My understanding is that the only reason dGPUs generally don’t use system RAM isn’t that they don’t have access, but that the supporting software doesn’t use it out of choice because the of the speed hit (iGPUs, of course, do generally use system RAM as VRAM.)
> My understanding is that the only reason dGPUs generally don’t use system RAM isn’t that they don’t have access, but that the supporting software doesn’t use it out of choice because the of the speed hit
It looks like one of the advantages of Apples put-everything-on-the-package strategy is that they can have a very wide bus to ram, which makes using system ram for the GPU much more palatable.
Isn't the main difference that Apple is building something like 4-16 channel memory controllers in a mobile device while you normally don't get more than 2-4 channels even on a desktop? That's a lot of transistors and (potentially) power usage but if you can get on the latest node and have a market willing to pay for giant chips it lets you get impressive amounts of bandwidth.
I don't think you need the RAM to be on the same package for that, it just makes the timings easier.
The "Apple tax" isn't really a thing for midrange specs any more, but they will absolutely charge you out the nose to max things out. The top-end macs are targeted at people who won't even notice if the laptop's price is doubled.
We notice… but grumble and pay it because we’ve justified it to ourselves. There are of course outliers with heaps of money that don’t care about the cost, but few businesses are so cavalier with cashflow as to not notice and check why someone is buying a $7k laptop or $25k desktop
They charge you out the nose even to do small upgrades. $200 for bumping the SSD from 256GB to 512GB and $200 to go to 16GB RAM. You can easily find brand name good PCIe Gen 4 2TB NVMe drives for less than $200 now.
Yes, I am not exaggerating. The Framework came to around $1.8k and the Macbook Pro came to ~ $3.9k. The only compromise with the Framework is that it is a 13" screen and the Macbook pro is a 14". But that's because Apple only offers up to 24GB ram on the 13".