If computer clocks max out somewhere around 5GHz, how is it possible for 100Gbit internet to exist? How does the computer possibly transfer that much data per second?

Question

If computer clocks max out somewhere around 5GHz, how is it possible for 100Gbit internet to exist? How does the computer possibly transfer that much data per second?

In: 591

Answer 1

The CPU’s frequency is not relative to the CPU’s transfer of data. The transferring of data is done by a CPU controller over PCIe. PCIe 3.0 has a max theoretical bandwidth of 8 Gigatransfers per second which equates to about 512 Gbits per second, *however*, PCIe channels are typically split into 20 channels(lanes) depending on the CPU. Intel Core processors usually have 20, Xeons can have anywhere from 24 to 80 lanes. One of the main PCIe channels is your GPU which takes up 16 of it’s own and leaves 4 channels for other devices such as a network adapter. *Theoretically*, 2 PCIe lanes can achieve 128 GBits per second transfer speeds. Of course that’s impossible because of the interface overhead like 128b/130b encoding. Manufacturers can claim 100GBit transfers based on the fact that their adapters are using 2 PCIe lanes.

These days PCie 4.0 and 5.0 are available essentially doubling the bandwidth from generation to generation respectively. 16GT/s to 32GT/s.