Clusters built from commodity hardware and software are cheap and ubiquitous and so they are easy to design, program and maintain. However, even as high-speed networks reach 10Gb/s speeds and modern computer architectures reach past 1Ghz, new commodity clusters are not able to harness this power. Three of the largest impediments to using commodity hardware and protocols are memory copies, interrupt pressures associated with Ethernet-sized frames and the storage and management of TCP connections in large systems. We compare approaches to relieving the major bottlenecks of TCP/IP and discuss whether commodity protocols like TCP/IP are inherently unsuited for cluster computing.