PCI Express (PCI-E) comes in various configurations, and it's easy to get tripped up by the terminology. So here are a few practical examples of the bandwidth of some current and future PCI-E interface cards:
A Gigabit Ethernet card uses about 100 MB per second, for instance, and a 2-Gb Fibre Channel card uses roughly 200 MB per second. Theoretically, a 4-Mb Fibre Channel card uses 400 MB per second. 10-Gb Ethernet and the upcoming 10-Gb Fibre Channel specifications will use up to 1,000 MB, or 1 GB per second, in transfer rates. A 16x PCI-E configuration, meanwhile, performs at a theoretical 4 GB per second.
There, numbers can be confusing. For instance, a 16x configuration is a 4-GB connection because the interface can perform 4 GB in each direction. But some companies and the PCI-SIG call this an 8-GB-per-second connection, with 4-GB per second in each direction. (Why? Marketing.) It's important to consider this when reading card and server vendor specifications: Some use the PCI-SIG's "total bandwidth" definition, and others the symmetrical bandwidth number.
Discover the benefits of scalable backbone and network services for application and cloud providers.
Network automation is gaining momentum. Here's how you can drive this powerful technology to its full potential.
Subsea cable alternatives can provide a level of comfort for those concerned about disruptions. Realistically, they will continue to play a small, but critical role in the short term.
