9 ms·
The fact that we are even able to realistically compare a CPU in an ultralight laptop with no fan to an i9 is absolutely amazing. To me that would be an upgrade
by bb123 6y ago
The fact that we are even able to realistically compare a CPU in an ultralight laptop with no fan to an i9 is absolutely amazing. To me that would be an upgrade even if performance is a complete wash.
- api 6y agoYeah seeing a MacBook Air beat an i9 is hilarious. I think this should put arguments over X86 efficiency disadvantages to bed. The X86 is obviously a huge boat anchor. There is no other explanation for this monstrous of a performance efficiency gap... unless Apple has invented something fundamentally new that has never been done in the entire history of CPU design. I doubt that.
- jchw 6y agoMy intuition is that x86's wasted die space on instruction decoding, backwards compatibility, etc. can be spent on making bigger and wider cores, and this seems to be what M1 is doing. However, there are still some other aspects to consider. One is Apple's process lead against both Intel and AMD. The next is the memory situation; it'll be interesting to see if increased latency from more conventional configurations will change the dynamics much. (I suspect no, but some people suspect yes.)
- vlovich123 6y agoThe x86 space for decoding is tiny. The inefficiencies have to come from elsewhere and at least partially from the node difference. An architecturally big one is that x86 only implements SeqCst for atomics whereas looser memory models can allow multi-process programs to be written more efficiently (which they have been already for mobile). In other words I think the problem has to do with the semantics of x86 more than the syntax of decoding x86.
- R0b0t1 6y agoThis was explored in detail in another thread, it seems most of the gains are from looser memory ordering.
- navaati 6y agoBy the way, does someone knows where RISC-V stands regarding this ?
- gpderetta 6y agoI think that Apple "just" [1] picked a very happy place in the parameter space: lower clock means that main memory (which is already lower latency than usual) is "nearer" to the cpu plus a larger L1 with a shorter latency (3 cycles). These (plus probably a larger amount of sustainable outstanding misses) imply that the cpu stalls less which means that they can sustain a larger ILP [2]. A better branch predictor (which is rumored to be best in class, although I haven't seen any in depth analysis) means that they can usefully have a larger reorder buffer and extract even more ILP and memory level parallelism. Finally the large width can take advantage of the extracted parallelism. The weaker memory model should help extracting additional memory level parallelism, but I doubt that ordering has large impact. M1 is quite good even when running in TSO mode. [1] of course they need to be commended for this, they went against the usual wisdom, probably because their CPU was designed to be low power first then high performance, not the other way around. [2] typically the average ILP for normal applications is 1.5 instructions per cycle, but the variance is high, so if you reduce the amount of cycles the cpu is stalled, the ILP can go up fast.
- vlovich123 6y agoYou’re right. Like I said, atomics are one space. Another as you point out is that the memory architecture is pretty unique at providing high throughout and lower latency than traditional x86 architectures. I suspect Intel and AMD will adjust their roadmaps accordingly as a result of this new competition.
- formerly_proven 6y ago
- raverbashing 6y agoYes I agree, it's more the semantics and the legacy of x86 (page sizes, MMU, memory models - even though Rosetta still runs faster than x86) than simply decoding.
- colejohnson66 6y agoIt’s not the instruction decoder that wastes die space. In fact, it’s less than 5% of the die (on Skylake).[0] [0]: https://pbs.twimg.com/media/EXFJLebXkAYkXTr?format=jpg&name=large https://pbs.twimg.com/media/EXFJLebXkAYkXTr?format=jpg&name=... In case that link dies, it’s from [1] which is linked from [2] [1]: https://mobile.twitter.com/GPUsAreMagic/status/1256866465577394181 https://mobile.twitter.com/GPUsAreMagic/status/1256866465577... [2]: https://travisdowns.github.io/blog/2020/05/26/kreg2.html https://travisdowns.github.io/blog/2020/05/26/kreg2.html
- hajile 6y ago> it’s less than 5% of the die It would be equally fair to say that the same die uses less than 5% of it's space for the integer ALUs. It could also be said that the decode unit is so complex that it takes as much die space as all the integer ports put together. SRAM may use most of the die, but it isn't using huge amounts of power most of the time as it's static. Those big SIMD units are also powered off when not used (no doubt it's the same with the other ALUs). In contrast, the entire 5% of the die that makes up the decoder never power gates and is always running flat out. By size it's the same as leaving all your integer cores running full-out all the time. The bigger issue seems to be that neither AMD nor Intel have been able to make those units much wider over the years which puts a hard limit on total throughput (they've hinted that the power cost on widening the decoder is very big which would mean loads of power used for diminishing returns).
- _ph_ 6y agoIt isn't so much the decoder space, but the decoder complexity that is the disadvantage of x86 chips. The problem is that the instructions have varying lengths. Only when it has decoded an instruction, the chip knows where the next instruction starts. ARM-instructions are all the same length, so the instructions can be decoded in parallel without "knowing" the previous instruction. That lets Apple go much wider (8 instead of 4) with the instruction decoders.
- wwright 6y agoWell, Apple has managed to move all the way down to a 5nm process while Intel still hasn't made it past 14nm. AFAIK that's the largest limiting factor for Intel. I can't speak to why they have been stuck there for so long.
- jtxx 6y agoI’m not sure about 5nm but I know they were targeting 7nm and something broke that set them back till 2022/23. Not looking good for intel https://www.tomshardware.com/news/intel-announces-delay-to-7nm-processors-now-one-year-behind-expectations https://www.tomshardware.com/news/intel-announces-delay-to-7...
- robin_reala 6y agoLeaving aside the fact that process size is a marketing term these days, I’m currently typing this on a previous-gen Macbook Air with a 10nm Intel CPU. They’re definitely not stuck on 14nm.
- dralley 6y agoThey are effectively stuck on 14nm. They are unable to produce 10nm chips at scale at an acceptable yield, and the power and performance characteristics are not as good as expected either. There's a reason the only laptops getting 10nm are low-quantity premium laptops.
- jdxcode 6y agoyes but GP is still correct in general if not in the specifics. Practically speaking they can fit way more transistors on the die which translates to more power for more types of things whether it's M1 or 888.
- dkersten 6y ago> Leaving aside the fact that process size is a marketing term these days There was a youtube video where the guy used a scanning electron microscope to compare gate sizes between 14nm intel and 7nm AMD and both were basically the exact same size. The conclusion was that the term is useful only to compare a single companies product line against other offerings in that line (eg comparing Intel's 14nm to Intel's 20nm makes sense but comparing Intel to AMD based on node size is meaningless).
- doikor 6y agoI doubt the instruction set is the only (or even the main) advantage M1 has. Apple just has been hiring some of the best talent in the field for a long time now that have been working on their phone/tablet chips and now used their talents on the M1. There is a lot you can do to improve a CPU without changing the instruction set or manufacturing process just by doing a better job at designing the CPU itself. (look at Ryzen 5000 series with 15 to 20% IPC gain over the 3000/4000 series while staying on the same manufacturing process for example) Basically there is a lot to gain just by doing a better design on the CPU itself. Also faster CPUs/GPUs allows one to build faster CPUs/GPUs just because as with more compute around you can run simulations faster/with more accuracy thus allowing faster development/better designs.
- KiranRao0 6y agoHere's a really good article describing why the M1 chip is so fast. Tl;dr it's a beefy CPU with a massive reorder buffer, and a bunch of discrete subsystems (gpu, ml core, dsp, etc). https://debugger.medium.com/why-is-apples-m1-chip-so-fast-3262b158cba2 https://debugger.medium.com/why-is-apples-m1-chip-so-fast-32...
- lliamander 6y agoNot to mention that the M1 has a manufacturing node advantage (which can really help with perf-per-watt).
- spamizbad 6y agoI think people should pay more attention to the LPDDR4X RAM that's tightly coupled to the CPU and likely has significantly less latency and more bandwidth than anything on the Ryzen or i9. This is critical to keeping their wide design fed, and if you swapped this out with standard DDR3200 you'd see some lackluster numbers. Both Intel and AMD try to overcome the memory wall with larger caches and clever prefetching, which is going to chew up more die space and power than x86 decoders.
- AceJohnny2 6y agoHow would one benchmark memory performance (DRAM latency & bandwidth) on the various chips?
- spamizbad 6y agoAbove my pay grade! You probably operating with a fixed speed on M1 so you can't intentionally cripple it, but it would be interesting to see "What would this look like if Apple had paired it with standard DDR4-3200?". AMD's Zen core's are known to respond well to lower latency RAM, but in the PC space you're not getting anything close to what Apple has with the LPDDR4x on package. You could try benchmarking the Intel and Ryzen chips with DDR4 5000 and try carefully tuning the memory frequency and timing to find the right balance of bandwidth and latency.
- jeffbee 6y ago> in the PC space you're not getting anything close to what Apple has with the LPDDR4x on package. I mean, that's exactly how an 11th Gen Core laptop is constructed.
- kllrnohj 6y ago> but in the PC space you're not getting anything close to what Apple has with the LPDDR4x on package. You can run basically any Intel CPU at DDR4-4266 without any issue. Or you can go thread ripper and laugh in quad channel memory. Or Intel x299 and triple-channel memory. You don't have to tune anything, either, the RAM comes pre-tuned with the right timings in the XMP profile.
- cbozeman 6y agoLPDDR4X-4266 memory and its right on the chip. I'd really like to see what AMD could do with a huge die that combines 8 Zen 3 cores, 16 GB of LPDDR4X-4266, and their GPU all on a single chip. I'm very excited about the performance that Apple has been able to generate with this silicon, but these tests don't put anything to bed. You're giving up extreme choice and expandability for performance by going the M1 route. You can spend $1700 for a Mac Mini with 16 GB of RAM and a 2 TB SSD, but that's what you're stuck with. Forever. Until its time to buy a new computer. People who bought into AMD's AM4 platform at the start were able to go up from the 1000 series to the 3000 series, able to upgrade their RAM from nearly any size to 64 GB, and able to upgrade their SSDs by slotting in a new NVMe drive. To say nothing of the GPU, which for developers of specific solutions, is becoming a serious concern. Also if you game in your spare time, you're at a disadvantage not just due to the Apple ecosystem, but also limited by the GPU. For most of us, our machines are disposable. Even though I still build myself a new workstation every 2-3 years, I never bother selling it, I just give it away to family because for me its not worth the hassle, and then I order $3-4000 in parts and build a new one all over again. So buying the new Mac Mini made sense for me, although I opted to go with the base model for $699 so I could evaluate it and determine if going "all-in" for a higher-end model made sense (it does), but not for one second am I under the illusion that this chip is going to be the death of x86.
- vmception 6y agoStores should have a new category: Apple M1 and Only Fans
- the_arun 6y agoImagine AWS launching ec2 instances with M1 chips!
- Aperocky 6y agoThey have graviton, which is already more efficient by a huge margin (against intel per dollar).
- dylan604 6y agoMore efficient than Intel i-series or more efficient than M1?
- Aperocky 6y agomore efficient per dollar against their intel counterparts.
- greatpatton 6y agoAWS can set their own price (or subsidize it to keep people on their cloud), more efficient per $ is not really a good way to judge how good is the chip, though it is a good measure for how much money will stay in your pocket.
- the_arun 6y agoTrue, but I believe graviton is still not like M1. Do they support i386 / backward compatible?
- heavyset_go 6y agoM1 is not i386 compatible. macOS uses a translation layer through Rosetta 2 for x86 compatibility.
- mbell 6y ago
- soheil 6y agoJust a quick note, the MacBook Air is by no means "ultralight" even by Apple standards, 2017 MacBook for example was more than twice lighter. Thinkpad laptops are also measurably lighter than any current generation MacBook.
- lostlogin 6y ago> more than twice lighter. Under half the weight?
- Aperocky 6y agoThat's not true though, the air weighs at 1.27 kg whereas the 12" macbook weighs at 0.92 kg. That's about a quarter lighter but not anywhere near half.
- fredsted 6y agoYes, Apple's current lineup is a little confusing. The 13" Pro and 13" Air are so similar, and almost the same weight. I still use a 12" MacBook, and it's just amazingly small and light. If Apple makes a 12" MacBook with a M1, it would be awesome. A dream machine for me.
- soheil 6y agoAgreed! Even dreamier if they bring back the magsafe and upgrade to the current keyboard with function keys.
- x87678r 6y agoYou're not wrong but the article is still a 9th gen laptop i9. A desktop i9 is quicker - https://cpu.userbenchmark.com/Compare/Intel-Core-i9-9880H-vs-Intel-Core-i9-10900K/m750169vs4071 https://cpu.userbenchmark.com/Compare/Intel-Core-i9-9880H-vs....
- mackal 6y agoI still don't understand why people can't get that not all i9s are the same. That's literally what this title is implying ... Which isn't even the article's title ... Maybe someone will edit it so people stop assuming they mean the i9-10900k ...
- jeffbee 6y agoAlso i9 doesn't mean "fast" it just means it is the most expensive of its generation. You will get much closer to M1 performance using a mobile 11th gen i7 than with any i9.
- mandrizzle 6y agoIntel likely intended people to mix up the processors like this because they could easily have marketed a distinction between them.
- alexchantavy 6y agoBut the Ryzen 3900X is a desktop processor, right? This is crazy - definitely was not expecting the M1 to be _better_ than the 3900X.
- freeAgent 6y agoIt’s a desktop processor, but also last generation. The latest Ryzens are the 5xxxx series, and the performance improvement is substantial.
- andreime 6y agoalso ... single core performance m1, like the a* chips are great at single core performance m1, like the a* chips are underwhelming at multi-core performance last gen ryzen was competitive at single core performance, and great at multicore current gen ryzen is great at both
- dmitriid 6y agoAll these gains will be entirely swallowed by software in a few years.
- seddin 6y agoElectron apps or worse.
- babuskov 6y agoOne can easily foresee this actually happening if chip designs start to diverge from the standard and the only common thing is that you can run a browser on it.
- dmitriid 6y agoNot just Electron apps. I've seen people on Twitter gushing about how seamless and flicker-free is switching between screens and resolutions on M1. And yet, there's literally no reason why it can't be done today, now, on the existing hardware. Instant waking from sleep was one of the key points in M1's presentation. Something my 2007 model Macbook Pro could do. But then the subsequent releases of MacOS just couldn't do that. Despite significant increases in disk speed, and CPU speed, and RAM speed. We are effecivey running supercomputers. And we can't seem to be able to do anything with them.
- astrange 6y agoWhat makes you think AMD/Intel can do instant display resolution changes?
- dmitriid 6y agoWhat exactly prevents them from doing just that? 3.2 GHz not enough to negotiate screen resolution? HDMI/DP link that M1 produces is some otherworldly HDMI/DP not available to anyone else? I have an example right here, in front of me. I have a Dell monitor. My Macbook Pro is connected to it via Thunderbolt/USB-C->HDMI. My Windows box is connected to it via DP. So, I'm on my Windows box, playing a game. I turn on my Macbook Pro, and it shows me a proper resolution on the laptop screen. The laptop sees that the display is on, and I see that many windows are missing because they are on the other screen. So, I switch my display from DP (coming from Windows) to HDMI (coming from my Macbook Pro). The only thing that changes is the source input to the display. And yet. Macbook takes up to 10 seconds to renegotiate the resoltion again. First it slowly disconnects from the display, screws up the resolution, brings all the windows to the laptop screen. Then it reconnects to the display, renegotiates the resolution and restores the windows as they are supposed to be. Why? And what is so magical about the M1 CPU that it seemingly can do this in an instant? There's nothing magical: whoever implements all this crap simply doesn't care. And in a couple of years M1 (or M1 X Pro whatever) will forget how to to that just as MacOS forgot how it could instantly wake up from sleep 12 years ago.
- JohnTHaller 6y agoI think they're more light than ultralight. Otherwise the performance stands. LG Gram 2020: 2.07 lbs MacBook 2017: 2.03 lbs MacBook Air 2020: 2.8 lbs MacBook Pro 2020: 3.0 lbs
- ogre_codes 6y agoApple deliberately kept the form factors of these the same for this launch. It will be interesting seeing where they go from here form factor wise. Also... I suspect benchmarking the LG or the 12" MacBook versus the Air would be pretty humiliating.
- acqq 6y agoMacBook Air 2019 (Intel): 2.75 MacBook Pro 2019 (Intel): 3.02 As far as I see the M1 models aren't heavier than the Intel ones? But run much longer before they have to be recharged, spending much less power.