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> In fact since Apple is migrating the entire line-up, it's likely the next generation of CPUs will support discrete RAM I've been wondering about how much of

> In fact since Apple is migrating the entire line-up, it's likely the next generation of CPUs will support discrete RAM I've been wondering about how much of the general purpose performance boost of M1 is due to having the RAM in the same package. That has to have benefits in power and latency. So if a future Mx chip supports discrete RAM, it may not seem quite as magical anymore. Then again, Apple's volume and margin is high enough that they could just build a single package with lots of RAM. You wouldn't be able to tinker with it, but it's not like Apple cares about that. Makes you wonder if AMD or Intel will come up with a similar package for x86-based laptops.

theshrike79 6y ago
As far as I understand about chip design (not much), the fact that the memory is inside the same package allows Apple to do stuff that would never fly with unknown external memory. They know the exact latencies and can distribute the memory between CPU and GPU as they please. A loss in upgradeability is a huge gain in speed and reliability. My bet is that the next M processor will just have more of everything. More cores and more built-in memory. Maybe the one for the (i)Mac Pro will have upgradeable memory on top of the built-in ones. All of the laptops will only have the on-package memory.
- lucian1900 6y ago
  Perhaps it'll be possible to use external memory as a first layer of swap. For most workloads the difference would be minimal.
ogre_codes 6y ago
Apple makes it very clear in their materials that their unified memory is a very big part of their performance boost. > So if a future Mx chip supports discrete RAM, it may not seem quite as magical anymore. I agree, but I also doubt they will be making a Mac Pro SOC with huge amounts of RAM aboard either. I'm not sure how common they are, but Apple supports up to a terra-byte of RAM (maybe more). I could easily see SOCs with 64GB of RAM, but I'm struggling with them putting 128 or 256GB+ on the SoC. Maybe some kind of hybrid? Very curious to see how they are going to work around this.
- ema 6y ago
  Doing a hybrid approach which is basically swap to off-chip ram shouldn't be too hard.
  - ogre_codes 6y ago
    It would be interesting if Apple treated their off-chip RAM as a RAM disk. Could make for some intriguing possibilities. So you'd "swap" from the hot/ on chip RAM into slower GDDR RAM instead of to the SSD.

theshrike79 6y ago

As far as I understand about chip design (not much), the fact that the memory is inside the same package allows Apple to do stuff that would never fly with unknown external memory. They know the exact latencies and can distribute the memory between CPU and GPU as they please. A loss in upgradeability is a huge gain in speed and reliability. My bet is that the next M processor will just have more of everything. More cores and more built-in memory. Maybe the one for the (i)Mac Pro will have upgradeable memory on top of the built-in ones. All of the laptops will only have the on-package memory.

lucian1900 6y ago
Perhaps it'll be possible to use external memory as a first layer of swap. For most workloads the difference would be minimal.

ogre_codes 6y ago

Apple makes it very clear in their materials that their unified memory is a very big part of their performance boost. > So if a future Mx chip supports discrete RAM, it may not seem quite as magical anymore. I agree, but I also doubt they will be making a Mac Pro SOC with huge amounts of RAM aboard either. I'm not sure how common they are, but Apple supports up to a terra-byte of RAM (maybe more). I could easily see SOCs with 64GB of RAM, but I'm struggling with them putting 128 or 256GB+ on the SoC. Maybe some kind of hybrid? Very curious to see how they are going to work around this.

ema 6y ago
Doing a hybrid approach which is basically swap to off-chip ram shouldn't be too hard.
- ogre_codes 6y ago
  It would be interesting if Apple treated their off-chip RAM as a RAM disk. Could make for some intriguing possibilities. So you'd "swap" from the hot/ on chip RAM into slower GDDR RAM instead of to the SSD.