Hope AM5 is the last such an obsolete 2-channel memory platform. Was it 2004-2005 as we got 2-channel memory with single or first dual-core CPUs? Now we have 16 cores with... still 2-channel memory. Looking forward to 4-channel AM6 socket.
Memory bound software like OpenFOAM saturates memory bandwidth already on 6-8 cores with 2-channel memory [1]. So actually we should have got 4-channel with first 16-cores CPUs long ago.
Something is always the bottleneck. On these 2-channel modern CPU, it's usually the concurrency of software; sometimes the throughput of the CPU cores; and very occasionally memory bandwidth, that sounds like a reasonably balanced system which the right amount of resources committed to each area.
Memory bound software like OpenFOAM saturates memory bandwidth already on 6-8 cores with 2-channel memory [1]. So actually we should have got 4-channel with first 16-cores CPUs long ago.
[1] https://www.cfd-online.com/Forums/hardware/198378-openfoam-b...