Dual-socket systems are an easy way to get more cores, memory size or memory channels for your machine without buying a more expensive CPU SKU, or upgrading the platform to the next generation (which is often still years away back when those systems were operated by their former corporate owners), or building a multi-node cluster. 4-socket and 8-socket systems also exist but uncommon on second-hand market as most motherboards and CPUs do not support this feature.
Dual-socket systems are an easy way to get more cores, memory size or memory channels for your machine without buying a more expensive CPU SKU, or upgrading the platform to the next generation (which is often still years away back when those systems were operated by their former corporate owners), or building a multi-node cluster. 4-socket and 8-socket systems also exist but uncommon on second-hand market as most motherboards and CPUs do not support this feature.