How much higher bandwidth, percentage wise, can one expect from integrated DRAM vs socketed DRAM? 10%?
Intel's Lunar Lake low-power laptop processors launched in fall 2024 use on-package LPDDR5x running at 8533MT/s, as do Apple's M4 Pro and M4 Max.
So at the moment, soldered DRAM offers 33% more bandwidth for the same bus width, and is the only way to get more than a 128-bit bus width in anything smaller than a desktop workstation.
Smartphones are already moving beyond 9600MT/s for their RAM, in part because they typically only use a 64-bit bus with. GPUs are at 30000MT/s with GDDR7 memory.