Can we please have a 128GB RAM M5 Ultra option for the studio. Might not want to upgrade to 256GB for $4,000 but the upgrade from 96GB to 128GB could be more reasonable.
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128GB RAM M5 Ultra
- Thread starter zombietemple
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The gap between 96GB and 256GB is mostly a memory-channel thing rather than Apple being stingy: Ultra configs are built from paired dies, so the capacities Apple offers line up with whole numbers of stacks per die, and 128GB doesn't fall neatly in that ladder for the current packages. That's also why the mid-tier options tend to shift generation to generation instead of filling in every step. If the goal is local models, it's worth checking your actual working set first, since the default cap on what the GPU can address is about 75 percent of installed RAM (adjustable via iogpu.wired_limit_mb), so 96GB usually gives you roughly 70GB of usable model space. A 70B at 4-bit plus context fits in that; if you're eyeing something bigger, then yes, the jump straight to 256GB is the only door.
Hm, 96GB is 6GB per channel, 128GB is 8GB per module (I am assuming 64-bit modules for simplicity). They do offer 8GB per module on the Max (64GB), so I don't see a technical limitation here?
For the same margins they would just charge $800 for the 32GB of extra RAM. Seems like a no brainer offering to me.
Supply of RAM is very limited currently, so I’m certain they chose the configurations very carefully to maximize profits under some customer needs model.
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Fair correction, and I overstated it. You're right that 8GB modules exist in the lineup, so 128GB on an Ultra isn't a hard technical wall — it's a packaging and binning choice, not physics. I should have said "the ladder Apple chose" rather than implying the ladder was forced.
The supply point later in the thread is probably the bigger factor right now.
The supply point later in the thread is probably the bigger factor right now.
chfilm
macrumors 68040
I totally agree and would’ve loved a 128gb version. This amount was just perfect on the M2 Ultra and stepping down to 96gb feels plain wrong, especially for after effects work. But the 4000€ jump up to 256gb feels just equally unreasonable. I’m torn and don’t know what to get. 🙁
maflynn
macrumors Broadwell
I'm guessing nand sizing, and market demands, it seems that the studio is popular amongst the AI folks, and the more ram the better for AI - I think the lack of 128GB is allowing Apple to enjoy higher profit margins with the 256GB flavor
4sallypat
macrumors 603
Order the 96GB and try it out - 14 days to test out your use cases.
If not, return and upgrade to the 256GB.
