are you talking about production storage where the VMs are running, or the backup target created using the units you described?
If the first case, a faster source storage can help on reducing the backup window, if the target is not already the bottleneck, otherwise adding more power to source will not change the result. What are the bottlenecks of your job stats?
EMEA Cloud Architect @ Veeam Software
Veeam VMCE #1