7 ms·

A Dive into Ray Tracing Performance on the Apple M1

105 points by tempodox 5y ago

smoldesu 5y ago
For anyone looking to find real-time raytracing examples, this is not it. The author seems to be investigating static renders like you would do in Blender, offloading it to the CPU instead of the GPU. Unsurprisingly, the M1 does not support hardware-accelerated ray tracing. However, almost any CPU made in the last 10 years is capable of software-accelerated ray tracing with software like Pixar's Renderman and the open-source Cycles engine.
- Cyberdog 5y ago
  > software-accelerated ray tracing Is this a particular term/concept, or do you just mean non-hardware-accelerated ray tracing? If the former, what does it mean for something to be "software-accelerated?" If the latter, I apologize if this comes off as nit-picking.
  - smoldesu 5y ago
    When I say software-accelerated, I'm referring to anything that doesn't offload any rendering processes to the GPU. It's not necessarily a turn of phrase, but I think most people familiar with the topic will grok that software rendering = no GPU offload. Though I do understand the desire to be pedantic, because ISAs like this and their SIMD instructions can kinda blur the lines between what constitutes as "hardware accelerated". That's why I try to avoid it as much as possible for the sake of simplicity.
    - tralarpa 5y ago
      I think parent was wondering what the word "accelated" in "software-accelerated" could mean. Faster than what? (faster doing the calculations by hand? :)
      - dragontamer 5y ago
        The concept of "accelerating" raytracing operations on a CPU makes almost no sense. GPUs require acceleration because the memory latency on GPUs is pretty large, caches are small, and GPUs have such huge compute that waiting around for the "next = bvh-tree->left" operation takes a huge amount of time. By making dedicated acceleration structures and hardware, that latency can be mitigated, and the huge compute capabilities of GPUs can be unleashed. ---------- In contrast, CPUs are already really good (relatively) at pointer-dereferencing loops. CPUs have less compute and more memory-optimizations (relative to a GPU anyway).
- CyberDildonics 5y ago
  > However, almost any CPU made in the last 10 years is capable of software-accelerated ray tracing with software like Pixar's Renderman and the open-source Cycles engine. People have been rendering on any CPU they could get their hands on for the last forty years and there is no such thing as "software accelerated ray tracing". That would be like someone saying their car does engine accelerated driving.
  - numpad0 5y ago
    I propose “naturally forced induction”
  - deleted 5y ago
    [deleted]
- Pulcinella 5y ago
  Octane, ProRender, and soon I believe Redshift on macOS use the Metal API for GPU based ray tracing. They are generally faster than CPU based ray tracing (well maybe not ProRender, it’s basically abandoned by Maxxon in favor of Redshift). So while the M1 GPU and most AMD GPUs supported by macOS don’t have hardware specific for accelerating ray tracing, they can still be used to accelerate it over using the CPU. Edit: The article does compare the ray tracing capabilities of the M1 GPU to a RTX 2070. The RTX 2070 obviously crushes it, as the author points out the obviously unfair comparison. The RTX card uses way more power, is much largerx and has hardware acceleration for ray tracing. I am interested in seeing if Apple adds hardware acceleration for RT to future chips (or if they will support external AMD GPUs).
  - lostmsu 5y ago
    > The RTX card uses way more power, is much largerx and has hardware acceleration for ray tracing. Isn't RTX card using less power per ray according to this benchmark? This also applies to ray/size unit I think.
- VMtest 5y ago
  I have seen in old posts that people writing their own raytracers, and that normally means it's on CPU as well right? so their own raytracers are not real-time either
mhh__ 5y ago
I didn't realize Intel had shipped a mobile chip with AVX-512. Also, Intel for the love of God sort out your product names, use a proper system rather than /dev/random Lake
- Tuna-Fish 5y ago
  The code names are not the problem. Basically all companies use engineering code names so that engineers can talk about unreleased products without accidentally revealing things. And since you should not be able to divine anything about the products from them, picking random geographical features is just fine. The problem is that their actual product naming is such a massive mess that people prefer to learn the code names instead of trying to figure out what, exactly, a i7-1165G7 is and how it relates to, say, a i5-11400H?
  - mhh__ 5y ago
    That too, but if the microarchitectures had a numeric identity for example (even in parallel to the xyz lake name) the route to a better numerical ID for CPU's would be easier.
    - masklinn 5y ago
      That's originally what the generation was. Then it became inconvenient so generations and µarchs got disconnected (because marketing, and then more marketing as they had to introduce µarch refreshes because they couldn't move through their plans)
  - Zevis 5y ago
    I had no idea they'd gone back to 4 numbers for some of their CPUs. What does G7 even mean?
    - acqq 5y ago
      Only four? i5-11400H is a real name too: https://www.intel.com/content/www/us/en/products/sku/213805/intel-core-i511400h-processor-12m-cache-up-to-4-50-ghz/specifications.html https://www.intel.com/content/www/us/en/products/sku/213805/...
kristianp 5y ago
It comes to mind to ask why Apple didn't seem to do any binning of their cpus, e.g. use a cpu capable of higher turbo frequency in the pro.
- stkdump 5y ago
  I think they did binning with 7 vs 8 core GPU, but my guess is the more intricate the binning the more complex the whole assembly logistics become, so they probably wanted to avoid that for the initial launch.
ksec 5y ago
For CineBench R23 Score. ( In case anyone will read it the wrong way ) Intel® Core™ i7-1165G7 by default is an 15W TDP CPU, especially true if you are spreading load across all cores. ( 28W if you are on single Core TurboBoost ) It is on 10nm SuperFin ( equivalent to ~TSMC 7nm ), Quad Core and 8 Thread, Not sure about its AVX 512 clock speed limitation I dont have time to dig that up. The Apple M1 is ~ 24W TDP, 8 Core 8 Thread, with 4 being High Efficiency Core on TSMC 5nm. You are looking at a ~60% higher TDP number. The results are still impressive, but needs these additional context before it is consumed. I will also not be surprised if A15 has a major GPU uArch change. ( Something similar to IMG B-Series )
- hajile 5y ago
  M1 is barely 20-25w at the wall. Actual chip peak TDP is more like 14-18w. (EDIT: this is measured from a Mac mini by Anandtech -- a laptop likely has slightly lower TDP due to better binning) Intel chips have much higher peak and sustained actual power usage than their TDP indicates. At the wall, those “15w” systems are actually much closer to 40-60w on sustained loads.
  - dogma1138 5y ago
    It’s very hard to estimate the true power consumption of laptops since they are all primarily fed from the battery not the charger. There are almost no passthroughs anymore even in “gaming” laptops. Only a handful of DTR laptops still employ a passthrough with a high wattage PSU or dual PSU set up and I honestly haven’t seen those for the last 2-3 gens... The last one I’ve seen that had it was a 8700K with dual 1080’s DRT monstrosity.
    - qayxc 5y ago
      > It’s very hard to estimate the true power consumption of laptops since they are all primarily fed from the battery not the charger. That's news to me. I try to keep up to date with laptops, and all the reviewers have pretty accurate power consumption measurements. Even just using the internal reporting reveals quite a few details [1]. Even a "12W" TDP 11th gen Intel CPU can draw up to 50W in turbo mode [2]. The 11th gen "45W" laptop CPUs have a PL2 power draw of 135W [3], which, thermals and VRMs permitting, can be held indefinitely according to the specs (which is what makes Intel's whole TDP-rating useless indeed). So yes, it's very hard indeed to estimate newer laptop's power consumption, but for entirely different reasons. It's primarily the cooling and OEM's choice of how to implement the very loosely defined (Intel!-) specs that define power draw. If you have excellent cooling, there's nothing to stop an 11800H from drawing 135W for minutes at a time... (which can be measured, both internally and from the wall no problem). AMD CPUs on the other hand mostly adhere to the published power rating (give or take 20% - again, cooling permitting and configurable by the OEM). [1] random example: https://bit.ly/34xLKpM https://bit.ly/34xLKpM [2] https://www.anandtech.com/show/16084/intel-tiger-lake-review-deep-dive-core-11th-gen/5 https://www.anandtech.com/show/16084/intel-tiger-lake-review... [3] https://www.itworldcanada.com/article/eight-core-intel-tiger-lake-h-processors-arrive-for-gamers-and-enterprise/447260 https://www.itworldcanada.com/article/eight-core-intel-tiger...
Scene_Cast2 5y ago
Side note. Apple is great at waiting on tech until it's ready, and then making sure everyone knows about it (through a combo of a product launch and marketing). Retina displays, multitouch on touchscreens, and now ARM processors. The notable thing is that Apple makes the enabling incremental change (to a point where the product is good enough for mass market) seem like a step function.
- piyh 5y ago
  The mass adoption that Apple's embrace brings is a step function for things that hit economies of scale thresholds (iPad lidar) and anything with a network effect (airtag).
zokier 5y ago
I think it is neat demonstration how weird the CPU performance has been in recent past that on one hand M1 has very impressive performance, but on the other hand 7 year old CPU puts out competitive numbers. It is also demonstration how much performance we have left behind as we have adopted laptops as the mainstream computing platform/
- qayxc 5y ago
  > It is also demonstration how much performance we have left behind as we have adopted laptops as the mainstream computing platform/ I don't know. Desktops simply tend to have a much longer lifespan and so far every new laptop I owned in the past 10 years outperformed my then desktop PC for that precise reason (at the very least in certain aspects like performance per watt). What I'm rather afraid of is other manufacturers adopting Apple's insane vendor lock-in and total hardware lock-down. Any failure in an M1 system results in complete data loss and a logic board replacement - RAM on SoC, SSD soldered to the board, etc. No more choice and zero upgradability - the oldest components in my current desktop are 12+ years old, but the rest was gradually upgraded (SSD, GPU, CPU, additional RAM, HDD replacements, etc.) Such things won't be possible in brave new world of SoCs...
  - NoPicklez 5y ago
    When it comes to PC Desktops, I do feel there might be more money to be made in still allowing modularity that allows PC enthusiasts and builders to still build their own computers. There is a massive consumer market for it. People aren't going to be buying new desktops every 1-2 years, but many of them will buy new GPU's, or cases, or fans etc. The best part is that we get to upgrade the components that will actually provide better performance. For instance, why would I upgrade my entire machine just for a better graphics chip, if my SSD, CPU and RAM are still in tip top shape, short answer is I wont.
    - judge2020 5y ago
      In reality those things also change depending on your luck and how 'in-sync' you are with the industry. Just upgraded your ddr3 ram in 2013? Get ready for ddr4 which will require both new ram and a new motherboard - and any new high-performance cpu will only be compatible with ddr4 so you're forced to upgrade lest you be stuck on an old standard. This is about to happen with ddr5 as well, by the way.
black7375 5y ago
Whenever I see articles related to the M1, the performance is amazing.
wydfre 5y ago
Can someone tell me how in CUDA you can use RTX cores? I know the main problem with GPU programming is that they hate conditionals - and I was thinking RTX would be vastly different in that regard.

105 points by tempodox 5y ago

For anyone looking to find real-time raytracing examples, this is not it. The author seems to be investigating static renders like you would do in Blender, offloading it to the CPU instead of the GPU. Unsurprisingly, the M1 does not support hardware-accelerated ray tracing. However, almost any CPU made in the last 10 years is capable of software-accelerated ray tracing with software like Pixar's Renderman and the open-source Cycles engine.

Cyberdog 5y ago
> software-accelerated ray tracing Is this a particular term/concept, or do you just mean non-hardware-accelerated ray tracing? If the former, what does it mean for something to be "software-accelerated?" If the latter, I apologize if this comes off as nit-picking.
- smoldesu 5y ago
  When I say software-accelerated, I'm referring to anything that doesn't offload any rendering processes to the GPU. It's not necessarily a turn of phrase, but I think most people familiar with the topic will grok that software rendering = no GPU offload. Though I do understand the desire to be pedantic, because ISAs like this and their SIMD instructions can kinda blur the lines between what constitutes as "hardware accelerated". That's why I try to avoid it as much as possible for the sake of simplicity.
  - tralarpa 5y ago
    I think parent was wondering what the word "accelated" in "software-accelerated" could mean. Faster than what? (faster doing the calculations by hand? :)
    - dragontamer 5y ago
      The concept of "accelerating" raytracing operations on a CPU makes almost no sense. GPUs require acceleration because the memory latency on GPUs is pretty large, caches are small, and GPUs have such huge compute that waiting around for the "next = bvh-tree->left" operation takes a huge amount of time. By making dedicated acceleration structures and hardware, that latency can be mitigated, and the huge compute capabilities of GPUs can be unleashed. ---------- In contrast, CPUs are already really good (relatively) at pointer-dereferencing loops. CPUs have less compute and more memory-optimizations (relative to a GPU anyway).
CyberDildonics 5y ago
> However, almost any CPU made in the last 10 years is capable of software-accelerated ray tracing with software like Pixar's Renderman and the open-source Cycles engine. People have been rendering on any CPU they could get their hands on for the last forty years and there is no such thing as "software accelerated ray tracing". That would be like someone saying their car does engine accelerated driving.
- numpad0 5y ago
  I propose “naturally forced induction”
- deleted 5y ago
  [deleted]
Pulcinella 5y ago
Octane, ProRender, and soon I believe Redshift on macOS use the Metal API for GPU based ray tracing. They are generally faster than CPU based ray tracing (well maybe not ProRender, it’s basically abandoned by Maxxon in favor of Redshift). So while the M1 GPU and most AMD GPUs supported by macOS don’t have hardware specific for accelerating ray tracing, they can still be used to accelerate it over using the CPU. Edit: The article does compare the ray tracing capabilities of the M1 GPU to a RTX 2070. The RTX 2070 obviously crushes it, as the author points out the obviously unfair comparison. The RTX card uses way more power, is much largerx and has hardware acceleration for ray tracing. I am interested in seeing if Apple adds hardware acceleration for RT to future chips (or if they will support external AMD GPUs).
- lostmsu 5y ago
  > The RTX card uses way more power, is much largerx and has hardware acceleration for ray tracing. Isn't RTX card using less power per ray according to this benchmark? This also applies to ray/size unit I think.
VMtest 5y ago
I have seen in old posts that people writing their own raytracers, and that normally means it's on CPU as well right? so their own raytracers are not real-time either

mhh__ 5y ago

I didn't realize Intel had shipped a mobile chip with AVX-512. Also, Intel for the love of God sort out your product names, use a proper system rather than /dev/random Lake

Tuna-Fish 5y ago
The code names are not the problem. Basically all companies use engineering code names so that engineers can talk about unreleased products without accidentally revealing things. And since you should not be able to divine anything about the products from them, picking random geographical features is just fine. The problem is that their actual product naming is such a massive mess that people prefer to learn the code names instead of trying to figure out what, exactly, a i7-1165G7 is and how it relates to, say, a i5-11400H?
- mhh__ 5y ago
  That too, but if the microarchitectures had a numeric identity for example (even in parallel to the xyz lake name) the route to a better numerical ID for CPU's would be easier.
  - masklinn 5y ago
    That's originally what the generation was. Then it became inconvenient so generations and µarchs got disconnected (because marketing, and then more marketing as they had to introduce µarch refreshes because they couldn't move through their plans)
- Zevis 5y ago
  I had no idea they'd gone back to 4 numbers for some of their CPUs. What does G7 even mean?
  - acqq 5y ago
    Only four? i5-11400H is a real name too: https://www.intel.com/content/www/us/en/products/sku/213805/intel-core-i511400h-processor-12m-cache-up-to-4-50-ghz/specifications.html https://www.intel.com/content/www/us/en/products/sku/213805/...

kristianp 5y ago

It comes to mind to ask why Apple didn't seem to do any binning of their cpus, e.g. use a cpu capable of higher turbo frequency in the pro.

stkdump 5y ago
I think they did binning with 7 vs 8 core GPU, but my guess is the more intricate the binning the more complex the whole assembly logistics become, so they probably wanted to avoid that for the initial launch.

ksec 5y ago

For CineBench R23 Score. ( In case anyone will read it the wrong way ) Intel® Core™ i7-1165G7 by default is an 15W TDP CPU, especially true if you are spreading load across all cores. ( 28W if you are on single Core TurboBoost ) It is on 10nm SuperFin ( equivalent to ~TSMC 7nm ), Quad Core and 8 Thread, Not sure about its AVX 512 clock speed limitation I dont have time to dig that up. The Apple M1 is ~ 24W TDP, 8 Core 8 Thread, with 4 being High Efficiency Core on TSMC 5nm. You are looking at a ~60% higher TDP number. The results are still impressive, but needs these additional context before it is consumed. I will also not be surprised if A15 has a major GPU uArch change. ( Something similar to IMG B-Series )

hajile 5y ago
M1 is barely 20-25w at the wall. Actual chip peak TDP is more like 14-18w. (EDIT: this is measured from a Mac mini by Anandtech -- a laptop likely has slightly lower TDP due to better binning) Intel chips have much higher peak and sustained actual power usage than their TDP indicates. At the wall, those “15w” systems are actually much closer to 40-60w on sustained loads.
- dogma1138 5y ago
  It’s very hard to estimate the true power consumption of laptops since they are all primarily fed from the battery not the charger. There are almost no passthroughs anymore even in “gaming” laptops. Only a handful of DTR laptops still employ a passthrough with a high wattage PSU or dual PSU set up and I honestly haven’t seen those for the last 2-3 gens... The last one I’ve seen that had it was a 8700K with dual 1080’s DRT monstrosity.
  - qayxc 5y ago
    > It’s very hard to estimate the true power consumption of laptops since they are all primarily fed from the battery not the charger. That's news to me. I try to keep up to date with laptops, and all the reviewers have pretty accurate power consumption measurements. Even just using the internal reporting reveals quite a few details [1]. Even a "12W" TDP 11th gen Intel CPU can draw up to 50W in turbo mode [2]. The 11th gen "45W" laptop CPUs have a PL2 power draw of 135W [3], which, thermals and VRMs permitting, can be held indefinitely according to the specs (which is what makes Intel's whole TDP-rating useless indeed). So yes, it's very hard indeed to estimate newer laptop's power consumption, but for entirely different reasons. It's primarily the cooling and OEM's choice of how to implement the very loosely defined (Intel!-) specs that define power draw. If you have excellent cooling, there's nothing to stop an 11800H from drawing 135W for minutes at a time... (which can be measured, both internally and from the wall no problem). AMD CPUs on the other hand mostly adhere to the published power rating (give or take 20% - again, cooling permitting and configurable by the OEM). [1] random example: https://bit.ly/34xLKpM https://bit.ly/34xLKpM [2] https://www.anandtech.com/show/16084/intel-tiger-lake-review-deep-dive-core-11th-gen/5 https://www.anandtech.com/show/16084/intel-tiger-lake-review... [3] https://www.itworldcanada.com/article/eight-core-intel-tiger-lake-h-processors-arrive-for-gamers-and-enterprise/447260 https://www.itworldcanada.com/article/eight-core-intel-tiger...

Scene_Cast2 5y ago

Side note. Apple is great at waiting on tech until it's ready, and then making sure everyone knows about it (through a combo of a product launch and marketing). Retina displays, multitouch on touchscreens, and now ARM processors. The notable thing is that Apple makes the enabling incremental change (to a point where the product is good enough for mass market) seem like a step function.

piyh 5y ago
The mass adoption that Apple's embrace brings is a step function for things that hit economies of scale thresholds (iPad lidar) and anything with a network effect (airtag).

zokier 5y ago

I think it is neat demonstration how weird the CPU performance has been in recent past that on one hand M1 has very impressive performance, but on the other hand 7 year old CPU puts out competitive numbers. It is also demonstration how much performance we have left behind as we have adopted laptops as the mainstream computing platform/

qayxc 5y ago
> It is also demonstration how much performance we have left behind as we have adopted laptops as the mainstream computing platform/ I don't know. Desktops simply tend to have a much longer lifespan and so far every new laptop I owned in the past 10 years outperformed my then desktop PC for that precise reason (at the very least in certain aspects like performance per watt). What I'm rather afraid of is other manufacturers adopting Apple's insane vendor lock-in and total hardware lock-down. Any failure in an M1 system results in complete data loss and a logic board replacement - RAM on SoC, SSD soldered to the board, etc. No more choice and zero upgradability - the oldest components in my current desktop are 12+ years old, but the rest was gradually upgraded (SSD, GPU, CPU, additional RAM, HDD replacements, etc.) Such things won't be possible in brave new world of SoCs...
- NoPicklez 5y ago
  When it comes to PC Desktops, I do feel there might be more money to be made in still allowing modularity that allows PC enthusiasts and builders to still build their own computers. There is a massive consumer market for it. People aren't going to be buying new desktops every 1-2 years, but many of them will buy new GPU's, or cases, or fans etc. The best part is that we get to upgrade the components that will actually provide better performance. For instance, why would I upgrade my entire machine just for a better graphics chip, if my SSD, CPU and RAM are still in tip top shape, short answer is I wont.
  - judge2020 5y ago
    In reality those things also change depending on your luck and how 'in-sync' you are with the industry. Just upgraded your ddr3 ram in 2013? Get ready for ddr4 which will require both new ram and a new motherboard - and any new high-performance cpu will only be compatible with ddr4 so you're forced to upgrade lest you be stuck on an old standard. This is about to happen with ddr5 as well, by the way.

black7375 5y ago

Whenever I see articles related to the M1, the performance is amazing.

wydfre 5y ago

Can someone tell me how in CUDA you can use RTX cores? I know the main problem with GPU programming is that they hate conditionals - and I was thinking RTX would be vastly different in that regard.