One reason for that is for many applications latency is much more critical than bandwidth. For PCs that’s input-to-screen latency, for servers that’s request-to

One reason for that is for many applications latency is much more critical than bandwidth. For PCs that’s input-to-screen latency, for servers that’s request-to-response. It’s possible to make multicore processors with simpler cores, design OS and language ecosystem around it, etc. Such tradeoffs will surely improve bandwidth, but will harm latency. Another reason is most IO devices are inherently serial. Ethernet only has 4 pairs, and wifi adapters are usually connected by a single USB or PCIx lane. If a system has limited single threaded (i.e. serial, PDP11-like) performance, it gonna be hard to produce or consume these gbits/sec of data.