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What's with the 36 GB option? The other memory configs (16 GB, 64 GB) are still clean powers of two. Size suggests that they're using ECC-capable memory but usi
by addaon 3y ago
What's with the 36 GB option? The other memory configs (16 GB, 64 GB) are still clean powers of two. Size suggests that they're using ECC-capable memory but using the extra width intended to support ECC for data... but why would this only apply to a single size? Part availability?
EDIT: Digging this a bit, it's not (one or more) 72-bit wide busses with 2^32 words as I'd expect as a gray-beard, it's (probably) six 32-bit wide busses with 6 GiB per bus; and this use of 1.5 * 2^N deep memories has become relatively common with the use of IC stacking, with 12 power-of-two sized ICs stacked in a single package (instead of the more "comfortable" 8 high or 16 high stacks of the same ICs giving powers of two).
- fastball 3y agoI prefer that tbh. If I'm frequently saturating 16GB of memory in the previous gen and it is time for an upgrade, I probably don't need literally double the memory, but 24GB would be nice.
- LeoPanthera 3y ago64 GB chips that failed testing? That's one way to increase yield. Clive Sinclair did that trick back in the 80s.
- willk 3y agoIntel and AMD do that now with processors.
- minimaxir 3y agoApple did binning back with the original M1. (either 7-core or 8-core models)
- sys_64738 3y agoUncle Clive.
- addaon 3y agoDoesn't look like it. Memory ICs are tested before packaging, and then are packaged in stacks. While I'm sure there's some loss in packaging, probably not enough to justify this level of binning; and most of the failures that would happen at this stage would potentially interfere with signal integrity for the whole stack. Instead, it looks like after the 8-high stacks that I knew about, manufacturers went to 12-high stacks. There are 16-high stacks available too, but looks like there's a lot more backside thinning needed to keep the same Z height so cost goes up disproportionately and 12-highs are a reasonably sweet spot for capacity per dollar.
- wtallis 3y agoThere are non power of two sized DRAM dies in production these days; it's not purely a matter of stacking (and stacking doesn't make it any easier to have something in between one die per channel and two dies per channel). You can get 24GB single-rank and 48GB dual-rank DDR5 UDIMMs compared to a year ago when the options were 16GB and 32GB; no stacking at all, just going from 16Gbit to 24Gbit per die. But LPDDR has been doing this for longer due to demand in the smartphone market.
- stetrain 3y agoThey've been doing more multiples of 6/12 lately, I supposed it's related to the available chip sizes for the LPDDR5X. M2 and M3 go up to 24GB M3 Pro is available in 18GB and 36GB M3 Max is available in 36GB, 48GB, 64GB, 96GB, and 128GB
- rickette 3y agoWhy do I need to select the most expensive M3 Max version (the one with 16 cores) to get 48 or 64 gigs of RAM. The M3 Max with 14 cores only allow 36 or 96 gigs. Just let me choose 14 cores and 64 gigs.
- stetrain 3y agoIn previous gens they had different die sizes with different physical numbers of memory controllers and connections. Guessing it's similar here. Rumor is Apple bought all of TSMC's initial 3nm production. They are probably yield limited on full featured chips.
- spookie 3y agoMost likely. Let's not kid ourselves, there would be more players sharing those if they felt it was worth it.
- coffeebeqn 3y agoYou are in their target market of who they can really squeeze since you want something a little bit special. Their memory pricing has always been absurd. Even on an older MacBook it was often +$200 for something silly like a 16GB SODIMM that costs $50 at the store. I still think their build quality , screen quality and OS are pretty much unmatched.
- tqkxzugoaupvwqr 3y agoIt’s worse. The configurator is labeled with a relative price upgrade but an absolute RAM size. The actual deal is +$200 for +8 GB RAM which is outrageous.
- easton 3y agoThere’s also a 18GB M3 Pro config of the MacBook Pro. Very unusual.
- isametry 3y agoOne and a half 12-chip? Or a 12 plus a binned 8?
- kccoder 3y agoIt also appears they've dropped the memory bandwidth from 200GB/s on the M1/M2 Pro to 150MB/s on the M3 Pro, and you have to upgrade to the tippy top M3 Max chip to get the full 400MB/s bandwidth experienced on the M1/M2 Max chips.
- gtirloni 3y agoI remember getting one of those shiny aluminum MacBooks in 2009. Then MacBooks turned plastic and the aluminum ones became MacBook Pro's. Is this a thing Apple does? I'm not an Apple customer for many years now.
- nomel 3y agoApple hasn’t had any plastic devices for some time now.
- gtirloni 3y agoI'm referring to the 2010 polycarbonate one here: https://everymac.com/systems/apple/macbook/specs/macbook-core-2-duo-2.4-white-13-polycarbonate-unibody-mid-2010-specs.html https://everymac.com/systems/apple/macbook/specs/macbook-cor... Not sure why my initial comment is -4 votes right now. What am I remembering wrong?
- dmix 3y agoNothing it’s a perfectly fine question, just maybe off topic.
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- wtallis 3y agoWhat you described as a transition to plastic for the MacBook was actually the final iteration of a fairly long line of plastic MacBooks, most of which were a pretty similar design to the pre-Intel iBook. "MacBook" (not Pro) was plastic from the start, and introduced the same year as the MacBook Pro (always aluminum): 2006. The plastic MacBook was discontinued after the 2010 model. There was a one-off aluminum 13" MacBook in 2008, but it coexisted with the plastic MacBook and was not replaced by a plastic model—instead, the 13" model was promoted up to the MacBook Pro product line, which previously had been just 15" and 17". After several years of not having a plain MacBook, Apple did the 12" aluminum MacBook from 2015 to 2017. It was basically what they wished the MacBook Air could be, but was too expensive and too thermally constrained to truly replace the MacBook Air of the time. It was killed when they finally upgraded the MacBook Air to have a Retina display.
- ksec 3y agoIt has nothing to do with ECC. They are using LPDDR5X memory, and if you follow Android phones these number shouldn't be surprising.