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| ▲ | toast0 4 days ago | parent | next [-] | | I think the fundamental difference between an Apple CPU and an Intel/AMD CPU is Apple does not play in the megahertz war. The Apple M1 chip, launched in 2020 clocks at 3.2GHz; Intel and AMD can't sell a flagship mobile processor that clocks that low. Zen+ mobile Ryzen 7s released Jan 2019 have a boost clock of 4 GHz (ex: 3750H, 3700U); mobile Zen2 from Mar 2020 clock even higher (ex: 4900H at 4.4, 4800H at 4.2). Intel Tiger Lake was hitting 4.7 Ghz in 2020 (ex: 1165G7). If you don't care to clock that high, you can reduce space and power requirements at all clocks; AMD does that for the Zen4c and Zen5c cores, but they don't (currently) ship an all compact core mobile processor. Apple can sell a premium branded CPU where there's no option to burn a lot of power to get a little faster; but AMD and Intel just can't, people may say they want efficiency, but having higher clocks is what makes an x86 processor premium. In addition to the basic efficiency improvements you get by having a clock limit, Apple also utilizes wider execution; they can run more things in parallel, this is enabled to some degree by the lower clock rates, but also by the commitment to higher memory bandwidth via on package memory; being able to count on higher bandwidth means you can expect to have more operations that are waiting on execution rather than waiting on memory, so wider execution has more benefits. IIRC, Intel released some chips with on package memory, but they can't easily just drop in a couple more integer units onto an existing core. The weaker memory model of ARM does help as well. The M series chips have a much wider out of order window, because they don't need to spend as much effort on ordering constraints (except when running in the x86 support mode); this also helps justify wider execution, because they can keep those units busy. I think these three things are listed in order of impact, but I'm just an armchair computer architecture philosopher. | | |
| ▲ | fluoridation 3 days ago | parent | next [-] | | Does anyone actually care at all about frequencies? I care if my task finishes quickly. If it can finish quickly at a low frequency, fine. If the clock runs fast but the task doesn't, how is that a benefit? My understanding is that both Intel and AMD are pushing high clocks not because it's what consumers want, but because it's the only lever they have to pull to get more gains. If this year's CPU is 2% faster than your current CPU, why would you buy it? So after they have their design they cover the rest of the target performance gain by cranking the clock, and that's how you get 200 W desktop CPUs. >the commitment to higher memory bandwidth via on package memory; being able to count on higher bandwidth means you can expect to have more operations that are waiting on execution rather than waiting on memory, so wider execution has more benefits. I believe you could make a PC (compatible) with unified memory and a 256-bit memory bus, but then you'd have to make the whole thing. Soldered motherboard, CPU/GPU, and RAM. I think at the time the M1 came out there weren't any companies making hardware like that. Maybe now that x86 handhelds are starting to come out, we may see laptops like that. | | |
| ▲ | Yizahi 3 days ago | parent [-] | | It's only recently when consumer software has become truly multithreaded. Historically there were major issues with that until very recently. Remember Bulldozer fiasco? They bet on the parallel execution more than Intel at the same time, e.g. same price Intel chip was 4 core, while AMD had 8 cores (consumer market). Single thread performance had been the deciding factor for decades. Even today AMDs outlier SKUs with a lot of cores and slightly lower frequencies (like 500 MHz lower or so) are not a topic of the day in any media or forum community. People talk about either top of the line SKU or something with low core count but clocking high enough to be reasonable for lighter use. Releasing low frequency high core count part for consumers would be greeted with questions, like "what for is this CPU?". | | |
| ▲ | fluoridation 3 days ago | parent | next [-] | | Are we just going to pretend that frequency = single-thread performance? I'm fine with making that replacement mentally, I just want to confirm we're all on the same page here. >Releasing low frequency high core count part for consumers would be greeted with questions, like "what for is this CPU?". It's for homelab and SOHO servers. It won't get the same attention as the sexy parts... because it's not a sexy part. It's something put in a box and stuff in a corner to chug away for ten years without looking at it again. | |
| ▲ | wmf 3 days ago | parent | prev | next [-] | | low frequency high core count part for consumers That's not really what we're talking about. Apple's cores are faster yet lower clocked. (Not just faster per clock but absolutely faster.) So some people are wondering if Intel/AMD targeting 6 GHz actually reduced performance. | |
| ▲ | gigatexal 3 days ago | parent | prev [-] | | But the OS has been able to take advantage of it since mountain lion with grand central dispatch. I could be wrong with the code name. This makes doing parallel things very easy. But most every OS can. | | |
| ▲ | astrange 3 days ago | parent [-] | | Parallelism is actually very difficult and libdispatch is not at all perfect for it. Swift concurrency is a newer design and gets better performance by being /less/ parallel. (This is mostly because resolving priority inversions turns out to be very important on a phone, and almost noone designs for this properly because it's not important on servers.) |
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| ▲ | cosmic_cheese 3 days ago | parent | prev [-] | | > Apple can sell a premium branded CPU where there's no option to burn a lot of power to get a little faster; but AMD and Intel just can't, people may say they want efficiency, but having higher clocks is what makes an x86 processor premium. I think this is very context dependent. Is this a big, heavy 15”+ desktop replacement notebook where battery life was never going to be a selling point in the first place? One of those with a power brick that could be used as a dumbbell? Sure, push those clocks. In a machine that’s more balanced or focused on portability however, high clock speeds do nothing but increase the likelihood of my laptop sounding like a jet and chewing through battery. In that situation higher clocks makes a laptop feel less premium because it’s worse at its core use case for practically no gain in exchange. |
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| ▲ | exmadscientist 4 days ago | parent | prev | next [-] | | > I have to assume that amd and intel would like similar chips They historically haven't. They've wanted the higher single-core performance and frequency and they've pulled out all the stops to get it. Everything had been optimized for this. (Also, they underinvested in their uncores, the nastiest part of a modern processor. Part of the reason AMD is beating Intel right now despite being overall very similar is their more recent and more reliable uncore design.) They are now realizing that this was, perhaps, a mistake. AMD is only now in a position to afford to invest otherwise (they chose quite well among the options actually available to them, in my opinion), but Intel has no such excuse. | | |
| ▲ | x0x0 4 days ago | parent [-] | | Not arguing, but I would think there is (and always has been) very wide demand for fastest single core perf. From all the usual suspects? Thank you. | | |
| ▲ | MBCook 3 days ago | parent | next [-] | | Oh there certainly is. And there’s a reason Apple works hard for really fast single core performance. For a lot of tasks it still matters. I suspect one of the issues is that pushing the clock is a really easy way to get an extra 2% so you can claim the crown of fastest or try to win benchmarks. It’s easy to fall into a trap of continuing to do that over and over. But we know the long-term result. You end up blasting out a ton of heat and taking up a ton of power, even though you may only be 10% faster than a competitor who did things differently. Or worse you try to optimize for ever increasing clocks and get stuck like the Pentium 4. As said up thread, no one really compares Apple CPU speeds with megahertz. That’s partially because Apple doesn’t talk about it or emphasize it which makes it more difficult, and partially because it’s not like you have a choice anyway. It would never happen but it would be interesting to see how things would develop if it was possible to simply ban talking about clock speeds somehow. What would that do to the market? | |
| ▲ | exmadscientist 3 days ago | parent | prev [-] | | Only Intel and AMD actually attempt to deliver fastest single-thread performance. Apple has made the decision that almost-but-not-quite-the-fastest is good enough for them. And that has made all the difference. | | |
| ▲ | aurareturn 3 days ago | parent [-] | | You’ve been saying that this whole thread but you’ve not provided any evidence. |
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| ▲ | bryanlarsen 4 days ago | parent | prev | next [-] | | What's it due to? At least this, probably more. - more advanced silicon architecture. Apple spends billions to get access to the latest generation a couple of years before AMD. - world class team, with ~25 years of experience building high speed low power chips. (Apple bought PA Semi to make these chips, which was originally the team that build the DEC StrongARM). And then paid & treated them properly, unlike Intel & AMD - a die budget to spend transistors for performance: the M chips are generally quite large compared to the competition - ARM's weak memory model also helps, but it's very minor IMO compared to the above 3. | | |
| ▲ | aurareturn 3 days ago | parent | next [-] | | - a die budget to spend transistors for performance: the M chips are generally quite large compared to the competition
This is a myth. Apple chips are no bigger than the competition. For example, base M4 is smaller than Lunar Lake but is more efficient and 35% faster. M4 Pro is smaller than Strix Halo by a large margin but generally matches/exceeds the performance. Only the M4 Max is very large but it has no equivalent in the x86 world. | |
| ▲ | x0x0 4 days ago | parent | prev | next [-] | | interesting, ty re: apple getting exclusive access to the best fab stuff: https://appleinsider.com/articles/23/08/07/apple-has-sweethe... . Interesting. | | |
| ▲ | MBCook 3 days ago | parent [-] | | At the same time they have a guaranteed customer who will buy the chips. How many other companies would be willing to try a process with a 30% success rate? I think Apple helps them with money (loan?) to get some of the equipment or build the new lines. In exchange they get first shot at buying capacity. And of course Apple is certainly paying for the privilege of the best process. At least more than other companies are willing. And they must buy a pretty tremendous volume across a couple of sizes. It benefits both companies, otherwise they wouldn’t do it. |
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| ▲ | astrange 3 days ago | parent | prev | next [-] | | > And then paid & treated them properly, unlike Intel & AMD Relatively properly. Nothing like the pampering software people get. I've heard Mr. Srouji is very strict about approving promotions personally etc. (…by heard I mean I read Blind posts) | |
| ▲ | gigatexal 4 days ago | parent | prev [-] | | How many of those engineers remain, didn't a lot go to Nuvia that was then bought by Qualcomm? | | |
| ▲ | bryanlarsen 4 days ago | parent | next [-] | | Sure, but they were there long enough to train and instill culture into the others. And of course, since the acquisition in 2008 they've had access to the top new grads and experienced engineers. If you're coming out top of your class at an Ivy or similar you're going to choose Apple over Intel or AMD both because of rep and the fact that your offer salary is much better. P.S. hearsay and speculation, not direct experience. I haven't worked at Apple and anybody who has is pretty closed lip. You have to read between the lines. P.P.S. It's sort of a circular argument. I say Apple has the best team because they have the best chip && they have the best chip because they have the best team. But having worked (briefly) in the field, I'm very confident that their success is much more likely due to having the best team rather than anything else. | |
| ▲ | MBCook 3 days ago | parent | prev [-] | | And isn’t that the reason people think some of the most recent Qualcomm chips are so much better? |
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| ▲ | ThrowawayR2 3 days ago | parent | prev | next [-] | | Intel and AMD are after the very high profit margins of the enterprise server market. They have much less motivation to focus on power efficient mobile chips which are less profitable for them. Apple's primary product is consumer smartphones and tablets so they are solely focused on power efficient mobile chips. | |
| ▲ | bsder 3 days ago | parent | prev [-] | | > Genuinely asking -- what is it due to? Mostly memory/cache subsystem. Apple was willing to spend a lot of transistors on cache because they were optimizing the chips purely for mobile and can bury the extra cost in their expensive end products. You will note that after the initial wins from putting stonking amounts of cache and memory bandwidth in place, Apple has not had any significant performance jump beyond the technology node improvements. | | |
| ▲ | x0x0 3 days ago | parent | next [-] | | I still don't understand though. Given their profit margins, the fact that they're shipping m chips in eg $1k computers means it's a $150 part. There's tons of people that would pay $300+ for an equivalent perf + heat x86 competitor. | |
| ▲ | astrange 3 days ago | parent | prev | next [-] | | They aren't aiming for performance in the first place. It's a coincidence that it has good performance. They're aiming for high performance/power ratios. | |
| ▲ | MBCook 3 days ago | parent | prev [-] | | Wasn’t the M3 a reasonable increase and the M4 much more significant than that? The M2 was certainly nothing amazing in jump. |
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