The Ultimate Guide to Choosing the Right Azure Virtual Machine

Visak Krishnakumar
The Ultimate Guide to Choosing the Right Azure Virtual Machine.jpg


Microsoft Azure offers a diverse range of cloud computing services to fulfill different business needs. These services can be used for building, deploying, and managing applications (PaaS), using software applications over the internet (SaaS), and accessing computing resources on-demand (IaaS). Businesses can use Azure to meet their specific needs and potentially scale their operations, innovate, and digitally transform. With its global presence and focus on reliability, Azure helps businesses stay competitive in a dynamic market.

What are Azure VMs?

Within the IaaS realm of Azure lies the concept of virtual machines. Azure VMs are on-demand, scalable computing resources within the Microsoft Azure cloud platform. They function as virtualized versions of physical servers, enabling you to deploy and operate applications in a highly available and secure environment.

Benefits of Using Azure VMs

But unlike their physical counterparts, Azure VMs offer multiple benefits:

  • Scalability: Effortlessly scale your VMs up or down based on fluctuating workload demands. This ensures optimal resource utilization and eliminates the need for static resource allocation, maximizing cost efficiency.
  • Flexibility: Azure's extensive selection of VM types and sizes empowers you to choose the exact configuration that perfectly aligns with your specific application requirements. This flexibility prevents wasted resources on underpowered VMs or performance bottlenecks created by over-reliance on under-provisioned ones.
  • Cost-Effectiveness: Azure offers a pay-as-you-go pricing model for VMs, allowing you to only pay for the resources you consume. Additionally, reserved instances can be used for predictable workloads, further optimizing costs.
  • Security: Microsoft Azure boasts powerful security features designed to protect applications and data within the cloud environment. These features provide peace of mind and enable you to focus on core business objectives without undue security concerns.
  • High Availability: By leveraging Azure's high availability capabilities, VMs can be designed to minimize downtime and ensure business continuity. This is achieved through features like redundancy and failover mechanisms.
  • Disaster Recovery: Disaster recovery solutions can be implemented using Azure VMs. These solutions facilitate seamless failover in unforeseen disruptions, minimizing the impact on critical business operations.

Understanding Your Needs

Azure VMs offer a vast array of configurations, each with varying compute, memory, and storage capabilities to cater to a wide range of workloads so before diving into Azure VM families, it's crucial to gain a clear understanding of your specific workload requirements. Here are the key factors to consider:

  1. Workload Requirements (CPU, Memory, Storage)
    • CPU: Analyze the processing needs of your application. Does it require a high core count for parallel processing tasks, or will a single core suffice?
    • Memory: Determine the memory requirements of your application. Will it benefit from a large RAM capacity for in-memory processing, or is a moderate amount sufficient?
    • Storage: Evaluate the storage needs of your application. Does it necessitate high-performance storage with low latency (e.g., SSDs), or is standard HDD storage adequate?
  2. Scalability Needs
    • Vertical Scaling: Consider whether your application requires the ability to increase resources (CPU, memory) within a single VM instance.
    • Horizontal Scaling: Evaluate if the need exists to scale your application by adding or removing VM instances.

Common Challenges

Choosing the right VM type can be a complex process for technical professionals. Here are some common challenges you might encounter:

  1. Complexity of VM Families

    The sheer variety of VM families, each with distinct characteristics, can lead to confusion. Understanding the nuances of each family and their suitability for specific workloads requires in-depth knowledge.

  2. Matching Needs with Resources 

    Accurately identifying your workload requirements (CPU, memory, storage) is crucial for selecting the optimal VM size. Choosing a VM with insufficient resources can lead to performance bottlenecks, while overprovisioning incurs unnecessary costs.

  3. Staying Up To Date with Evolving Options

    Microsoft keeps adding new virtual machine families and sizes to its lineup. Another level of complexity is added by staying up to date with these updates and comprehending how your cloud infrastructure may be affected.

Azure VM Families

Having established an understanding of your workload requirements, the next step is to explore the diverse spectrum of Azure VM families. Each family is meticulously crafted to address specific use cases:

  1. General Purpose 

    This family is ideally suited for a wide range of production workloads, encompassing web servers, application servers, development environments, and small to medium-sized databases. General-purpose VMs offer a well-balanced combination of CPU, memory, and temporary storage, making them versatile for diverse application needs.

    • Av2-series: These cost-effective options are well-suited for less demanding workloads with minimal CPU and memory requirements.

      Ideal for:

      • Development and test environments: Av2 series VMs provide a cost-efficient platform for building, testing, and deploying applications without breaking the bank.
      • Low-traffic web servers: These VMs are suitable for hosting websites with moderate user traffic, ensuring a smooth user experience without incurring excessive costs.
      • Basic file and print servers: Av2 series offers a cost-effective solution for hosting basic file and print services within your organization.

      Key Considerations: Av2 series VMs prioritize cost-efficiency over raw performance. If your workloads require significant processing power or extensive memory, consider exploring other series within general-purpose VMs.

    • B series:  Designed for workloads requiring a balance between CPU and memory resources, making them suitable for development environments and low-traffic web servers.

      Ideal for:

      • Development environments: B-series VMs provide a good balance of resources for development teams to build, test, and debug applications efficiently.
      • Low-traffic web servers: These VMs can effectively handle websites with moderate user activity, ensuring smooth performance for your audience.
      • Small to medium databases: B-series offers sufficient resources to host smaller databases that don't require the highest processing power or extensive memory.

      Key Considerations: While B-series offers a balance, workloads with intensive CPU or memory requirements may benefit from exploring D-series VMs within General Purpose.

    • Dav4/Dasv4 series: Offer superior performance with hyper-threading technology, making them ideal for CPU-intensive workloads such as batch processing and scientific simulations.

      Ideal for:

      • Batch processing: Dsv4/Dav4 series VMs excel at processing large datasets efficiently, making them ideal for batch processing tasks like data analysis and scientific simulations.
      • Web servers with moderate to high traffic: These VMs can effectively handle websites with significant user activity, ensuring smooth performance even during peak traffic.
      • Virtual desktops: The Dsv4/Dav4 series offers sufficient resources to host virtual desktops with a good user experience for applications that don't require exceptional graphics processing capabilities.

      Key Considerations: Dsv4/Dav4 series offers a significant performance boost compared to Av2 and B-series VMs. However, this performance comes at a slightly higher cost. Evaluate your workload's needs to determine if the performance gains justify the increased expense.

      Azure VM Types (General Purpose).svg

  2. Compute Optimized

    This family caters to computationally intensive workloads such as scientific computing, high-performance computing (HPC), and video editing. Fsv2/Fsr VMs provide high core counts and faster CPUs to tackle demanding calculations efficiently.

    • Fsv2 series: Ideal for CPU-bound workloads with minimal memory requirements, excelling in tasks like scientific modeling and simulations.

      Ideal for:

      • Scientific Modeling and Simulations: Performing complex calculations in physics, engineering, and materials science that benefit from high core counts and fast CPUs.
      • Financial Modeling and Risk Analysis: Running simulations and calculations for financial forecasting, risk assessment, and portfolio optimization, leveraging the processing power of Fsv2 VMs.
      • High-Throughput Batch Processing: Processing large datasets efficiently in scenarios where memory requirements are secondary to raw CPU power.
    • Fsr series: Offer a balance between CPU and memory, catering to mixed workloads with high compute needs such as video editing and engineering simulations.

      Ideal for:

      • Video Editing and Rendering: Processing high-resolution video projects, applying effects, and rendering final outputs efficiently.
      • Engineering Simulations: Running simulations for product design, mechanical engineering, and other applications that require both processing power and data storage.
      • Data Analysis with Moderate Datasets: Analyzing datasets of moderate size while leveraging the processing power for complex calculations.

        Azure VM Types (Compute Optimized).svg

  3. Memory Optimized

    This family is geared towards workloads that heavily rely on in-memory processing, demanding large RAM capacities for rapid data access.

    • E series:They cater to applications that heavily rely on in-memory processing. These workloads demand significant RAM capacities to ensure rapid data access and manipulation.

      Ideal for: Workloads that benefit from significant RAM but don't require the absolute highest memory configurations. Examples include:

      • Large Relational Databases: E-series VMs are well-suited for hosting large relational databases like SQL Server and Oracle. The ample RAM allows efficient storage and retrieval of frequently accessed data, leading to faster query processing and improved application performance.
      • In-Memory Analytics Platforms: Platforms like Apache Spark leverage in-memory processing for real-time analytics. E-series VMs provide the necessary RAM capacity to store and analyze large datasets in memory, enabling faster insights and quicker decision-making.
      • Big Data Processing Tools: Tools like Hadoop benefit from the substantial memory offered by E-series VMs. This allows them to process massive datasets efficiently and complete tasks like data aggregation and analysis promptly.

      Key Considerations:

      • Cost-Effectiveness: E-series VMs strike a balance between high memory capacity and cost-efficiency. While they offer significant RAM, they may not be the most expensive option compared to other memory-optimized series. This makes them a good choice for workloads that require substantial memory but don't have an absolute need for the highest configurations.
      • Security Options: While hardware-based memory encryption might not be universally available across all E-series instances, some configurations support Secure Encrypted Virtualization - Secure Nested Paging (SEV-SNP) for enhanced security. Evaluating your specific security requirements is crucial when choosing an E-series VM type.
    • M series: Delivers the highest memory configurations within Azure VMs, ideal for workloads requiring exceptional in-memory processing capabilities.

      Ideal for: Applications that demand the absolute most RAM for intensive processing, such as:

      • In-memory databases: Applications like SAP HANA, which rely on in-memory databases for real-time data processing and analytics, benefit tremendously from the sheer memory capacity offered by M-Series VMs.
      • Real-time fraud detection systems: These systems require rapid analysis of large volumes of data to identify fraudulent transactions in real time. M-Series VMs can handle these demanding workloads efficiently, minimizing the risk of fraudulent activities.
      • High-performance analytics engines: Complex data analytics tasks often involve processing massive datasets. M-Series VMs empower these engines to perform analytics at exceptional speeds, enabling faster decision-making based on data insights.

        Azure VM Types (Memory Optimized).svg

  4. Storage Optimized

    This family is optimized for workloads demanding high disk throughput and I/O performance, critical for rapid data access and processing.

    • Lsv2 series: Hyper-threaded VMs with high core counts and local NVMe storage, Lsv2 VMs deliver exceptional performance for demanding storage workloads.

      Ideal for:

      • High-performance computing (HPC) workloads that involve massive data analysis and scientific simulations.
      • Real-time data processing pipelines that require rapid data ingestion and manipulation.
      • Video editing and rendering applications that benefit from fast storage access for large media files.
    • Lasv3 series: These VMs provide local SSDs with a balanced configuration of vCPUs and memory, catering to storage-intensive applications that also require moderate compute resources.

      Ideal for:

      • Database servers manage large datasets, where frequent data access and updates are crucial.
      • Data warehousing applications that store and analyze historical data for business intelligence purposes.
      • Content delivery networks (CDNs) that require fast storage access for efficient content delivery.

        Azure VM Types (Storage Optimized).svg

  5. GPU 

    This family is designed for workloads that leverage the power of graphics processing units (GPUs) for tasks requiring high levels of parallelism and acceleration.

    Ideal for:

    •  Machine Learning and Deep Learning: Training complex machine learning models and performing deep learning inferences benefit significantly from the parallel processing capabilities of GPUs. N series VMs can significantly accelerate training times and enable the development of more sophisticated models.
    • Video Editing and Processing: N series VMs streamline video editing workflows, enabling faster rendering, encoding, and decoding of high-resolution video formats. This translates to smoother editing experiences and faster project completion times.
    • Scientific Simulations: N series VMs accelerate complex scientific simulations commonly used in computational physics, fluid dynamics, and weather forecasting. The parallel processing power of GPUs allows for faster simulations and the exploration of more intricate models.
    • Financial Modeling and Risk Analysis: N series VMs can expedite financial simulations and risk analysis tasks, enabling faster portfolio optimization and more efficient risk management strategies.

    The choice of GPU type and quantity within the N series will depend on the specific requirements of your workload.

    Azure VM Types (GPU).svg

  6. High Performance compute (HPC)

    This family caters to scenarios requiring exceptionally high computing power, massive memory capacity, and ultra-fast storage. HPC VMs are ideal for large-scale scientific modeling, simulations, and weather forecasting. 

    Ideal for:

    • Large-scale scientific modeling and simulations: HPC VMs are instrumental in simulating complex physical or biological phenomena, accelerating research and development in various fields.
    • Weather forecasting: These VMs enable intricate weather simulations for accurate predictions, crucial for preparedness and risk mitigation.
    • Financial modeling and risk analysis: HPC VMs facilitate complex financial models and simulations to assess risk and optimize investment strategies.
    • Seismic data processing: The high computing power and fast storage of HPC VMs are ideal for processing and analyzing vast quantities of seismic data, essential for oil and gas exploration and geophysics.
    • Drug discovery and materials science: HPC VMs accelerate simulations and calculations involved in drug discovery and material science research, leading to faster breakthroughs.

      Azure VM Types (High Performance Compute).svg

By aligning your workload needs with the strengths of each VM family, you can establish a solid foundation for selecting the optimal VM type for your specific requirements.

VM Type

Key Considerations

Use Cases

Ideal For

General PurposeCost-effective, balanced CPU, memory, temporary storageVersatile workloadsWeb servers, application servers, development environments, small to medium databases
Compute OptimizedHigh core counts, faster CPUsComputationally intensive workloadsScientific computing, HPC, video editing, simulations
Memory OptimizedLarge RAM capacitiesIn-memory processing workloadsDatabases, caching layers, in-memory analytics
Storage OptimizedLocal SSDs, high I/O performanceHigh disk throughput workloadsLarge databases, data warehousing, Big Data analytics, real-time applications
GPUDiverse GPU types and configurationsWorkloads requiring GPU accelerationMachine learning, deep learning, video editing, scientific simulations
High-Performance Compute Exceptionally high compute power, massive memory, ultra-fast storageLarge-scale scientific computingScientific modeling, simulations, weather forecasting

Advanced Considerations

While VM family and size selection form the core of your decision, here are some additional factors to consider for optimal performance and resource utilization:

  1. Temporary vs. Managed Disks

    Temporary disks are short-lived, meaning they disappear when the VM is stopped or de-allocated. Utilize them for transient data that doesn't require persistence. Managed disks, on the other hand, are persistent and remain available even after VM termination. Use them for critical data that needs to be preserved.

  2. Network Optimization with Accelerated Networking

    For latency-sensitive applications requiring high-performance network communication, leverage Azure's Accelerated Networking feature. This utilizes specialized hardware to enhance network throughput and reduce latency for your VMs.

  3. Monitoring and Performance Optimization

    Once your VM is deployed, actively monitor its performance metrics (CPU, memory, storage utilization) to identify potential obstacles or resource imbalances. Azure provides comprehensive monitoring tools and services to help you optimize performance and potentially adjust your VM size or configuration if needed.


By carefully considering the factors outlined in this guide, you can make informed decisions when selecting the optimal Azure VM type and size for your workload requirements using CloudOptimo’s CostCalculator. Remember, the ideal VM choice represents a delicate balance between performance needs, cost-effectiveness, and scalability.

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