More channels allow more memory bandwidth, though actual performance gain is marginal unless the data being processed has very strict spatial locality (e.g. flu

More channels allow more memory bandwidth, though actual performance gain is marginal unless the data being processed has very strict spatial locality (e.g. fluid dynamics simulations), most other workloads are more constrained by cache. The real reason for adding more memory channels to a general purpose CPU is actually to increase the maximum amount of memory per node. A few years ago, workstation and server platforms often allowed 3 or more DIMMs per channel with performance declining sharply with memory density. Since then both AMD and Intel have limited each channel to 2 DIMMs and increase the number of memory channels from 4 to 6/8 to make up for the loss. While more memory channels do enable better performance scaling, it has also made the CPU socket more complex and fragile than ever: The TRX40 socket has 4094 pins and literally requires the CPU to be bolted down using a torque wrench to ensure good contact.