8 ms·

Ok, where is the benchmark that shows the performance parity? All I've ever seen is comparisons to low power mobile chips. And then extrapolation from there.

by clarry 8y ago

Ok, where is the benchmark that shows the performance parity? All I've ever seen is comparisons to low power mobile chips. And then extrapolation from there. You can't just extrapolate and assume your 2W (or whatever) phone CPU will be like a 95W desktop if you just stick on a heatsink & fan and feed higher voltage & clocks to it. If it were that simple, the CPU manufacturers could fire a whole lot of engineers. It's like, you know, my Honda Accord is reaching performance parity with your Bugatti. (If I extrapolate based on how much I think I'd get performance by sticking in a big turbo and new exhaust, intercooler, and higher RPM redline. It's that simple, right?! No, actually it's not..)

hamilyon2 8y ago
https://homes.cs.washington.edu/~bornholt/post/z3-iphone.html https://homes.cs.washington.edu/~bornholt/post/z3-iphone.htm...
- pfortuny 8y ago
  I wonder: how do they perform those computations? It is not (afaik) that there are compilers available for iOS. Or are there? Honest question, just wondering. Sorry: answered it myself. See the instructions: https://github.com/jamesbornholt/z3-ios https://github.com/jamesbornholt/z3-ios
dsr_ 8y ago
OK, let's go with your analogy. Five days a week you drive fifteen miles to work over roads constrained by traffic, getting up to 60MPH for two minutes and spending the rest of the trip at 0-30. On weekends you sometimes drive two hours to visit friends or go to a special event. The fact is that the Honda is much more appropriate for your life than a Bugatti; 5 days a week you don't do anything that the Accord can't do, and on weekends you could take the money you saved by not buying the Bugatti and rent a Corvette or a Ferrari, and still come out ahead. Most desktops and laptops spend 5 days a week being idle and waiting on RAM, SSDs, spinning disks, or network data... or worse, waiting for human input. During that time, you might as well have a cheap ARM. When you ask for peak power, mostly you could rely on an outboard GPU.
- 666lumberjack 8y ago
  This is an argument for 'ARM chips are a viable CPU option in consumer laptops/desktops', but not for the title's original claim.
  - benj111 8y ago
    I think its a very interesting analogy actually, even if OT. The Bugatti has higher performance but for 90% of people isn't the better car. How long before Intel paint themselves into a corner by going for performance to justify their prices, when everyone just needs a bog standard ARM?
  - dsr_ 8y ago
    The title's original claim is reasonably supported in the article. I'm pointing out that even if ARM development mysteriously stops making gains against x86 development, it's entirely reasonable to think that Apple might announce that the next revision of OS X has an ARM version that runs on their new 16 hour Macbook Air and their new 14 hour Macbook.
    - 666lumberjack 8y ago
      I confess, I hadn't finished reading the original article when I posted my previous comment so I was operating under the assumption that ARM single-core performance was significantly further from parity than it apparently is. My original objection was that an external GPU can't shield you from lag and unresponsiveness in normal, everyday (ie. not designed to take advantage of GPU compute) software, but if the single core performance delta between an A12 and a reasonably recent desktop i7 is genuinely only 20% then that's not an issue.
- _red 8y ago
  My company does some embedded work. The problem with your analogy is that edge-cases drive CPU purchase decisions far more often than you would normally think. A simple example: You have designed an ATM using a lower powered ARM CPU. 99.9% of the use-cases never tax the CPU beyond 30%. However, in specific cases where the ATM must simultaneously access the bill dispenser, printer, and note acceptor the hardware interrupts overwhelm the CPU and leads to 2-3 secs of "CPU lock". After those 3 secs, everything returns to normal. The problem is that the bill dispenser protocol only allows for 1000ms in delay in ack to messages, thus when this situation occurs, the lag is longer than the protocol allows, so it errors out and FUBARs the entire transaction. In this case, even though this only occurs .1% of the time, the existence of this edge-case will mandate that you not use this specific CPU. Spoken another way: The ongoing issue of certain edge-cases will cost much more in the long term, than the extra $50 for a different CPU.
syn0byte 8y ago
“In the space of one hundred and seventy six years the Lower Mississippi has shortened itself two hundred and forty-two miles. That is an average of a trifle over a mile and a third per year. Therefore, any calm person, who is not blind or idiotic, can see that in the Old Oölitic Silurian Period, just a million years ago next November, the Lower Mississippi was upwards of one million three hundred thousand miles long, and stuck out over the Gulf of Mexico like a fishing-pole. And by the same token any person can see that seven hundred and forty-two years from now the Lower Mississippi will be only a mile and three-quarters long, and Cairo [Illinois] and New Orleans will have joined their streets together and be plodding comfortably along under a single mayor and a mutual board of aldermen. There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.” -- Mark Twain
klodolph 8y ago
Intel and ARM are just approaching the same points from different directions, that's all. We can equally say that you can't extrapolate and assume that your 45W x86, with lowered clock and voltage, will fit in the power budget of a mobile phone and still give good performance. But all these companies are throwing a lot of engineering effort at it and making solid progress. There's not some reason why x86, the architecture, should be faster than ARM. Intel has been enjoying a process advantage for many years now, and an enviable R&D budget, but that R&D budget is spent fighting against diminishing returns and in the meantime, competitors are catching up. As long as everyone can buy roughly the same node (a big "if", but looks like we're close enough), diminishing returns will bring everyone closer to parity. But, benchmarks show this a bit better. Geekbench (I'm looking at Single Core): https://browser.geekbench.com/mac-benchmarks https://browser.geekbench.com/mac-benchmarks https://browser.geekbench.com/ios-benchmarks https://browser.geekbench.com/ios-benchmarks iPad Pro 11-inch (iPad8,1) has the A12X at 2.5 GHz, score ~5000. iMac 27-inch retina (iMac18,3) has the i7-7700K at 4.2 GHz, score ~5700. This is not a cherry-picked comparison... this is just a comparison of whatever happens to be top of the line in both categories. Note that multi-core benchmarks will paint a slightly different picture, but that's very natural, since you can get a Mac with 18 core Xeons. Presumably, adding more cores to a mobile processor when you switch to desktop and can handle proportionally higher TDP, while not trivial, is not especially difficult either. I assume that different benchmarks give different results as well. This is just one benchmark I know has results for both platforms.
- MR4D 8y ago
  You make a great point. I remember when I got my 12.9" iPad Pro (gen 2), and the graphics were fast as hell - Waaaaaay faster than my poor Mac Mini could do. Based on that (and yes, both devices are now "old"), I'd trade my Mac Mini performance for the performance of my iPad without hesitation. Bring it, ARM !
  - HeWhoLurksLate 8y ago
    I was going to post a text-heavy reply to you about that, but I decided not to. Essentially, my family got an iPad 4 and bluetooth keyboard case. A few years later, when Apple was prepping for their iPad Pro and positioning tablets as desktop replacements, I found that the work that I did was much easier on the iPad than it was on the Mac Mini (quad-core) that we had, including doing text editing and stuff of the sort. Personally, if someone put an ARM laptop in front of me with a workable, non-spyware OS, I would take it in a heartbeat.
Dylan16807 8y ago
You can't extrapolate too far, but you can reasonably extrapolate a 20% overclock of a chip that's running in low power mode.

by clarry 8y ago

hamilyon2 8y ago

https://homes.cs.washington.edu/~bornholt/post/z3-iphone.html https://homes.cs.washington.edu/~bornholt/post/z3-iphone.htm...

pfortuny 8y ago
I wonder: how do they perform those computations? It is not (afaik) that there are compilers available for iOS. Or are there? Honest question, just wondering. Sorry: answered it myself. See the instructions: https://github.com/jamesbornholt/z3-ios https://github.com/jamesbornholt/z3-ios

dsr_ 8y ago

OK, let's go with your analogy. Five days a week you drive fifteen miles to work over roads constrained by traffic, getting up to 60MPH for two minutes and spending the rest of the trip at 0-30. On weekends you sometimes drive two hours to visit friends or go to a special event. The fact is that the Honda is much more appropriate for your life than a Bugatti; 5 days a week you don't do anything that the Accord can't do, and on weekends you could take the money you saved by not buying the Bugatti and rent a Corvette or a Ferrari, and still come out ahead. Most desktops and laptops spend 5 days a week being idle and waiting on RAM, SSDs, spinning disks, or network data... or worse, waiting for human input. During that time, you might as well have a cheap ARM. When you ask for peak power, mostly you could rely on an outboard GPU.

666lumberjack 8y ago
This is an argument for 'ARM chips are a viable CPU option in consumer laptops/desktops', but not for the title's original claim.
- benj111 8y ago
  I think its a very interesting analogy actually, even if OT. The Bugatti has higher performance but for 90% of people isn't the better car. How long before Intel paint themselves into a corner by going for performance to justify their prices, when everyone just needs a bog standard ARM?
- dsr_ 8y ago
  The title's original claim is reasonably supported in the article. I'm pointing out that even if ARM development mysteriously stops making gains against x86 development, it's entirely reasonable to think that Apple might announce that the next revision of OS X has an ARM version that runs on their new 16 hour Macbook Air and their new 14 hour Macbook.
  - 666lumberjack 8y ago
    I confess, I hadn't finished reading the original article when I posted my previous comment so I was operating under the assumption that ARM single-core performance was significantly further from parity than it apparently is. My original objection was that an external GPU can't shield you from lag and unresponsiveness in normal, everyday (ie. not designed to take advantage of GPU compute) software, but if the single core performance delta between an A12 and a reasonably recent desktop i7 is genuinely only 20% then that's not an issue.
_red 8y ago
My company does some embedded work. The problem with your analogy is that edge-cases drive CPU purchase decisions far more often than you would normally think. A simple example: You have designed an ATM using a lower powered ARM CPU. 99.9% of the use-cases never tax the CPU beyond 30%. However, in specific cases where the ATM must simultaneously access the bill dispenser, printer, and note acceptor the hardware interrupts overwhelm the CPU and leads to 2-3 secs of "CPU lock". After those 3 secs, everything returns to normal. The problem is that the bill dispenser protocol only allows for 1000ms in delay in ack to messages, thus when this situation occurs, the lag is longer than the protocol allows, so it errors out and FUBARs the entire transaction. In this case, even though this only occurs .1% of the time, the existence of this edge-case will mandate that you not use this specific CPU. Spoken another way: The ongoing issue of certain edge-cases will cost much more in the long term, than the extra $50 for a different CPU.

syn0byte 8y ago

“In the space of one hundred and seventy six years the Lower Mississippi has shortened itself two hundred and forty-two miles. That is an average of a trifle over a mile and a third per year. Therefore, any calm person, who is not blind or idiotic, can see that in the Old Oölitic Silurian Period, just a million years ago next November, the Lower Mississippi was upwards of one million three hundred thousand miles long, and stuck out over the Gulf of Mexico like a fishing-pole. And by the same token any person can see that seven hundred and forty-two years from now the Lower Mississippi will be only a mile and three-quarters long, and Cairo [Illinois] and New Orleans will have joined their streets together and be plodding comfortably along under a single mayor and a mutual board of aldermen. There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.” -- Mark Twain

klodolph 8y ago

Intel and ARM are just approaching the same points from different directions, that's all. We can equally say that you can't extrapolate and assume that your 45W x86, with lowered clock and voltage, will fit in the power budget of a mobile phone and still give good performance. But all these companies are throwing a lot of engineering effort at it and making solid progress. There's not some reason why x86, the architecture, should be faster than ARM. Intel has been enjoying a process advantage for many years now, and an enviable R&D budget, but that R&D budget is spent fighting against diminishing returns and in the meantime, competitors are catching up. As long as everyone can buy roughly the same node (a big "if", but looks like we're close enough), diminishing returns will bring everyone closer to parity. But, benchmarks show this a bit better. Geekbench (I'm looking at Single Core): https://browser.geekbench.com/mac-benchmarks https://browser.geekbench.com/mac-benchmarks https://browser.geekbench.com/ios-benchmarks https://browser.geekbench.com/ios-benchmarks iPad Pro 11-inch (iPad8,1) has the A12X at 2.5 GHz, score ~5000. iMac 27-inch retina (iMac18,3) has the i7-7700K at 4.2 GHz, score ~5700. This is not a cherry-picked comparison... this is just a comparison of whatever happens to be top of the line in both categories. Note that multi-core benchmarks will paint a slightly different picture, but that's very natural, since you can get a Mac with 18 core Xeons. Presumably, adding more cores to a mobile processor when you switch to desktop and can handle proportionally higher TDP, while not trivial, is not especially difficult either. I assume that different benchmarks give different results as well. This is just one benchmark I know has results for both platforms.

MR4D 8y ago
You make a great point. I remember when I got my 12.9" iPad Pro (gen 2), and the graphics were fast as hell - Waaaaaay faster than my poor Mac Mini could do. Based on that (and yes, both devices are now "old"), I'd trade my Mac Mini performance for the performance of my iPad without hesitation. Bring it, ARM !
- HeWhoLurksLate 8y ago
  I was going to post a text-heavy reply to you about that, but I decided not to. Essentially, my family got an iPad 4 and bluetooth keyboard case. A few years later, when Apple was prepping for their iPad Pro and positioning tablets as desktop replacements, I found that the work that I did was much easier on the iPad than it was on the Mac Mini (quad-core) that we had, including doing text editing and stuff of the sort. Personally, if someone put an ARM laptop in front of me with a workable, non-spyware OS, I would take it in a heartbeat.

Dylan16807 8y ago

You can't extrapolate too far, but you can reasonably extrapolate a 20% overclock of a chip that's running in low power mode.