we'll probably see the industry standardize on 6-8c for a while. I think Intel is now forced to move toward 6-8c now, which may be questionable move for most consumer loads, but if everyone stays under 100w for consumer CPUs I think it'll be okay. I don't want the performance race to be driven by AMD's ideas that burning 200+w for a CPU is reasonable. Outside of specialist applications, its not.
    - mtgx 9y ago
      The main reason they've been doing that is because it's been much easier to lower power consumption per core than increase performance per core. This way they could still claim "significant improvements" year over year. It's also a way better strategy to make "better server chips", because it means you can add more cores.
      - drzaiusapelord 9y ago
        That's assuming there's no trivial single-core advancements possible at this fab size, which there might not be. The run up to Ryzen had a lot of AMD types cheering about "lazy" intel getting beat but Ryzen's per core performance is on par with a 2600k from 2011 and is consistently edged out by a 7700k at the same, or below, pricing. Also Intel's gains have been modest, but very real outside of power savings. CPU passmark benchmark: 2600k (2011) : 8484 7700k (2016): 12196 Both are 4 cores so its a one-to-one comparison. A ~30% increase per core is pretty impressive this late in the Moore's law game. If it wasn't then we'd see Ryzen doing much better per core, but its not. My workloads cannot make effective use of 8 cores so its academic that I can buy a 8c chip now. It would literally be downgrade from my intel for me.

How much of a performance hit would be expected for single threaded performance with the new 16-core processors?

by et2o 9y ago

How much of a performance hit would be expected for single threaded performance with the new 16-core processors?

Top-end Ryzen chips have a TDP of 95W. (Edit: AM4 socket is rated at >140W TDP.) The new sockets are designed for 180W and up, so they will probably run at the same clock frequencies. That means no hit for single-thread performance.

jplayer01 9y ago
180W!? That thing is a monster.
- paulmd 9y ago
  It'll actually probably be more than 180W given that AMD is lowballing their Ryzen 7 TDPs. Those chips are more in the 120-130W range under a typical (non-Prime95) load - so unless they drop the clocks on the 16C chips a bit (which is very plausible), you can expect something closer to 250W TDP. https://www.pcper.com/reviews/Processors/AMD-Ryzen-7-1800X-Review-Now-and-Zen/Power-Consumption-and-Conclusions https://www.pcper.com/reviews/Processors/AMD-Ryzen-7-1800X-R... This is pretty much normal for HEDT chips though. Both Ryzen and Broadwell-E/Haswell-E hit ~230W already when you overclock them - and add another 75-100W for Prime95 loads. I doubt you'll see too many people overclocking the 16C chips even if they're unlocked. You would race right past 300W, probably closer to 400W. You'd need like a 360mm liquid cooler to even think about it.
- sp332 9y ago
  Of course it's possible that in a given box the new chips will be limited by thermal headroom. For applications like encoding, it's better to have 16x 2.2GHz cores than 8x 3.0GHz cores. But since they have the same architecture, they should be getting the same performance clock-for-clock without a penalty just because they have more cores.
- drzaiusapelord 9y ago
  Cores come at a power cost. This is why Intel has been hesitant to move to consumer 8 or 16 core CPUs. There's a lot of pushback on using this much power and serious environmental concerns. Intel's engineering has been focused on power savings, so they've actually been going the opposite way for years now on the consumer end. This is also why you won't been seeing these 16c chips on non-specialist Dells and HPs. They'll be high-end workstations and servers only. Joe Consumer or Joe Officeworker doesn't need 16 cores. 6-8c comes in at a more modest power profile, so we'll probably see the industry standardize on 6-8c for a while. I think Intel is now forced to move toward 6-8c now, which may be questionable move for most consumer loads, but if everyone stays under 100w for consumer CPUs I think it'll be okay. I don't want the performance race to be driven by AMD's ideas that burning 200+w for a CPU is reasonable. Outside of specialist applications, its not.
  - mtgx 9y ago
    The main reason they've been doing that is because it's been much easier to lower power consumption per core than increase performance per core. This way they could still claim "significant improvements" year over year. It's also a way better strategy to make "better server chips", because it means you can add more cores.
    - drzaiusapelord 9y ago
      That's assuming there's no trivial single-core advancements possible at this fab size, which there might not be. The run up to Ryzen had a lot of AMD types cheering about "lazy" intel getting beat but Ryzen's per core performance is on par with a 2600k from 2011 and is consistently edged out by a 7700k at the same, or below, pricing. Also Intel's gains have been modest, but very real outside of power savings. CPU passmark benchmark: 2600k (2011) : 8484 7700k (2016): 12196 Both are 4 cores so its a one-to-one comparison. A ~30% increase per core is pretty impressive this late in the Moore's law game. If it wasn't then we'd see Ryzen doing much better per core, but its not. My workloads cannot make effective use of 8 cores so its academic that I can buy a 8c chip now. It would literally be downgrade from my intel for me.