4 ms·

The thing is the performance isn't exactly erratic. It's purely a function of the cooling available and the target skin temperature. This doesn't mean you can'

by jpgvm 12y ago

The thing is the performance isn't exactly erratic. It's purely a function of the cooling available and the target skin temperature. This doesn't mean you can't "trust" it. It just means you should do what you should have -always- done which is buy machines in metal chassis (and of reasonable size) if you want passive cooling or get a machine with a decent thermal design and active cooling (fans). Trying to spin this into FUD seems a little desperate.

acqq 12y ago
Yes, the author expects something unrealistic and than presents his unfulfilled expectations as the problem. There's no technical reason that every notebook had to have the same cooling technology. That the processor can adjust to the cooling available is actually a good thing. And mobile phones behave exactly the same.
- osivertsson 12y ago
  It doesn't matter if it is unrealistic from an engineering perspective, what matters is end-user experience. I've heard technically clueless people complain that their new highend Core-M laptop is slower than their old laptop when they just do work (ie+powerpoint+excel+mail), and they are frustrated. Right then it doesn't matter that the new laptop only weighs half of the old one and still has much better battery life, work is still done mostly at a desk with power nearby.
  - acqq 12y ago
    The top speed is actually the function of the heat generated, and you can generate more when you have better cooling, as simple as that. If some "expert" claimed to the users that by looking at the processor name they can know how fast something is it's the "expert" who isn't.
    - m_mueller 12y ago
      > top speed is actually the function of the heat generated That knowledge is rather dated and probably goes back to the Pentium 4 era. Top speed is a function of heat, but also of the process technology and the concurrency available+used. It's best to wrap your head around it by going back to first principles: > The dynamic power consumed by a CPU is approximately proportional to the CPU frequency, and to the square of the CPU voltage: > P = C V^2 f > where C is capacitance, f is frequency, and V is voltage. [1] Capacitance goes down with smaller transistors, voltage and frequency goes up with higher sequential performance given the same architecture. So, by replacing the need for sequential performance with more concurrency (vectorization/multicore/gpu acceleration), the need for power goes down dramatically. Process technology is another big factor. On a related note: Comparing ARM with Core M just using some concurrency using benchmarks is not really comparing Apples to Apples - I expect Core M to have a higher sequential performance - so if you want to have the same performance on ARM, you'll need more concurrency in the software. [1] http://en.wikipedia.org/wiki/CPU_power_dissipation http://en.wikipedia.org/wiki/CPU_power_dissipation
      - seanmcdirmid 12y ago
        I believe you mean parallelism, not concurrency right? Concurrency is dealing (correctly) with more things at the same time, parallelism is doing more things at the same time. The Pentium 4 had a very deep pipeline, which got very hot and wasn't fast compared to its clock. The pentium M went back to more instruction level parallelism via shallower parallel pipes (multi core came later). I don't think ARM is competitive with Intel even with parallel benchmarks; Intel does performance well and doesn't play many tricks with it, ARM's advantage has always been power efficiency and cost.
        m_mueller 12y ago
        > I believe you mean parallelism, not concurrency right? Concurrency is dealing (correctly) with more things at the same time, parallelism is doing more things at the same time. Yes, parallelism makes more sense in this context. I wanted to express it in a more general way because running multiple programs on different cores at the same time I understand as concurrency, which is also made more efficient by parallel performance rather than sequential - IMO the terms are a little bit fuzzy at times, i.e. it's not that easy to convey the ideas behind parallel programming easily such that there is no ambiguity. Edit: About ARM vs. Core M in benchmarks: After looking at it again, apparently the two are still quite far apart, you were right about their performance numbers: [1] [1] http://www.fool.com/investing/general/2014/09/22/intel-corporations-core-m-significantly-outpaces-a.aspx http://www.fool.com/investing/general/2014/09/22/intel-corpo...
Kurtz79 12y ago
My thoughts exactly. The same cited article "with sobering conclusions" from Anandtech says exactly that. More than erratic, I would say it's very "flexible", since it can be used by different devices with different requirements in terms of performance and skin temperature.
higherpurpose 12y ago
The problem is except for Asus, which usually has great cooling designs, most Core-M based devices are going to overheat. Because Intel overpromised on the capabilities of Core-M (5W TDP with 2.9GHZ Turbo!).
bryanlarsen 12y ago
That seems like a good heuristic. However, the Yoga Pro 3 has both a metal base and a fan, and it's the worst performer. That's because it has a really low target temperature. They have to do this because there are so many different ways to hold a Yoga Pro 3 that they cannot allow any part of the laptop to get uncomfortably hot in the hand.
jusssi 12y ago
Only looking at the specs, it looks very similar to 5th-gen Core i7 U-series, with just significantly lower TDP. http://ark.intel.com/compare/85215,84672 http://ark.intel.com/compare/85215,84672 If that's the case, no wonder it gets bogged down by thermal throttling.
- Kurtz79 12y ago
  The Anand article is spot-on I believe. It's not a processor that is meant to be doing sustained heavy work (compiling, gaming, simulations), but attend to small burts of CPU loads and then go back to low power mode. It seems to me it would be more than enough for office work, remote ssh, (non flash) web browsing, e-mail etc. Anyone buying a thin and light device like the ones mounting this processor, and expecting the performance of a desktop replacement laptop have unreasonable expectations to start with.

by jpgvm 12y ago

acqq 12y ago

Yes, the author expects something unrealistic and than presents his unfulfilled expectations as the problem. There's no technical reason that every notebook had to have the same cooling technology. That the processor can adjust to the cooling available is actually a good thing. And mobile phones behave exactly the same.

osivertsson 12y ago
It doesn't matter if it is unrealistic from an engineering perspective, what matters is end-user experience. I've heard technically clueless people complain that their new highend Core-M laptop is slower than their old laptop when they just do work (ie+powerpoint+excel+mail), and they are frustrated. Right then it doesn't matter that the new laptop only weighs half of the old one and still has much better battery life, work is still done mostly at a desk with power nearby.
- acqq 12y ago
  The top speed is actually the function of the heat generated, and you can generate more when you have better cooling, as simple as that. If some "expert" claimed to the users that by looking at the processor name they can know how fast something is it's the "expert" who isn't.
  - m_mueller 12y ago
    > top speed is actually the function of the heat generated That knowledge is rather dated and probably goes back to the Pentium 4 era. Top speed is a function of heat, but also of the process technology and the concurrency available+used. It's best to wrap your head around it by going back to first principles: > The dynamic power consumed by a CPU is approximately proportional to the CPU frequency, and to the square of the CPU voltage: > P = C V^2 f > where C is capacitance, f is frequency, and V is voltage. [1] Capacitance goes down with smaller transistors, voltage and frequency goes up with higher sequential performance given the same architecture. So, by replacing the need for sequential performance with more concurrency (vectorization/multicore/gpu acceleration), the need for power goes down dramatically. Process technology is another big factor. On a related note: Comparing ARM with Core M just using some concurrency using benchmarks is not really comparing Apples to Apples - I expect Core M to have a higher sequential performance - so if you want to have the same performance on ARM, you'll need more concurrency in the software. [1] http://en.wikipedia.org/wiki/CPU_power_dissipation http://en.wikipedia.org/wiki/CPU_power_dissipation
    - seanmcdirmid 12y ago
      I believe you mean parallelism, not concurrency right? Concurrency is dealing (correctly) with more things at the same time, parallelism is doing more things at the same time. The Pentium 4 had a very deep pipeline, which got very hot and wasn't fast compared to its clock. The pentium M went back to more instruction level parallelism via shallower parallel pipes (multi core came later). I don't think ARM is competitive with Intel even with parallel benchmarks; Intel does performance well and doesn't play many tricks with it, ARM's advantage has always been power efficiency and cost.
      - m_mueller 12y ago
        > I believe you mean parallelism, not concurrency right? Concurrency is dealing (correctly) with more things at the same time, parallelism is doing more things at the same time. Yes, parallelism makes more sense in this context. I wanted to express it in a more general way because running multiple programs on different cores at the same time I understand as concurrency, which is also made more efficient by parallel performance rather than sequential - IMO the terms are a little bit fuzzy at times, i.e. it's not that easy to convey the ideas behind parallel programming easily such that there is no ambiguity. Edit: About ARM vs. Core M in benchmarks: After looking at it again, apparently the two are still quite far apart, you were right about their performance numbers: [1] [1] http://www.fool.com/investing/general/2014/09/22/intel-corporations-core-m-significantly-outpaces-a.aspx http://www.fool.com/investing/general/2014/09/22/intel-corpo...

Kurtz79 12y ago

My thoughts exactly. The same cited article "with sobering conclusions" from Anandtech says exactly that. More than erratic, I would say it's very "flexible", since it can be used by different devices with different requirements in terms of performance and skin temperature.

higherpurpose 12y ago

The problem is except for Asus, which usually has great cooling designs, most Core-M based devices are going to overheat. Because Intel overpromised on the capabilities of Core-M (5W TDP with 2.9GHZ Turbo!).

bryanlarsen 12y ago

That seems like a good heuristic. However, the Yoga Pro 3 has both a metal base and a fan, and it's the worst performer. That's because it has a really low target temperature. They have to do this because there are so many different ways to hold a Yoga Pro 3 that they cannot allow any part of the laptop to get uncomfortably hot in the hand.

jusssi 12y ago

Only looking at the specs, it looks very similar to 5th-gen Core i7 U-series, with just significantly lower TDP. http://ark.intel.com/compare/85215,84672 http://ark.intel.com/compare/85215,84672 If that's the case, no wonder it gets bogged down by thermal throttling.

Kurtz79 12y ago
The Anand article is spot-on I believe. It's not a processor that is meant to be doing sustained heavy work (compiling, gaming, simulations), but attend to small burts of CPU loads and then go back to low power mode. It seems to me it would be more than enough for office work, remote ssh, (non flash) web browsing, e-mail etc. Anyone buying a thin and light device like the ones mounting this processor, and expecting the performance of a desktop replacement laptop have unreasonable expectations to start with.