8 ms·
In Defense of RAM
- brucethemoose2 3y agoYes, all this... Except for the advocation of upgradable RAM. Embedded RAM, like or not, is the future of CPUs unless you want memory performance/power efficiency to freeze near current levels. Doubly so for graphics heavy SoCs like the M series. But Apple motherboards should absolutely be swappable, Framework style. This would not be a huge technical compromise like swappable RAM, or a design compromise like a socketed M CPU. And maybe we can get CXL "overflow" memory slots in laptops where performance is slow, but still 100x better than swap on SSDs.
- RamRodification 3y ago> Embedded RAM, like or not, is the future of CPUs unless you want memory performance/power efficiency to freeze near current levels Why is that?
- bryanlarsen 3y agoM2 pro/max/ultra bandwidth is 200/400/800 GBps. Ryzen dual channel bandwidth is 100GBps. EPYC 8 channel bandwidth is well under 400GBps.
- brucethemoose2 3y agoAnd more importantly, M2's energy/bit is pretty low.
- matja 3y ago* Shared bandwidth between CPU and GPU - as soon as you use up one, you're bottlenecking the other. * No M2 memory benchmark I've seen gets above ~250GB/s once cache effects are exceeded. * Random access latency is >~110ns which is no improvement over even mid-range DDR4 designs from 5 years ago. TL;DR: It's about cost
- brucethemoose2 3y agoBecause the signal integrity across the pins and traces becomes a serious bottleneck. SODIMMs are already "past" the limit, requiring 1.35V for modest DDR5 speeds at terrible timings, hence vendors are trying to migrate to this: https://www.anandtech.com/show/21069/modular-lpddr-becomes-a-reality-samsung-introduces-lpcamm-memory-modules https://www.anandtech.com/show/21069/modular-lpddr-becomes-a... I suspect regular desktop/server DIMMs are getting close to their limit as well Essentially, the closer the RAM sits to the CPU, the faster/lower latency/lower power it gets. This is especially important in graphics heavy chips, where the wide, high frequency busses can eat loads of power. In fact, I wouldn't be surprised if Apple transitions to something "new" like a newer generation of Samsung's Wide I/O if they can get memory vendors to produce it in bulk.
- DannyBee 3y agoIt's remarkably difficult to maintain signal integrity/etc if it's not very close to the CPU at the signal rates they are getting to. This is already a serious problem. For places where you are willing to give up power efficiency, or latency, or both, this is not as big a deal - this is why you see CXL/etc. But for a laptop, where people want power efficiency, latency, etc, this is a serious issue.
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- sliken 3y agoLets compare. The m3 max has up to 128GB of ram, 400GB/sec bandwidth, and uses that memory for both CPU and GPU. It fits in thin (under an inch thick) laptops and is efficient enough to have great battery life on the order of 10-20 hours depending on use cases. So efficient that performance is identical when running on battery or wall power, unlike many of it's competitors. The power savings is even more impressive once you consider you don't need a discrete GPU for many use cases. The AMD Epyc has 12 channels of DDR5-4800 and manages 460GB/sec. It's a physically large chip, can handle a ton of ram, but also uses a ton of power. You can fit a crippled version (without all the memory channels) on a micro atx motherboard that's several inches thick. Normally you'd need an ATX, EATX, or rack mount motherboard. It needs several 100 watts for just the socket, not to mention the numerous dimms (12 minimum for 12 memory channels). It's the kind of thing you see in a data center, after you put ear protection on. If you compare the M3 max, which fits in a laptop or small desktop, to Intel and AMD competition that fits in a thin laptop you end up with 1/4th the memory bandwidth. The competition either matches the power use and is much slower, or is as fast or faster at a huge power penalty. AMD and Intel laptops need discrete GPUs to compete and often require wall power to run at full speed. All in all the M3 max is an impressive chip, fast, and very efficient. But part of that is the soldered in dimms that allow for great bandwidth and low power use.
- brucethemoose2 3y agoThis is Apples and oranges. A better AMD comparison is Van Gogh (the Steam Deck chip) to the base M1, and on paper they are very similar. The M1 is just a more "premium" version of the budget AMD chip. AMD could make a good M3 competitor (and maybe even improve on it by tiling the memory controller/cache like the 7900), but... There is just no market for it. Windows OEMs dont want a big expensive SoC, they want a cheap CPU to hang a power hungry graphics card off of. Hence the successor to Van Gogh was canceled because no one wanted it.
- sliken 3y agoAMD/Intel iGPUs stink, mostly because the standard 128 bit wide memory system from the lowest end Intel/AMD laptop/desktop chips to the high end like the Ryzen 9 7950x have the same memory bandwidth. AMD even makes better memory systems for the XboxX and PS5, which run games great. For years gamers drifted from gaming desktops to consoles because GPUs were insanely priced or unavailable. However, finally, many years after the GPU shortage there's GASP going to be a laptop/desktop chip with iGPU with more than a 128 bit wide memory interface. The AMD Strix Halo. I hope it does well, it's roughly similar to the M2 Pro. Still half a M2 Max or 1/4th a M2 ultra.
- linmob 3y ago8 GB RAM is not even enough to do Pro-level web-browsing, so I do agree, this new 14" Macbook Pro is a joke - and let's not forget that swapping can't be good for the storage you can't replace. I don't think upgradable RAM is coming back to Apple Silicon Macs. Upgradable storage, maybe; and there might be a use for standard RAM as a faster Swap, e.g., in a Mac Pro, to have 256 GB of super fast unified RAM and additional TBs of DIMMs for workloads that need that. Nitpick: Something is off with the timeline of M2 Pro Macbook Pro ownership mentioned in the article ("Two years ago, I got a 14” MacBook Pro with an M2 Pro processor and 16 GB of RAM.") M2 Pro Macbook Pro were only introduced in January 2023.
- throwaway49594 3y agoA 'pro' machine should probably have more RAM than a Raspberry Pi.
- linmob 3y agoTrue, since as long as it's a Raspberry Pi, not a Raspberry Pro. ;-)
- rascul 3y agoWhat is Pro-level web-browsing?
- superkuh 3y agoApple selling 8GB of RAM laptops is both wonderful for tech support people and horrible. Pretty much every non-technical person I know who bought an 8GB M* device has run into problems. But pretty much every technical person I know says they have no problems. I wonder what the difference is? Regardless, I get lots of calls for help with M* macs re: running out of ram when running Adobe Creative Suite + darkroom/lightroom, etc, or the normal mac problems of having no storage (ie, 256GB/512GB) and the octopus of external drives and dongles not working right because externals/dongles are incredibly fragile and problem prone. It's horrible because there's actually no "fix" I can offer these normal people who made the mistake of buying an unupgradable 8GB computer.
- seanw444 3y ago> I wonder what the difference is? Technical people understand the limitations, and work within them, and aren't disappointed when they know they're hitting the upper limit. Normies want a cheap laptop, but don't understand why their bottom-tier Apple laptop can't run everything at once.
- unilynx 3y agoExactly this. I enjoyed the 2015 MacBook for its size and weight and still having usability, and find it a pity that there wasn't really ever a followup to it. It makes the airs look bulky. But most users are probably disappointed and expected more from it, so I understand why they weren't able to continue that line
- xkcd-sucks 3y agoI got an M1 macbook pro from work, who through several layers of bureaucracy got me a 16 inch instead of the requested 14 inch, and with 8GB RAM instead of the requested 16GB. For running a huge data processing platform in containers, BI tools, powerpoint and excel, etc. I would describe it as "no unexpected problems that aren't natural consequences of choices": Apple's memory and swap management is actually shockingly good under the circumstances, it does thrash the SSD a bunch, and it locks up hard if put to sleep under heavy memory pressure. One mitigation is just leaving it awake overnight before any critical demos, etc. EDIT: I was wrong; it is a 16GB model, 32GB was the ask, performance is as described, it feels smaller; 8GB would probably be totally unusable.
- jewel 3y agoMemory compression (via zswap) has made a big difference for me, on Linux, when on a constrained device. It makes a lot of sense for desktop workloads where most time is spent waiting for user input. For me it was a lot faster than swapping to disk, although with NVME drives that may no longer be the case. I thought I had read when the M1 came out that they had memory compression turned on by default but I'm not an Apple user.
- zamadatix 3y agoMemory compression has been enabled macOS since Mavericks/2013. Windows, Android/ChromeOS, and a lot of big name Linux Distros (like Fedora/Ubuntu) all default to some form of memory compression support out of the box as well IIRC.
- kstrauser 3y agoIt's enabled on my 2023 MacBook Air, or at least Activity Monitor shows an amount of compressed memory.
- zamadatix 3y agoI can see the argument the Pro really should have 16 GB base. It's not about whether 8 GB can fit anyone's use case reasonably (of course it can) or whether it's not enough to fit other's use cases (of course it isn't) but whether more people are getting the 8 GB version in error or because it was actually a good fit. An 8 GB Air is more defensible though, even if I wouldn't get it myself. In regards to upgradeable RAM I'd rather not see it in the laptops. Too much power and efficiency left on the table for something with an overall audience who will rarely utilize the ability to swap it anyways. I do like the swapability in things targeted at more niche audiences though. I think Intel's approach with on chip memory in some of the new Xeons is interesting, you can use it as RAM or as a cache for your actual RAM should you need more than can be put on chip. Could fit well with the Studio/Pro line audience.
- brucethemoose2 3y ago> I think Intel's approach with on chip memory in some of the new Xeons is interesting Thing is, HBM is a questionable fit for laptops because its extremely expensive, and pretty high power. What Apple does is essentially what smartphones have been using for awhile, just scaled up. Its a good idea, and AMD/Intel can do it or even improve on it if they want.
- dragontamer 3y agoThe opposite. HBM is low power actually. Very very low power at very low clock-rates. The issue is that HBM needs like 4096 pins per connection or something absurd like that. So the only way to run HBM is through die-stacking (where the 4096 pins all lineup and the chip-manufacturer solders them together in a cleanroom). HBM uses incredibly low amounts of power as a protocol. But then it jacks up the pin-count and runs thousands of the protocol in parallel to increase effective bandwidths. In any case, you won't be able to physically route HBM on a PCB. The trace count alone makes it impossible.
- brucethemoose2 3y agoDoes it have, say, power saving modes at idle like DDR5 does? And coming iterations of HBM seem to be cranking up the clock rate
- wnorris 3y agoWhat gets me is how Apple markets the improvements in the M series processor. They iterate on these on a yearly basis, yet do not upgrade base model RAM for near a decade.RAM is quite often the limiting factor for current computer longevity. This is especially true of Apple computers as RAM is non-upgradable. Apple at a minimum should create a cadence of RAM upgrades to coincide with processor upgrades to at least some extent. Otherwise they are selling base model computers that are going to require most users to replace sooner. Conflicts with Apple's environmental efforts.
- foobarchu 3y ago>RAM is quite often the limiting factor for current computer longevity I think this is an interesting point, because my own experience completely disagrees. I feel like consumer laptop RAM has been stagnated at 8gb or 16gb for about decade now, which is insane as someone who grew up during the turn of the millennium when it was doubling yearly. Among myself and people I know, the biggest factors for getting a new machine are usually (in order) battery life/consumption, physical condition, storage, and OS support for the hardware. I haven't heard someone say they need a computer with more RAM unless they started using it for new purposes they didn't before (someone getting into video editing, data analysis, etc).
- goalieca 3y agoApple has put a ton of effort into optimizing software to squeeze more out of less ram. They also have operating system level features like compressed ram. The whole implied argument about hardware longevity is because software bloats. A responsible thing would be optimizing software for power and resource usage.
- Jochim 3y agoSoftware bloat isn't the entire argument at all. Hardware also fails. If it fails in your macbook, or any brand where it's soldered on, you're left with an expensive brick. I believe that being able to easily and cheaply replace those components matters.
- wongarsu 3y agoApple offering 8GB RAM in a $1,600 laptop is especially egregious, but small RAM sizes are an endemic across most laptop brands. In a desktop getting 128GB is no problem, beyond that you reach the realm of "workstations" with a significant price hike. Yet even high-end laptops frequently only offer a range from 8GB to 32GB, with the occasional 64GB for a specific model at high markup. I get the trend to soldered-on memory. I don't like it from a longevity standpoint, but it does provide space and performance benefits. But why are all laptops so low on memory?
- jamedjo 3y agoBattery life is significant worse with 32GB ram and laptop reviews often place heavy emphasis on battery life. By offering an 8Gb base model for reviews the manufacturer ensures their laptop will score well in reviews, even if users end up buying a higher spec laptop. It also allows users who want to multitask less to get more out of their laptop. On desktop the impact of power consumption is lower, so it is better to offer a slightly higher spec base model.
- kees99 3y ago> with the occasional 64GB for a specific model at high markup. That's very much the point of soldered-down RAM, isn't it? 64GB kit (2x32GB) of 260-pin (SO-DIMM) DDR4 modules show up around $110 on amazon. But why would manufacturer give customers such option, if they can be forced to buy whole new laptop instead?
- duped 3y agoIt has a lot more to do with physical space of the SODIMM slots, and in Apple's case the raw performance of on-die memory.
- throwaway49594 3y agoIf you have talented engineers this is a solvable problem. https://www.anandtech.com/show/21069/modular-lpddr-becomes-a-reality-samsung-introduces-lpcamm-memory-modules https://www.anandtech.com/show/21069/modular-lpddr-becomes-a...
- cosmotic 3y agoThe presented evidence isn't very convincing. If the author had less memory, the browser would be (or already is) swapping individual tabs to disk and many of his apps wouldn't be caching things in memory as aggressively while in the background. The real key here is the PCIe NVMe bandwidth. If macos could swap in and out all of two entire memory heavy applications in a fraction of a second, the RAM size isn't as important as it used to be.
- soniman 3y agoWhat is a good level of PCIe NVMe bandwidth?
- throwaway49594 3y agoIf NVMe bandwidth was increased it would be less noticeable and lead to more SSD thrashing. There's a decent chance the soldered on SSD's would die before the end of the warranty period and they can't have that.
- tedunangst 3y agoI'm very happy with an 8GB laptop (several actually) doing more than basic tasks, but the secret may be not doing basic tasks like running a music player that requires 1 GB of ram all to itself. Leaves more memory for the compiler. Author mentioned this in passing, but I think could have reflected more on how it is so much ram is used to do so little, lest they find their 64 GB machine obsolete as well. (I think $1800 is an absurd price for an 8GB laptop.)
- cozzyd 3y agoPeople use text editors that seem to use multiple GB of ram (based on oomkiller reports on a shared server I manage) these days, it's absolutely insane.
- orwin 3y agoAt startup I'm pretty sure any decently sized project with enough dependencies opened with projectile (or any project management tool) will eat up your ram, at least to build its index. Not sure how to avoid it.
- pshc 3y agoI use Safari on my Macbook Air 16GB. Fast, saves RAM, energy efficient, just works.
- guidoism 3y agoThe author has Chrome and Electron apps. Not sure this is normal usage. Grandma doesn’t use anything but what comes with the Mac. It’s fascinating how we all try to extrapolate assuming our usage is the norm. I do the same. But we all have different expectations.
- cozzyd 3y agoYeah but if the non-removable storage doesn't reach its rated lifetime in a year or two from constant swapping, then not as many people would need to buy new laptops.
- winwang 3y agohttps://www.reddit.com/r/mac/comments/14tdemi/swap_memory_can_damage_the_ssd_in_long_run/ https://www.reddit.com/r/mac/comments/14tdemi/swap_memory_ca... Seems like it should easily last 5 years even with constant full utilization of 8GB RAM.
- dragontamer 3y agoRAM-capacity matters. Apple products have chosen to have higher-speed RAM that has lower capacity. PC users have the more standard (higher-capacity, but slower) RAM modules. I'm sure everyone remembers the crazy MiniZinc benchmarks on Apple products, as well as other incredible RAM benchmarks. Yeah, when you directly solder RAM to the motherboard, and/or directly stack the RAM on top of the CPU, you can make more assumptions about communication... and that channel can likely have lower capacitances or other physical features. Even 10-centimeters is about 2-clock ticks (assuming 4GHz clock), aka 0.5 nanoseconds, worth of distance. So that physical distance is in fact a substantial distance away when we're talking about nanosecond-scale communications that regularly take place between a CPU and RAM. --------------- But its a tradeoff. By having the assumption that RAM is further away in typical PCs, we can stuff more RAM 10-centimeters away or 20-cm away on larger server motherboards (aka: sticks-and-sticks of different RAM). But Apple makes a much smaller assumption: 0-cm... directly soldered on top of these M1 chips. Guess what? After 8GB of RAM, they've run out of room and they literally can't expand anymore unless they increase the assumed centimeters worth of distance out. BTW: Thank your EE for equalizing all the trace-lengths to all your RAM chips. Don't believe me? Take a good look at a motherboard close to the RAM and/or CPU, I guarantee you'll see the "wavy" lines of PCB-traces as the EE in charge of the PCB-design is trying to trace-length match all the different wires to the RAM.
- themadturk 3y agoI'd kinda like to know what "pro-level web browsing" is. I have an M1 Macbook Air with 8GB RAM. The choice between 8 and 16GB was strictly a monetary one. I wish I'd bought 16GB, but I don't regret buying 8GB. I mostly run native apps, close down ones I'm not using, a rarely have more than a dozen Safari windows open at once. The only Electron app I run is Obsidian. I'm using some swap, but have never had an out of memory alert in three years. I hope when it comes time to replace my Air, I'll be able to afford more memory. Until then I'm doing just fine.
- thejohnconway 3y agoMacs have always been RAM starved at the base models. It always struck me as surprisingly cheap move from what was meant to be a premium company — they would happily sell you a Mac that would perform badly with contemporary software. But you could upgrade it yourself, of course, and that’s what all the old Macheads would advise you do. These days… urg! Their SSDs are ridiculously tiny too, which I think is even more egregious. My computing habits might not require more RAM in the future, but my storage requirements always go up.
- whatindaheck 3y agoOverall I agree 8GB is a joke in a “pro” laptop that costs as much as it does. But the author is a little off base imo. 1. How macOS uses RAM changed a few years back. Memory Pressure is just important of a metric as usage because data is intelligent cached to fill memory. The author’s screenshot shows there’s no memory pressure on their machine while arguing there’s not enough memory. My RAM is usually pretty “full” but a lot of it is pre-loaded data. 2. It seems like the author uses quite a few Electron apps. Maybe I’m shifting the blame here but Electron is a known resource hog. I’ve seen Signal use more resources than a full Linux VM. Native apps are usually faster, less resource intensive, and oftentimes follow the HIG / have better UX. For the user there’s no downside. 3. There’s different “pros” out there. So often us developers think we need these big dank machines just to work inside Vim all day. I’m extremely guilty of that. And having headroom is nice. But even an entry MacBook Air could do the job. It’s not as fun but it’d be fine.