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> AMD which didn't have the funds to run a dedicated design team for laptop/desktops. Given the extremely impressive performance of the 4800H notebook cpus, I'

> AMD which didn't have the funds to run a dedicated design team for laptop/desktops. Given the extremely impressive performance of the 4800H notebook cpus, I'd assume that might be a thing of the past. > AKA, things like hyperthreading are quite a win for servers, but at best are a wash for a desktop use case focused on extremely high single thread perf at the expense of throughput. This might be true for devices like the MacBook Air which are designed for relatively light usage like Office, but I don't see that argument working with their "Pro" lineup, including the iMac Pro and the MacBook Pro. These are devices specifically targeted to a professional audience like graphics designers, 3d artists, software developers or video editors. All of those tasks can be done with decent single-threaded performance, but lots of those tasks also benefit from multithreading. I haven't owned a single MacBook so far and I doubt that'll change anytime soon. Nevertheless, its exciting to see Apple do this move and it'll be interesting how good their CPUs can compare to mobile processors by Intel and AMD.

ebg13 6y ago
> Given the extremely impressive performance of the 4800H notebook cpus, I'd assume that might be a thing of the past. The TDP on those is, what, 3-4x the A12Z?
- sudosysgen 6y ago
  With twice the cores at a higher per-core speed, yes. And also with a much more powerful GPU.
- moooo99 6y ago
  Yeah probably 3-4x the TDP (35-54W) with double the threads, 1.8GHz faster per core clock speed and a relatively powerful on-board graphics unit.
- kllrnohj 6y ago
  TDP is whatever you want it to be. The big cores in an A12Z will pull around 4w each. That means an "unchained" A12Z is a ~16W+ CPU. The 4800H is a 45W TDP, but also has 2x the fast CPU cores. And the binned 4800HS is a 35W TDP, still for 8 cores / 16 threads. So ~2-3x the TDP for 2x the core count and 4x the thread count. Pretty interesting head to head when the Apple dev kits actually show up in people's hands, don't you think?
  - pertymcpert 6y ago
    Not 4W each. Stop saying this.
    - ac29 6y ago
      The linked Anandtech data shows it using 4-5W in a single thread test. That doesn't mean it will use 4-5W/core in a multithreaded test, but thats almost certainly only due to limitations in power delivery and thermals.
    - kllrnohj 6y ago
      SPECint2006 is a single-threaded test: https://images.anandtech.com/doci/14892/specint2006-a13.png https://images.anandtech.com/doci/14892/specint2006-a13.png That's either 4-5W per core or the uncore in an A13 is hugely power hungry. I'm rather positive it's not an extremely bad uncore, so the only other option here is a 4-5w per core power figure. Which also lines up with the voltage/frequency curve numbers: https://images.anandtech.com/doci/14892/a12-fvcurve.png https://images.anandtech.com/doci/14892/a12-fvcurve.png If you have data to support a different number I'm all ears, finding power draw figures in this space is rather difficult, but 4-5W per-core aligns with expectations here. A 1W consumption would be unheard of levels of good.
      - pertymcpert 6y ago
        It’s a meaningless comparison. The 4800H could be a 200W chip if it was “unchained”. Peak burst performance is dynamic in modern CPUs, it’s what you can measure in the real world that matters. Intel TDP doesn’t include the power usage of DRAM and other IO, or the screen, or WiFi or modem (which may have been disabled tbf). Geekbench 5 multi core scores are roughly 7400 vs 3300. Let’s say for example that the Thunder cores are half the perf of the Lightning ones. So that 3300 score might be roughly the perf you could get from 4 x Lightning instead of 2 x Lightning and 4 x Thunder. 4800H has 8 cores. Getting a bit over 2x the performance. But that’s at a TDP of 45W (let’s call it 40W to be more generous). 5W for A13 (well, A13 entire device) vs 40W 4800H. That’s 8x the power draw for 2x performance. Am I wrong?
  - 6y ago
acdha 6y ago
> All of those tasks can be done with decent single-threaded performance, but lots of those tasks also benefit from multithreading Most of those tasks benefit from multiple processors. Multithreading is less clear-cut because you're trading the win for under-optimized code against increased pressure on shared resources (which is one of the reasons why it's opened some windows for security attacks). It's not hard to find pro workloads which perform better without multithreading enabled and considering that Apple will own the entire stack up to some of the most demanding apps they're well positioned to have both solid data on the tradeoffs and architectural changes.
- acdha 6y ago
  Note for the downvoters who might confused: I’m using multithreading in hardware sense of symmetric multithreading (SMT), which Intel refers to as HyperThreading: https://en.wikipedia.org/wiki/Simultaneous_multithreading https://en.wikipedia.org/wiki/Simultaneous_multithreading
  - imtringued 6y ago
    Hyper threading is indeed meant for languages like Python or Javascript that use pointers everywhere. Once you have an optimized workload with little pointer chasing the only other meaningful benefit of SMT come from the fact that you can run floating point workloads alongside integer workloads. That's a pretty rare situation but it does happen sometimes.
    - acdha 6y ago
      That was basically my thought: there are plenty of programs which it can help (almost all business apps) but not all of those are limiting anyone’s work and the feature isn’t free. Having multiple true cores has been common for multiple decades now and I’d be really curious whether a modern chip design team would feel it’s worth investing in if they didn’t already have it. My understanding is that SMT has a power cost comparable to extra cores and given how well Apple’s CPU team has been executing I’d assume there’s been careful analysis behind not implementing it yet.

ebg13 6y ago

> Given the extremely impressive performance of the 4800H notebook cpus, I'd assume that might be a thing of the past. The TDP on those is, what, 3-4x the A12Z?

sudosysgen 6y ago
With twice the cores at a higher per-core speed, yes. And also with a much more powerful GPU.
moooo99 6y ago
Yeah probably 3-4x the TDP (35-54W) with double the threads, 1.8GHz faster per core clock speed and a relatively powerful on-board graphics unit.
kllrnohj 6y ago
TDP is whatever you want it to be. The big cores in an A12Z will pull around 4w each. That means an "unchained" A12Z is a ~16W+ CPU. The 4800H is a 45W TDP, but also has 2x the fast CPU cores. And the binned 4800HS is a 35W TDP, still for 8 cores / 16 threads. So ~2-3x the TDP for 2x the core count and 4x the thread count. Pretty interesting head to head when the Apple dev kits actually show up in people's hands, don't you think?
- pertymcpert 6y ago
  Not 4W each. Stop saying this.
  - ac29 6y ago
    The linked Anandtech data shows it using 4-5W in a single thread test. That doesn't mean it will use 4-5W/core in a multithreaded test, but thats almost certainly only due to limitations in power delivery and thermals.
  - kllrnohj 6y ago
    SPECint2006 is a single-threaded test: https://images.anandtech.com/doci/14892/specint2006-a13.png https://images.anandtech.com/doci/14892/specint2006-a13.png That's either 4-5W per core or the uncore in an A13 is hugely power hungry. I'm rather positive it's not an extremely bad uncore, so the only other option here is a 4-5w per core power figure. Which also lines up with the voltage/frequency curve numbers: https://images.anandtech.com/doci/14892/a12-fvcurve.png https://images.anandtech.com/doci/14892/a12-fvcurve.png If you have data to support a different number I'm all ears, finding power draw figures in this space is rather difficult, but 4-5W per-core aligns with expectations here. A 1W consumption would be unheard of levels of good.
    - pertymcpert 6y ago
      It’s a meaningless comparison. The 4800H could be a 200W chip if it was “unchained”. Peak burst performance is dynamic in modern CPUs, it’s what you can measure in the real world that matters. Intel TDP doesn’t include the power usage of DRAM and other IO, or the screen, or WiFi or modem (which may have been disabled tbf). Geekbench 5 multi core scores are roughly 7400 vs 3300. Let’s say for example that the Thunder cores are half the perf of the Lightning ones. So that 3300 score might be roughly the perf you could get from 4 x Lightning instead of 2 x Lightning and 4 x Thunder. 4800H has 8 cores. Getting a bit over 2x the performance. But that’s at a TDP of 45W (let’s call it 40W to be more generous). 5W for A13 (well, A13 entire device) vs 40W 4800H. That’s 8x the power draw for 2x performance. Am I wrong?
- 6y ago

acdha 6y ago

> All of those tasks can be done with decent single-threaded performance, but lots of those tasks also benefit from multithreading Most of those tasks benefit from multiple processors. Multithreading is less clear-cut because you're trading the win for under-optimized code against increased pressure on shared resources (which is one of the reasons why it's opened some windows for security attacks). It's not hard to find pro workloads which perform better without multithreading enabled and considering that Apple will own the entire stack up to some of the most demanding apps they're well positioned to have both solid data on the tradeoffs and architectural changes.

acdha 6y ago
Note for the downvoters who might confused: I’m using multithreading in hardware sense of symmetric multithreading (SMT), which Intel refers to as HyperThreading: https://en.wikipedia.org/wiki/Simultaneous_multithreading https://en.wikipedia.org/wiki/Simultaneous_multithreading
- imtringued 6y ago
  Hyper threading is indeed meant for languages like Python or Javascript that use pointers everywhere. Once you have an optimized workload with little pointer chasing the only other meaningful benefit of SMT come from the fact that you can run floating point workloads alongside integer workloads. That's a pretty rare situation but it does happen sometimes.
  - acdha 6y ago
    That was basically my thought: there are plenty of programs which it can help (almost all business apps) but not all of those are limiting anyone’s work and the feature isn’t free. Having multiple true cores has been common for multiple decades now and I’d be really curious whether a modern chip design team would feel it’s worth investing in if they didn’t already have it. My understanding is that SMT has a power cost comparable to extra cores and given how well Apple’s CPU team has been executing I’d assume there’s been careful analysis behind not implementing it yet.