This information is collected from: Cynthia Nottingham, and her article: virtual-machines-windows-sizes
The standard sizes consist of several series: A, D, DS, F, Fs, G, and GS. Considerations for some of these sizes include:
- D-series VMs are designed to run applications that demand higher compute power and temporary disk performance. D-series VMs provide faster processors, a higher memory-to-core ratio, and a solid-state drive (SSD) for the temporary disk. For details, see the announcement on the Azure blog, New D-Series Virtual Machine Sizes.
- Dv2-series, a follow-on to the original D-series, features a more powerful CPU. The Dv2-series CPU is about 35% faster than the D-series CPU. It is based on the latest generation 2.4 GHz Intel Xeon® E5-2673 v3 (Haswell) processor, and with the Intel Turbo Boost Technology 2.0, can go up to 3.1 GHz. The Dv2-series has the same memory and disk configurations as the D-series.
- F-series is based on the 2.4 GHz Intel Xeon® E5-2673 v3 (Haswell) processor, which can achieve clock speeds as high as 3.1 GHz with the Intel Turbo Boost Technology 2.0. This is the same CPU performance as the Dv2-series of VMs. At a lower per-hour list price, the F-series is the best value in price-performance in the Azure portfolio based on the Azure Compute Unit (ACU) per core.
The F-series also introduces a new standard in VM size naming for Azure. For this series and VM sizes released in the future, the numeric value after the family name letter will match the number of CPU cores. Additional capabilities, such as optimized for premium storage, will be designated by letters following the numeric CPU core count. This naming format will be used for future VM sizes released but will not retroactively change the names of any existing VM sizes which have been released.
- G-series VMs offer the most memory and run on hosts that have Intel Xeon E5 V3 family processors.
- DS-series, DSv2-series, Fs-series and GS-series VMs can use Premium Storage, which provides high-performance, low-latency storage for I/O intensive workloads. These VMs use solid-state drives (SSDs) to host a virtual machine’s disks and also provide a local SSD disk cache. Premium Storage is available in certain regions. For details, see Premium Storage: High-performance storage for Azure virtual machine workloads.
- The A-series VMs can be deployed on a variety of hardware types and processors. The size is throttled, based upon the hardware, to offer consistent processor performance for the running instance, regardless of the hardware it is deployed on. To determine the physical hardware on which this size is deployed, query the virtual hardware from within the Virtual Machine.
- The A0 size is over-subscribed on the physical hardware. For this specific size only, other customer deployments may impact the performance of your running workload. The relative performance is outlined below as the expected baseline, subject to an approximate variability of 15 percent.
The size of the virtual machine affects the pricing. The size also affects the processing, memory, and storage capacity of the virtual machine. Storage costs are calculated separately based on used pages in the storage account. For details, see Virtual Machines Pricing Detailsand Azure Storage Pricing.
The following considerations might help you decide on a size:
- The A8-A11 sizes are also known as compute-intensive instances. The hardware that runs these sizes is designed and optimized for compute-intensive and network-intensive applications, including high-performance computing (HPC) cluster applications, modeling, and simulations. For detailed information and considerations about using these sizes, seeAbout the A8, A9, A10, and A11 compute intensive instances.
- Dv2-series, D-series, G-series, and the DS/GS counterparts are ideal for applications that demand faster CPUs, better local disk performance, or have higher memory demands. They offer a powerful combination for many enterprise-grade applications.
- The F-series VMs are an excellent choice for workloads that demand faster CPUs but do not need as much memory or local SSD per CPU core. Workloads such as analytics, gaming servers, web servers, and batch processing will benefit from the value of the F-series.
- Some of the physical hosts in Azure data centers may not support larger virtual machine sizes, such as A5 – A11. As a result, you may see the error message Failed to configure virtual machine or Failed to create virtual machine when resizing an existing virtual machine to a new size; creating a new virtual machine in a virtual network created before April 16, 2013; or adding a new virtual machine to an existing cloud service. See Error: “Failed to configure virtual machine” on the support forum for workarounds for each deployment scenario.