How Can I Achieve 40GBPS on My New PC Build?

You should reconsider the necessity of 40GBPS. Bandwidth and latency are different—more bandwidth doesn’t equal less latency. For most users, 10GBPS is more than enough. If you're just connecting to the internet, consider using a good Ethernet connection; your ISP speeds might not even come close to 40GBPS. Most motherboards have a 10GBPS Ethernet port, and you might need a special PCIe card if you want more.

To get 40GBPS, you first need to clarify what you're referring to: is it network transfer rates or disk I/O? For networking, you can use a QSFP+ adapter connected to a QSFP+ switch, but you also need fast disks to utilize that speed. If you're looking at Ethernet, you could bond several 10GB Ethernet ports together. Just so you know, standard WiFi won't get you anywhere near that speed.

You can't realistically achieve 40GBPS over WiFi yet—that's more theoretical. To hit those speeds over Ethernet, you'll need specific hardware: a 40GbE NIC like the Mellanox ConnectX-4, a compatible switch (like Cisco Nexus), and appropriate cables like QSFP+ DACs or fiber optics. Plus, you'll want super-fast SSDs to take full advantage of the potential speeds.

It sounds like you might be confusing USB 4 ports with WiFi 7 features. Many WiFi 7 motherboards do support USB 4, but you don't need a WiFi 7 board for that speed. If you don’t need USB 4 or a WiFi 7 router, those features may not be necessary for building your PC.