Azure Virtual Machines

Documentation & Guides

Virtual Machine Sizing Guide

Choosing the right size for your Azure Virtual Machine (VM) is crucial for performance, cost-effectiveness, and meeting your application's demands. This guide helps you understand the key factors and VM series available.

Key Sizing Factors

Compute Needs

Consider the processing power required. Applications with high CPU utilization, batch processing, or complex calculations will need more vCPUs and higher clock speeds.

Memory Requirements

For applications that store large datasets in memory, such as databases or in-memory analytics, ample RAM is essential. More RAM generally leads to better performance for memory-intensive workloads.

Storage Performance

The type and performance of your disk subsystem are vital. Consider IOPS (Input/Output Operations Per Second) and throughput for your data and application needs. Azure offers various disk types like Standard HDD, Standard SSD, Premium SSD, and Ultra Disk.

Networking Bandwidth

Applications that transfer large amounts of data over the network, like web servers with high traffic or distributed applications, require adequate network bandwidth. VM sizes specify their network performance.

Azure VM Series Overview

Azure provides a wide range of VM series, each optimized for specific workloads:

General Purpose (A, B, D, E, F series)

Balanced CPU-to-memory ratio. Ideal for:

  • Web servers
  • Small to medium databases
  • Development and test environments

B-series offers burstable performance for workloads with intermittent CPU usage.

Compute Optimized (F series)

High CPU-to-memory ratio. Best for:

  • Medium-traffic web servers
  • Batch processing
  • Application servers

Memory Optimized (E, M, G series)

High memory-to-CPU ratio. Suitable for:

  • Large relational databases
  • In-memory caches
  • Big data analytics

M-series are designed for the largest SAP HANA deployments.

Storage Optimized (Lsv2, Lsv3 series)

Optimized for high disk throughput and IOPS. Ideal for:

  • Big data applications (e.g., Hadoop, Spark)
  • NoSQL databases
  • Data warehousing

GPU Optimized (N series)

Equipped with NVIDIA GPUs. Used for:

  • Machine learning and deep learning
  • Visualizations and rendering
  • Video encoding

Choosing the Right Size

Start by identifying your workload's primary needs (CPU, RAM, I/O, Network). Consult the official Azure VM sizes documentation for detailed specifications, including vCPUs, RAM, Temp Storage, Max IOPS/Throughput, and Network Bandwidth. It's often beneficial to start with a smaller size and scale up if needed, or monitor performance and adjust accordingly.