With that kind of speed, I can only assume you're talking about offline attacks (e.g. John the Ripper). Also, the metrics for speed are heavily dependent on the type of password you're attempting to crack.
They key to getting speed is to 1) use software capable of maxing out hardware, and 2) throwing hardware resources at the problem.
For #1, it depends on the type of password. For example, Hashcat is great for computing hashes using GPUs. I'd also recommend John the Ripper. You'll need to be sure that you're compiling it to work with your hardware. Here are a couple of resources to dive deeper into doing so, for JTR:
For #2, here's a link to someone's cracking rig:
Note the use of multiple GPUs with heavy cooling. Also, note his results using both JTR and Hashcat.