Azure VM Bandwidth and IOPS

When it comes to fine-tuning Network and Storage performance of Virtual Machines here are some things to consider

Networking (Bandwidth)

1. Accelerated Networking reduces network latency, improves throughput and decrease CPU utilization of a Virtual Machines. If you need above deploy select supported Virtual Machine SKUs always enable this feature.  
2. The bandwidth limit is cumulative of all outbound traffic from the virtual machine (see here). So for example, if you use Standard_D1_v2 Virtual Machine SKU you can have a max of 700 Mbps and for Standard_D2_v2 its 1500 Mbps

Storage ( IOPS / Throughput)

• Every Azure Managed Disk size has Max IOPS and Max Throughput (see here)
• Every VM has a limit on how much throughput and IOPS it can provide (see example)
• So the overall throughput / IOPS you can get is capped by min of (VM, Managed Disk)

Also, Consider

• You can optimise disk Read IOPS by enabling caching, improve performance by implementing Striped Volume etc. (see here)
• Ultra-disks allows you to choose desired IOPS/Throughput  (max IOPS: 160,000 and Max Throughput: 2,000)
• If you wish to benchmark your disk performance consider IOMeter tests

Finally

• If you are using Azure Files or NetApp files remember they use Network Bandwidth vs IOPS so choose a SKU that optimises Network performance.