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Arm's Cortex X925: Reaching Desktop Performance
- pdpi 8mo agoKind of weird to see an article about high-performance ARM cores without a single reference to Apple or how this hardware compares to M4 or M5 cores.
- SG- 8mo agoSame, I wish Chips and Cheese would compare some of these cores to Apple Silicon, especially in this case where they're talking about another ARM core. A few years ago they were writing articles about Apple Silicon.
- ezst 8mo agoThat would only matter (to me, at least) if those Apple chips were propping up an open platform that suits my needs. As things stand today, procuring an M chip represents a commitment to the Apple software ecosystem, which Apple made abundantly clear doesn't optimize for user needs. Those marginally faster CPU cycles happen on a time scale that anyway can't offset the wasted time fighting MacOS and re-building decades-long muscle memory, so thanks but no thanks.
- pdpi 8mo agoSure. Insofar as Apple Silicon beats these things, "I'll take less powerful hardware if it means I'm not stuck with the Apple ecosystem" is a perfectly reasonable tradeoff to make. Two things, though. First, I don't like making blind tradeoffs. If what I need (for whatever reason) is a really beefy ARM CPU, I'd like to know what the "Apple-less tax" costs me (if anything!) Second, the status quo is that Apple Silicon is the undisputed king of ARM CPU performance, so it's the obvious benchmark to compare this thing against. Providing that context is just basic journalistic practice, even if just to say "but it's irrelevant because we can't use the hardware without the software".
- amelius 8mo agoLet's say my company makes systems for in-flight entertainment, with content from my company. I am looking for a CPU. I don't want to confront my users with "Please enter your Apple ID" or any other unexpected messages that I have no control over. Is Apple M series an option for me?
- rick_dalton 8mo agoThe X925 core is used in chips like the gb10 for the nvidia dgx spark. So it is relevant to compare to apple silicon performance imo. The mac studio is pretty much a competitor to it.
- ghosty141 8mo agoWhy should it be? All he is saying: We currently have products in a similar product category (arm based desktop computers) that are widely used and have known benchmark scores (and general reviews) and it would make sense if I publish a new cpu for the same product category ("Reaching Desktop Performance" implies that) that I'd compare it to the known alternatives. In the end you can just run Asahi on your macbook, the OS is not that relevant here. A comparison to macbooks running Asahi Linux would be fine.
- amelius 8mo agoBut why would an article address _their_ specific usecase?
- buran77 8mo ago> But why would an article address _their_ specific usecase? amelius, if anyone had specific requirements, it was you with your "systems for in-flight entertainment". OP asked a very reasonable question for a very generic comparison to the 800-pound gorilla in the consumer CPU world in general, and ARM CPU world in particular. If the article can reference AMD's Zen 5 cores and Intel's Lion/Sunny Cove, they could have made at least a brief reference to M-series CPUs. As a reader and potential buyer of any of them, I find it would have been a very useful comparison.
- flembat 8mo agoWhen purchasing any ARM based computer a key question for me, is how many of those can I purchase for the cost of a Mac mini, and how many Mac mini can I purchase for the cost of that, and does that have working drivers...
- ezst 8mo agoAnd the answer there may absolutely be "none", which equates to doing away with ARM, which is totally fine. I don't have a horse in the x86 vs ARM race, especially since it's pretty clear that performance per watt stands within a narrow margin across arches on recent nodes.
- spiderfarmer 8mo ago> represents a commitment to the Apple software ecosystem I don't see how that's holding you back from using these tools for your work anymore than using a Makita power tool with LXT battery pack.
- ezst 8mo agoPretty simply because I don't want to use MacOS, its terrible window management, quirks and idiosyncrasies. In your comparison, my gripe wouldn't be about the hassle of finding 3rd-party compatible batteries, but about the daily handling of the Makita while knowing the DeWalt to be more ergonomic and better suited to my needs.
- BlobberSnobber 8mo agoAs someone who uses Linux, macOS and Windows interchangeably, I'm curious to know what you're using. I learned to live with macOS, but I also like and use Gnome, which many Linux-only people hate. I tried most WMs on Linux, like Hyprland, Sway, i3, but none ever felt worth the config hassle when compared to the sane defaults of Gnome.
- lproven 8mo ago> the sane defaults of Gnome. I have to admit that when I read this, my eyebrows went up so far that my hat moved.
- BlobberSnobber 8mo agoI know what you mean, but Gnome was the DE that clicked the most for me (after I gave it a real try). I liked Gnome 2 and then 3 made me switch to KDE, then switched back. So I was actually completely wrong and, while writing this comment, I remembered what a pain it was to learn Gnome back then lol
- spiderfarmer 8mo agoThat’s not what a commitment is though. If I use a Makita because the battery life and resale value is twice that of a DeWalt, I wouldn’t say Makita is asking for a commitment to their ergonomics.
- upcoming-sesame 8mo agostill matters as a benchmark imo
- tucnak 8mo agoFWIW, Apple Virtualization framework is fantastic, and Rosetta 2 is unmatched on other Arm desktops where QEMU is required. For example, you can get Vivado working on Debian guest, macOS host trivially like that.
- ezst 8mo agohttps://www.macrumors.com/2025/06/10/apple-to-phase-out-rosetta-2/ https://www.macrumors.com/2025/06/10/apple-to-phase-out-rose...
- Orygin 8mo agoThey are not phasing it out for virtualization.
- p_ing 8mo agoOnly reference I can find is: "Starting with computers using macOS 28, Rosetta functionality will be available only for certain older, unmaintained games that rely on Intel-based frameworks." https://support.apple.com/en-us/102527 https://support.apple.com/en-us/102527 And "Beyond this timeframe, we will keep a subset of Rosetta functionality aimed at supporting older unmaintained gaming titles, that rely on Intel-based frameworks." https://developer.apple.com/documentation/apple-silicon/about-the-rosetta-translation-environment/ https://developer.apple.com/documentation/apple-silicon/abou...
- drzaiusx11 8mo agoBeen using Colima to run mixed architecture container stacks in docker compose on my M3 Mac and the machine barely blinks. I get a full day running a dozen containers on a single battery charge. Colima is backed by qemu, not Rosetta, so if Rosetta disappeared tomorrow I don't think I'd notice. I'm sure it's "better" but when the competition is "good enough" it doesn't really matter.
- renewiltord 8mo agoLast time I tried, getting Linux working on Apple Silicon actually worked better than on Qualcomm ARM machine (which only support strange Windows).
- drzaiusx11 8mo agoAsahi Linux is fantastic these days, but as with most linuxes on laptops the power management / battery life is the worst part. If treating a laptop like a portable desktop is ok for your use case you'd be plenty happy. If you're far away from an outlet for too long however, you'll find it lacking. At least that's my experience. It's possible they eventually figure that out too...
- synergy20 8mo agototally true. for me it's unless until those apple hardware can run linux first-class, till then it's irrelevant. sad to say this but macos sucks.
- truelinux1 8mo agoThis echoed my thoughts exactly - Linux only.
- amelius 8mo agoApple does not produce general purpose computing parts. This is an industry blog, not a consumer oriented blog.
- charcircuit 8mo agoM4 and M5 are literally general purpose computing parts. Apple literally owns the most profitable general purpose computing platform with the iPhone.
- senko 8mo agoPerhaps this was worded poorly, but the parent is referring to inability to source these processors from Apple and use them in other (non-Apple devices). As in, they don't sell you the parts, they only sell you the entire product. If you don't want the entire package, the processors alone are irrelevant.
- llm_nerd 8mo agoNone of us can buy or make an X925 in isolation. We can't get one and stick it in our motherboard. It has literally zero relevance to the desktop space. You can buy a DGX Spark and use it, just like you can buy a Mac Mini. The tested machine is an nvidia GB10 which nvidia makes and sells as a whole unit and various vendors stick it in different devices to try to differentiate (although in the end they're all basically identical). And yes, it is extremely weird for it to never mention the Apple chip, which has a little something to do with who they thank for lending them the device. The arbitrary claims for why they ignored the enormous, class-leading ARM processor in the space is not convincing. I mean, the other claim that this is an "industry blog" and not a "consumer blog" was equally silly. It's basically for curious hobbyists. Zero industry insiders follow this to see about the core in the GB10. It's basically Anandtech.
- layer8 8mo agoThe iPhone is anything but a general purpose computing platform. Apple actively prevents many purposes.
- atwrk 8mo agoThose are of almost zero use for people wishing to run Linux etc. Yes, Asahi exists, and props to the developers, but I don't think I'm alone in being unwilling to buy hardware from a manufacturer who obviously is not interested in supporting open operating systems
- promiseofbeans 8mo agoI mean… Apple went out of their way to build a GUI OS picker that supports custom names and icons into their boot loader. So they don’t actively help (or event make it easy by providing clear docs), but they do still do enough to enable really motivated people
- DeathArrow 8mo ago>Kind of weird to see an article about high-performance ARM cores without a single reference to Apple And Qualcomm.
- hrmtst93837 8mo ago[flagged]
- dgacmu 8mo agoMost of your comment history reads like LLM generated trite comments. Are you human?
- hrmtst93837 8mo ago[flagged]
- llm_nerd 8mo agoThe core they're talking about was released about two years ago. nvidia stuck it on their grace blackwell (e.g. DGX Spark) as basically a coordinator on the system. Anyway, here it is in GB10 form- https://browser.geekbench.com/v6/cpu/14078585 https://browser.geekbench.com/v6/cpu/14078585 And here is a comparable M5 in a laptop- https://browser.geekbench.com/macs/macbook-pro-14-inch-2025 https://browser.geekbench.com/macs/macbook-pro-14-inch-2025 M5 has about a 32% per core advantage, though the DGX obviously has a much richer power budget so they tossed in 10 high performance cores and 10 efficiency cores (versus the 4 performance and 6 efficiency in the latter). Given the 10/10 vs 4/6 core layouts I would expect the former to massively trounce the latter on multicore, while it only marginally does. Samsung used the same X925 core in their Exynos 2500 that they use on a flip phone. Mediatek put it in a couple of their chips as well. "Reaching desktop" is always such a weird criteria though. It's kind of a meaningless bar.
- drzaiusx11 8mo agoAfaict the "desktop" target is meaningless these days. Desktops aren't really a thing anymore in the general sense are they? Only folks I know still hanging on to desktop hardware are gamers and even those I see going by the wayside with external video cards becoming more reliable. "Daily driver" is probably a better term, but everyone's daily usage patterns will vary. I could do my day job with a VT100 emulator on a phone for example.
- deleted 8mo ago[deleted]
- wmf 8mo agoThe "desktop" market includes laptops but excludes servers, phones, tablets, etc.
- ThrowawayR2 8mo agoThere's a zillion office workers that have low cost mini PCs from the big OEMs on their desk. After all, all those off-lease mini PCs on eBay that are so beloved by home lab enthusiasts have to come from somewhere.
- KingOfCoders 8mo agoPerhaps you're not the target audience of the article.
- cubefox 8mo agoKind of weird that you pick Apple CPU cores when Qualcomm cores would be a far more appropriate comparison.
- Numerlor 8mo agoApple doesn't expose the kind of introspection necessary to compare with the data the article is about. Any mention would just be about Apple's chips existing and being better
- geerlingguy 8mo agoChips and Cheese focuses on architecture and chip design, and I think a lot of the tooling is less refined on macOS, so the comparison graphs can't quite get the same depth on Apple's chips. That's just a guess. But I did some comparisons when I tested the same Dell GB10 hardware late last year: https://www.jeffgeerling.com/blog/2025/dells-version-dgx-spark-fixes-pain-points/ https://www.jeffgeerling.com/blog/2025/dells-version-dgx-spa...
- GeekyBear 8mo agoIt does make me miss the deep dives for new core designs from Anandtech. Running the SPEC benchmark interger and floating piitnt suites takes all day, but it's hard to game a benchmark with that much depth. It's a shame that nobody has been willing to offer that level of detail.
- hank808 8mo agoThey are talking specifically about ARM cores designed by and licensable from ARM Holdings (the company), not other designs that don't use ARM's designs (like the Apple silicon).
- close04 8mo agoThey repeatedly compare to Intel and AMD cores though, which are x86. If they’re worth a mention, then so are some of the other ARM consumer desktop chips on the market regardless of who designed them. Apple was one of the closest ARM chips they could have compared to. Your “specifically ARM cores designed by and licensable from ARM Holdings” argument doesn’t hold any water.
- ddtaylor 8mo agoCan't zoom any of the content on mobile so most of the charts are unreadable.
- GaggiX 8mo agoBrowsers usually have an accessibility option to force the ability to zoom on all websites.
- ddtaylor 8mo agoThis website has those features disabled in Chrome or Brave. Apparently the Zoom option will only appear for "sites that support this feature". This is because they set this header in the meta tags: user-scalable=0
- sfdlkj3jk342a 8mo agoZoom works fine with Firefox on Android.
- dinglo 8mo agoIf ARM starts dominating in desktop and laptop spaces with a quite different set of applications, might we start seeing more software bugs around race conditions? Caused by developers writing software with X86 in mind, with its differing constraints on memory ordering.
- ivolimmen 8mo agoIf you go around your OS yes that could be the case but you can already have issues using the application from machine to machine with the same OS having different amounts of RAM and different CPU's. But I am not an expert in these matters.
- dd_xplore 8mo agoThe major issue is these days most software is electron based or a webapp. I miss the days of 98/XP, where you'd find tons of desktop software. A PC actually felt something that had a purpose. Even if you spin up a XP/98(especially 98/2000 VM) now, you'd see the entire OS feels something that you can spend some time on. Nowadays most PCs feel like a random terminal where I open the browser and do some basic work(except for gaming ofcourse). I really hate the UX of win 11 , even 10 isn't much better compared to XP. I really hope we go back to that old era.
- rbanffy 8mo ago> Nowadays most PCs feel like a random terminal It's a fun perception. For the longest time, all the "serious" computers were used through networks and terminals and didn't even come with any ability to connect a monitor or a keyboard (although a serial terminal would work as the system console). I used to joke (usually looking at Unisys Windows-based big servers), if the computer had VGA and PS/2 ports, it wasn't a computer, but a toy. Those Unisys servers weren't toys, but you could run Pinball and Minesweeper directly on them, which kind of said otherwise. I think we got used to such levels of platform bloat that we don't care if the UI toolkit these days is bigger than the entire operating system that runs 95% of the world's payment transactions.
- pjmlp 8mo ago
- Incipient 8mo agoWithout being a cpu geek, a lot of the branch prediction details go over my head, however generally a good review. I liked the detail of performance on more complex workloads where IPC can get muddy when you need more instructions. I feel these days however, for any comparison of performance, power envelope needs to be included (I realise this is dependent on the final chip)
- adrian_b 8mo agoARM Cortex-X925 achieves indeed a very good IPC, but it has competitive performance only in general-purpose applications that cannot benefit from using array operations (i.e. the vector instructions and registers). The results shown in the parent article for the integer tests of SPEC CPU2017 are probably representative for Cortex-X925 when running this kind of applications. While the parent article shows AMD Zen 5 having significantly better results in floating-point SPEC CPU2017, these benchmark results are still misleading, because in properly optimized for AVX-512 applications the difference between Zen 5 and Cortex-X925 would be much greater. I have no idea how SPEC has been compiled by the author of the article, but the floating-point results are not consistent with programs optimized for Zen 5. One disadvantage of Cortex-X925 is having narrower vector instructions and registers, which requires more instructions for the same task and it is only partially compensated by the fact that Cortex-X925 can execute up to 6 128-bit instructions per clock cycle (vs. up to 4 vector instructions per clock cycle for Intel/AMD, but which are wider, 256-bit for Intel and up to 512-bit for Zen 5). This has been shown in the parent article. The second disadvantage of Cortex-X925 is that it has an unbalanced microarchitecture for vector operations. For decades most CPUs with good vector performance had an equal throughput for fused multiply-add operations and for loads from the L1 cache memory. This is required to ensure that the execution units are fed all the time with operands in many applications. However, Cortex-X925 can do at most 4 loads, while it can do 6 FMAs. Because of this lower load throughput Cortex-X925 can reach the maximum FMA throughput only much less frequently than the AMD or Intel CPUs. This is compounded by the fact that achieving better FMA to load ratios requires more storage space in the architectural vector registers, and Cortex-X925 is also disadvantaged for this, by having 4-time smaller vector registers than Zen 5.
- 8mo ago
- xarope 8mo agoI can't seem to find any power draw or efficiency figures (e.g. <perf>/watts). Only found this which talks about performance-per-area (PPA) and performance-per-clock ()I assume cycle) (PPC): https://www.reddit.com/r/hardware/comments/1gvo28c/latest_arm_cpu_cores_compared_performanceperarea/ https://www.reddit.com/r/hardware/comments/1gvo28c/latest_ar...
- sylware 8mo agoBut with hardware IP locks like x86_64. Better favor as much as possible RISC-V implementations. But, I don't know if there are already good modern-desktop-grade RISC-V implementations (in the US, Sifive is moving fast as far as I know)... and the hard part: accessing the latest and greatest silicon process of TMSC, aka ~5GHz. Those markets are completely saturated, namely at best, it will be very slow unless something big does happen: for instance AMD adapts its best micro-architecture to RISC-V (ISA decoding mostly), etc. And if valve start to distribute a client with a strong RISC-V game compilation framework...
- DeathArrow 8mo agoThis is kind of a solution in search for a problem. RISC-V will grow only if people find some value in it. If it solves their actual problems in ways that other architectures can't.
- hylaride 8mo agoYeah, the primary reason RISC-V exists is political (the desire to have an "open source" CPU architecture). As noble as that may be, it's not enough to get people or companies to use (or even manufacture!) it. It'll either be economical (costs) and/or performance (including efficiency) that drives people. It took ARM decades to get to where it is, and that involved a long stint in low-margin niche applications like embedded or appliances where x86 was poorly suited due to head and power consumption.
- cmrdporcupine 8mo agoI don't think that's the primary reason there's momentum there. The reason is to avoid ARM licensing fees and IP usage restrictions. I think you'll see ever more accelerating RISC-V adoption in China if the United States continues on its "cold war" style mentality about relations with them. That said we're a long long way from Actually Existing RISC-V being at performance parity with ARM64, let alone x86.
- 8mo ago
- Supersaiyan_IV 8mo agoAnother good read is about ARM's SVE2 extensions: https://gist.github.com/zingaburga/805669eb891c820bd220418ee3f0d6bd#file-sve2-md https://gist.github.com/zingaburga/805669eb891c820bd220418ee... It has some interesting conclusions, such as that it covers certain AVX512 gaps: "AVX512 plugs many of the holes that SSE had, whilst SVE2 adds more complex operations (such as histogramming and bit permutation), and even introduces new ‘gaps’ (such as 32/64-bit element only COMPACT, no general vector byte left-shift, non-universal predication etc)." And also that rusty x86 developers might face skill issues: "Depending on your application, writing code for SVE2 can bring about new challenges. In particular, tailoring fixed-width problems and swizzling data around vectors may become much more difficult when the length is unknown."
- voidmain0001 8mo agoAlready usurped by Arm C1 Ultra. https://www.androidauthority.com/arm-c1-cpu-mali-g1-gpu-deep-dive-3595933/ https://www.androidauthority.com/arm-c1-cpu-mali-g1-gpu-deep...
- adgjlsfhk1 8mo agoThe C1 Ultra looks really powerful. 128 kb L1D cache on it's own is a ~10% IPC improvement that should let it pull firmly ahead of the x86 competition which is very stuck at 32kb due to the legacy 4k page size.
- joha4270 8mo agoI'm sorry, I'm clearly missing something but why would page size impact L1 cache size?
- adgjlsfhk1 8mo agoThis the the most cursed part of modern cpu design, but the TLDR is that programs use virtual addresses while CPUs use physical addresses which means that CPU caches need to include the translation from virtual to physical adress. The problem is that for L1 cache, the latency requirement of 3-4 cycles is too strict to first do a TLB lookup and then an L1 cache lookup, so the L1 can only be keyed on the bits of ram which are identical between physical and virtual addresses. With a 4k page size, you only have 6 bits between the size of your cache line (64 bytes) and the size of your page, which means that at an 8 way associative L1D, you only get 64 buckets*64 bytes/bucket=32 kbits of L1 cache. If you want to increase that while keeping the 4k page size, you need to up the associativity, but that has massive power draw and area costs, which is why on x86, L1D on x86 hasn't increased since core 2 duo in 2006.
- rslashuser 8mo agoNice HN explanation! One hopes we will not be living with 4kb pages forever, and perhaps L1 performance will be one more reason.
- rayiner 8mo agoARM designs are effectively paper launches. You get these press releases saying the new ARM matches Apple and AMD, but its years before you can buy a product with it. Google Pixels that came out in the fall are still on the X4, which was introduced in 2023. At this rate, Pixel 11 will launch with X925, which is an Apple A17/M3 tier core, when Apple is on the A20: https://wccftech.com/apple-a20-and-a20-pro-all-technological-advancements-arriving-to-the-2nm-chipsets https://wccftech.com/apple-a20-and-a20-pro-all-technological.... Outsourcing the core design creates a major lag in product availability.
- ac29 8mo ago> ARM designs are effectively paper launches. You get these press releases saying the new ARM matches Apple and AMD, but its years before you can buy a product with it. This is an article testing shipping hardware you can buy today.
- Symmetry 8mo agoYeah, the paper launch OP is talking about happened way back in May 2024.
- aseipp 8mo agoI feel like that was much more true in the past but the X925 was only spec'd 18 months ago(?) and you can buy it today (I'm using one since October). Intel and AMD also give lots of advance notice on new designs well ahead of anything you can buy. ARM is also moving towards providing completely integrated solutions, so customers like Samsung don't have to take only CPU core and fill in the blanks themselves. They'll probably only get better at shipping complete solutions faster. Honestly, Apple is the strange one because they never discuss CPUs until they are available to buy in a product; they don't need to bother.
- hajile 8mo agoThis core was released in the MediaTek 9400 in October 2024 some 16 months ago. The successor of x925 is C1 Ultra and even that was released 6 months ago in September 2025 with the MediaTek 9500 and GeekerWan even has a phone review they did with that chip last year.
- throwaway85825 8mo agoWhy would I care about desktop performance without the PC desktop ecosystem where everything 'just works'? Universal ARM linux distros aren't supported by anything.
- guerrilla 8mo agoWhy would you not be able to build a PC around it? That's what you do with PowerPC.
- exabrial 8mo agoHoping someday we can get ARM System76 laptops that meet Apple M* chip performance.
- jadbox 8mo agoFor most, it doesn't need to 'meet' Apple's performance. It just needs to be competitive to general hardware of around the -the same price point- category. This is the same problematic statement I hear that a ~$1500 PC laptop just isn't as good as a ~$3000 macbook.
- megous 8mo agoBTW, does anyone have some pointers to where one can find an oldish in-order Cortex-A core (like A53) in verilog RTL form? I know ARM must give this out to companies that implement ARM based SoCs for eg. purpose of validation on FPGA. So far I've only found various M cores online. It would be fun to have something to experiment with on a cheapish FPGA like Kintex XC7-K480T, that may have enough resources for some in-order A core, and can be had for $50 or so.
- adgjlsfhk1 8mo agoYou're going to have a much better time finding RiscV cores.
- megous 8mo agoYeah, I don't need help with that one. :)
- wmf 8mo agoArm lawyers have the RTL locked down tight. If you find it, it means you are already dead.
- megous 8mo agoLOL