Only HEDT and server platforms offer x64_64 with 32 PCIe lanes directly from the CPU. Most of those mainboards have two mechanically x16 slots, one electrically

Only HEDT and server platforms offer x64_64 with 32 PCIe lanes directly from the CPU. Most of those mainboards have two mechanically x16 slots, one electrically x16 until the other is populated, at which point both are electrically x8.