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ARM’s Cortex A53: Tiny but Important
- user6723 3y agoARM Cortex A53 is one of the few (or only?) modern CPUs without spectre problems. Other CPUs do have mitigations but they only lessen the problem.
- sylware 3y agoHopefully, we get worldwide non-toxic IP cores with enough performance from RISC-V to replace those abominations.
- shjake 3y agoIMHO ARM is one of the best things that ever happened in the computer industry. > non-toxic IP cores with enough performance from RISC-V Why would anyone also their designs to be used for free or for cheaper than ARM does?
- Yujf 3y agoCompetition. Multiple vendors can compete with RISC-V while ARM can prevent all competition with licenses, if it really will happen is a different case, but I'm optimistic about the potential.
- shjake 3y agoPossibly, but historically it high end semiconductors seem to turn into a winner takes all market more often than not. If that’s the case it’s probably preferable to have someone like ARM at the top than Intel or Nvidia.
- sylware 3y agonope, it is would be better if it was RISC-V.
- shjake 3y agoWhy (besides religious reasons)? I don’t see how can high-end/competitive RISC-V cores could be fully open/free and without that how is it better than ARM.
- sylware 3y agoThere is nothing religious here. arm and x86 are not royalty free ISAs, RISC-V is, then RISC-V is mechanically a better choice, until it does a good enough job.
- snvzz 3y ago>and without that how is it better than ARM. Only ARM can license ARM cores to others. Using RISC-V, any company who can design their own cores can also offer them for licensing. There's already tens of companies offering hundreds of cores for licensing. This is much better than ISA-enforced vendor lock-in, which is the situation with x86 and ARM.
- rektide 3y agoIt's winner take all in a competitive scenario, maybe. Winner is all is what RISC-V is trying to make happen.
- rektide 3y agoMost people want to build things not cores, the cores aren't the core competency. So the hope is, release what cores you have & let others improve it for you. Western Digital's swer-v core is seemingly an example of this thinking.
- shjake 3y agoWould you not expect companies which actually want to make to cores to have an advantage? And the companies that don’t want to make it their core business but can afford enough resources (e.g. Google, Apple, Amazon) would just use them to leverage their core products. I could only see this on the lower end where margins/required R&D investment are relatively low.
- rektide 3y agoI expect going it alone will get totally owned by everyone else working together.
- Symmetry 3y agoThere's a lot to be said for open source ISAs like RISC-V. But it's a lot harder to create a top of the line open source microarchitecture implementing it that's competitive to closed source designs. A Linux kernel developer can make changes and test them several times a day for a cost in electricity measured in cents. An equivalent build/test cycle on a CPU core is going to be north of a month and a million dollars. Simulation helps but to optimize speed and yield you really need to build the chips and due to physical effects that's a process with much weaker abstraction barriers than software development. So I'm skeptical that we'll ever have cutting edge open source microarchitectures.
- sylware 3y agoI am not talking about open source architecture, but more about a worldwide non-toxic ISA: namely anybody can create FREELY a RISC-V microarchitecture AT WORLWIDE SCALE, and that closed or open, which you cannot with arm or x86. Ofc, worldwide royalty free is not enough (or just be allowed to implement the ISA...), silicium is really about performance, and I sincerely hope RISC-V will end up providing microarchitectures (open or not) "good enough" to do the job. I am perfectly aware RISC-V will fail if not providing at scale really good implementations. Rumors say "really performant" implementations are not expected before 2024.
- klelatti 3y ago> namely anybody can create FREELY a RISC-V microarchitecture AT WORLWIDE SCALE The problem with this argument is that it ignores the cost of creating the microarchitecture. It’s almost certainly cheaper to license an Arm A series core than to create a comparable RISC-V core from scratch. Sure we have a firm like SiFive that licenses RV cores to third parties but the existence of firms like Arm and SFive shouldn’t be taken for granted. If rumour has it SiFive were almost taken over by Intel. Thankfully Nvidia were stopped from buying Arm. If you wish for Arm’s demise you may get the end of their business model and that probably isn’t a great outcome.
- sylware 3y ago
- mhh__ 3y agoArticle could use a more aggressive editor, slightly bloated.
- speed_spread 3y agoSomeday somebody will say that about someone else's DNA.
- hoc 3y agoIf that could be checked and fixed on a regular basis, I'll be fine with that.
- silvestrov 3y agoIt would be interesting with a graph of "performance per watt". Mobile phones often have background tasks that does not need much CPU power. A53 seems very suitable for this, so it would be nice with some idea of how much power phones saves by using A53 for this instead of a high performance core.
- nfriedly 3y agoGeekerwan on YouTube tests the performance and effiency of different cores at different frequencies. This is one good example where the A55 and A510 (successors to the A53) are graphed at around 15:40: https://youtu.be/s0ukXDnWlTY https://youtu.be/s0ukXDnWlTY (honestly, the whole video is pretty informative)
- monocasa 3y agoIt really depends on the workload. Modern thoughts on the matter trend towards a design called "race to sleep" where even your efficiency cores are still pretty beefy relative to an A53. That model is focused on quickly turning the core on, running through all of the work, and going back to sleep, rather than staying on longer on a much weaker core. Doing this effectively requires OS support to coalesce timer deadlines to bunch up as much work as possible on each wakeup cycle. But with software support the model is very effective which is why you see most e-cores these days being relatively beefy OoOE cores that can leave the A53 in the dust. Whether that's Icestorm in the M1, Goldmont on Intel, or A57s on big.LITTLE ARM SoCs.
- realjhol 3y agoIn regard to the A55 and the A510, can anyone explain the design goals of these? Do they refine the A53 as a "small" CPU? Or are they larger more featureful CPUs?
- deleted 3y ago[deleted]
- Findecanor 3y agon my impression, the later ones are all supposed to be successors of the previous but within about the same chip area. The A55 is basically a refined A53 with support for DynamIQ. The point of the A510 was support for ARMv9 with SVE2, but it is wider also because people expect faster processors. To amortise the cost of the larger back-end it lost 32-bit support and there's an option to make a cluster of two share the same FP/SIMD/SVE unit and L2 cache.
- realjhol 3y agoThe A53 is a fantastic workhorse for all kinds of embedded workloads. I was worried bloat would creep into later models, while the tried and true A53 moves toward obsolescence. From what you're saying, it seems like they are trying not to get carried away with it.
- zokier 3y agoThere is also A34 if A510 gets too big for your tastes
- Findecanor 3y agoThe ARM Cortex-A520 was announced yesterday. Apparently ARM realised that the A510 was too big, and removed an ALU unit (back to two like the A55). News: <https://www.anandtech.com/show/18871/arm-unveils-armv92-mobile-architecture-cortex-x4-a720-and-a520-64bit-exclusive/4 https://www.anandtech.com/show/18871/arm-unveils-armv92-mobi...> Discussion: <https://news.ycombinator.com/item?id=36109916 https://news.ycombinator.com/item?id=36109916>
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- borissk 3y agoSoCs that have only A53 cores are terribly slow. Recently played with a Motorola Moto G22 phone with a Mediatek Helio G37. The phone has a nice design, 5 cameras, enough RAM and storage (4GB/64GB), but the UI is laggy and slow, installing and lunching apps, rendering web pages takes a lot of time.
- joshuaissac 3y agoThey are meant to be used in a big.LITTLE configuration. So the A53 cores should be active in the low-power mode, and more powerful cores should be active in high-power mode.
- borissk 3y agoAnd yet millions of new phones sold in India, Africa, South America and Russia have only A53 cores.
- the_third_wave 3y agoI would not call the Redmi Note 5 (SD626) I've been using for the last 4 years "terribly slow", instead I call it "perfectly useable". This whole "laggy UI" thing people complain about is beyond me, the UI is GPU rendered and keeps up with most of what I throw at it. I don't expect a low-power device I charge every 3d day to perform like a mains-connected system.
- 29083011397778 3y ago> I would not call the Redmi Note 5... "terribly slow", instead I call it "perfectly useable". The software you use plays a rather large role in how the hardware performs. Some people here like to live on the OEM-designed happy path, where things tend to just work. That means using Google Apps for everything, an expectation that the latest video streaming social platforms will open quickly and not stutter, and scrolling the Google Play Store or Google Maps will be a fluid experience. Others may use simpler apps, or expect less of their phones. I'm in the latter category, and I suspect you are as well. While the BlackBerry KeyOne I use daily was panned by some six months after release in 2017 for being too slow, I instead killed off nearly everything else that would run in the background - including and specifically any Google frameworks and apps. Some software companies have made a point of taking any hardware gains for granted. Most people have new phones, with fast processors, so some companies will push devs to take shortcuts. I'm quietly indignant about that, though that rant is rather tangental to your original question about how some have such different experiences from yours.
- yukIttEft 3y agoWhen looking at die shots like https://i0.wp.com/chipsandcheese.com/wp-content/uploads/2023/05/a53_tegra_x1.jpg?ssl=1 https://i0.wp.com/chipsandcheese.com/wp-content/uploads/2023... I always wonder how people are able to label things. How does one figure out what part does what?
- curiousObject 3y agoIt’s easier to understand if you look at an analysis of a much older, less dense, die. Ken Shiriff is a superb source of these There are some visual clues. First, the chip pins are labeled in the spec so you can guess they’ll be close to relevant units, and also try to trace their connections throughout the die. Second, units like memory have an obvious regular structure because they are made from many identical micro-units Third, if you see, for example, 16 identical adjacent units you could guess this is something that could be dealing with data 16 bits at a time. That narrows it down There are numerous clues like those. You could also use tricks like using a thermal camera. What part gets hot when you do certain operations?
- samstave 3y agoOne of my professional regrets was when I worked at Intel in 1997, I had 30x42 plots of chip dies hanging on the wall in our lab... I wish I had taken some of them and framed them, they were beautiful.
- cebert 3y agoThat would be a nice to frame in an office.
- hotpotamus 3y agoThis reminds me that I meant to pick up some of the wafers sometime. I've seen failures/surplus/whatever for sale on eBay and other places and meant to get one to frame or display as they are impressive in their way.
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- causality0 3y ago"Efficient cores for low power tasks and performance cores for demanding applications" is a catchphrase I've seen hundreds of times but I've never once seen someone actually demonstrate it or test it, or even really explain how my phone decides which is which. Does WhatsApp run on an efficiency core most of the time but swap to a performance core when it's converting a video to send?
- jffry 3y agoI found this [1] which says: "Generally, when the game is in the foreground, persistent threads such as the game thread and render thread should run on the high-performance large cores, whereas other process and worker threads may be scheduled on smaller cores." There's also a Wikipedia article [2] which talks a little about scheduling. I imagine Android probably has more specific context it can use as hints to its scheduler about where a thread should be run. [1] https://developer.android.com/agi/sys-trace/threads-scheduling https://developer.android.com/agi/sys-trace/threads-scheduli... [2] https://en.wikipedia.org/wiki/ARM_big.LITTLE#Scheduling https://en.wikipedia.org/wiki/ARM_big.LITTLE#Scheduling
- masklinn 3y agohttps://eclecticlight.co/ https://eclecticlight.co/ Has multiple articles characterising the M1 (and M2) and how the MacOS scheduler uses it. I’m sure Android’s scheduled does things differently but it’s at least an idea of the sort of things which can happen. For macs (and I assume iOS) the basics are that background processes get scheduled on E cores exclusively, and higher priority processes get scheduled on P cores preferentially but may be scheduled on E cores if the P cores are at full occupancy.
- charcircuit 3y agoIt's mostly the Linux scheduler https://www.kernel.org/doc/html/latest/scheduler/sched-capacity.html https://www.kernel.org/doc/html/latest/scheduler/sched-capac... Android does set niceness for processes. See the THREAD_PRIORITY_* constants https://developer.android.com/reference/android/os/Process https://developer.android.com/reference/android/os/Process and it uses cgroups too. Process.THREAD_GROUP_* has some Android ones, but different vendors sometimes write their own to try and be clever to increase performance. https://source.android.com/docs/core/perf/cgroups https://source.android.com/docs/core/perf/cgroups
- deleted 3y ago[deleted]
- jpm_sd 3y agoThe A53 is very popular in automotive and embedded applications. I'm familiar with the iMX8 and the S32G but I'm sure there are others.
- adrian_b 3y agoIt is very popular only because almost all companies that are neither Chinese nor smartphone-oriented have failed to introduce any products with less obsolete ARM cores, for many, many years. NXP has begun to introduce products with Cortex-A55 only recently, but they should always be preferred for any new designs over the legacy products with Cortex-A53, because the Armv8.2-A ISA implemented by Cortex-A55 corrects some serious mistakes of the Cortex-A53 ISA, e.g. the lack of atomic read-modify-write memory accesses. The people who still choose Cortex-A53 for any new projects are typically clueless about the software implications of their choice. Unfortunately, there are only 3 companies that offer CPUs for automotive and embedded applications with non-obsolete ARM cores: NVIDIA, Qualcomm and MediaTek. All 3 demand an arm and a leg for their CPUs, so whenever the performance of a Cortex-A55 is not enough it is much cheaper to use Intel Atom CPUs than to use more recent ARM cores, e.g. Cortex-A78.
- jpm_sd 3y agoThis is a little harsh, upgrade cycles in these fields are very long. I'm working on a project right now where we are upgrading from iMX6 (quad A9) to iMX8 (quad A53).
- photochemsyn 3y agoThis is an area where RISC-V could be come a major competitor, e.g. SiFive has a https://www.eenewseurope.com/en/sifive-aims-for-arm-with-high-performance-risc-v-vector-cores/ https://www.eenewseurope.com/en/sifive-aims-for-arm-with-hig... > "The Performance P670 and P470 RISC-V cores are designed to take on ARM’s Cortex A53 and A55 cores, Drew Barbier, senior director of product management at SiFive tells eeNews Europe." A compare-and-contrast article would make for good reading.
- justahuman74 3y agoI'd love to see a chart with all the licenseable arm and riscv cores compared
- manuelabeledo 3y agoWhat I see there is that SiFive is, at the very least, five years behind the mid range of ARM CPUs, not only in performance, but also regarding the toolchain. At a similar cost, what’s the real advantage of migrating the current catalog of wearables or IoT products, to RISC-V? There’s a proven and tested platform, widely used in the industry, and the alternative is still trying to catch up.
- sosodev 3y agoIt's interesting that the author used a photo of the Tegra X1 here. My understanding is that the Nintendo Switch (most widely distributed Tegra X1?) never or very rarely uses its A53 cores.
- sillywalk 3y agoI wish that ARM's naming convention was less.. complicated. It's like USB.
- rektide 3y agoPretty wild to me that the Cortex A53 is a decade old & barely modified in it's newer forms. It's so hard to imagine so many years & a microarchitecture remaining so unchanging. By compare Intel's been making small but OK revs to the Atom cores. And the new E-core on the new n100 replacement is monstrously faster, yet still small. A potential core-m moment for Intel, a great small chip that expands.
- snvzz 3y ago>It's so hard to imagine so many years & a microarchitecture remaining so unchanging. It's a shame, because it was the best design from ARM; they're now focusing on Cortex-A7x and Cortex-X, which aren't anywhere as power efficient[0]. Meanwhile, their revised Cortex-A57 has been surpassed in performance/power/area by several RISC-V microarchitectures, such as SiFive's U74[1], used in the VisionFive2 and Star64, or even the open source XuanTie C910[2][3]. 0. https://youtu.be/s0ukXDnWlTY?t=790 https://youtu.be/s0ukXDnWlTY?t=790 1. https://www.sifive.com/cores/u74 https://www.sifive.com/cores/u74 2. https://xrvm.com/cpu-details?id=4056743610438262784 https://xrvm.com/cpu-details?id=4056743610438262784 3. https://github.com/T-head-Semi/openc910 https://github.com/T-head-Semi/openc910
- bullen 3y agoI still use original Raspberry 2's (A53) in my server clusters, they are the lowest power devices that can saturate (good) SD cards on random writes/reads and still have performance left to serve calculations. A72 in Raspberry 4 is really the pinnacle low power CPU performance if you count $ and compatibility (linux <-> GPU). ~3x can saturate symmetric 1Gb/s with advanced computation and still have calculations left. You can buy neither, we'll see if the 4 ever comes back. The only thing I'm 100% of is that the 5 will have some drawback compared to both the 2 and the 4. I can concur the peak of A55; the 5W TDP 22nm RK3566 in my RG353M is mind boggling! HL1 at 60 FPS and soon HL 2 at 30 FPS. But Risc-V is not progressing with linux, mainly GPU drivers and integration is the problem. Historically the Chinese boards never got any attention and unfortunately you cannot depend on attention happening this time either. Partly because now companies across the board(ers) are hiding kernel configs again. And "board support packages" are slow to be mainlined if ever.
- drudru 3y agoNo mention of the Raspberry Pi use of the processor core is a bit strange given the comprehensive analysis.