Why not both? A little DRAM on SoC and the rest of the DRAM on the motherboard. Kernel in charge of "swapping". Maintains expandability while keeping most of the performance benefit.
How? You're basically describing RAM caching. Putting all the ram physically close to the processor gives a giant performance gain that's mostly lost if any of the system's RAM is "remote" on the motherboard.
Is there any concrete numbers to back the claim that "Putting all the ram physically close to the processor gives a giant performance gain"? Will be interesting to see what is the memory latency of M1 compared with a regular Intel/AMD processor.
It doesn't. As has been corrected time and time again.
The M1 has pretty high memory latency at around 100 ns [1], which is significantly higher than either AMD or Intel for typical systems. Note that physical distance between CPU and memory is rather less important for latency, as DRAM is high latency in itself, so adding a few ns at most due to wiring is not going to matter.
Just for context, the M1's latency is fairly close to other LPDDR4(x) systems (Tigerlake and Zen3 SoCs).
This is fairly typical of LPDDR4 compared to normal DDR4, part of the compromise.
Not the most scientific, but userbenchmark is useful because it has latency graphs available for millions of systems.
Yes. Thank You. If M1 discussion continues to be like this we have a possibly of stamping out M1 misinformation on HN.
But sometimes we are just lazy to provide the context or to spell out everything. These information is so readily available with a simple Google. And yet the past dozens of M1 thread this "memory" advantage thing keeps popping up.
