Amazon Elastic Compute Cloud (EC2) provides scalable, pay-as-you-go compute capacity in the cloud. The engine that powers EC2 and enables flexible cloud computing is the "instance."
As AWS principal technologist Glenn Gore explains:
"An EC2 instance is basically a virtual machine running inside AWS’s vast infrastructure. You can configure and launch instances on demand to deploy just about any type of workload application."
But with over 600 different instance types available, how do you know which one is right for your needs?
In this comprehensive guide, we’ll cover everything you need to know about the 5 major categories of EC2 instances. From ideal use cases to hardware specs, monitoring tools and more – let’s dive in.
An Overview of AWS EC2
In simple terms, EC2 instances are configurable compute servers designed for virtually any cloud workload. They provide access to AWS‘s global infrastructure of servers and data centers.
Some key uses of EC2 instances include:
- Building and deploying cloud-native applications
- Running data analytics platforms and databases
- Training and deploying machine learning models
- Hosting websites, gaming servers and more
The technology that enables EC2’s high scalability and performance is the instance itself – a customizable virtual machine profile running inside AWS‘s infrastructure.
By 2023, 94% of all workload deployments are predicted to run on public, private and edge cloud infrastructure, according to IDC. EC2 continues to dominate as a go-to solution for scalable, cost-efficient cloud computing power.
Within EC2, there are 5 major instance types (or families) that you can choose from:
Now let‘s explore the differences, use cases and technical specs around each instance type in more detail.
General Purpose Instances
As the name suggests, General Purpose instances provide an equal balance of compute, memory and networking resources. This makes them suitable for a wide variety of workloads, from web servers to gaming servers, databases and more.
Some examples of ideal use cases for General Purpose Instances are:
- Running small/medium databases
- Hosting web servers, ecommerce sites and applications
- Operating development and test environments
- Hosting loosely-coupled gaming servers like matchmaking
Many General Purpose instance families fall under the AWS free usage tier, making them a popular starting point for getting to know AWS.
Some of the most widely-used General Purpose instance types are M5, M5a and T3 instances. For example:
- M5 instances use a balance of 3.1-3.6Ghz Intel Xeon Scalable processors (Skylake or Cascade Lake) with a sustained all core turbo CPU clock speed of up to 3.5Ghz.
- M5a instances run on 2.5Ghz AMD EPYC 7000 series processors, offering slightly less computing power but at lower cost.
- T3 instances are the newest generation of burstable, general purpose instances that provide a baseline level of CPU performance with the ability to burst CPU usage at any time for as long as required.
So in summary – If you need an affordable, balanced cloud server suitable for a range of workloads – General Purpose EC2 instances are the best place to start.
Compute Optimized Instances
If raw CPU power is what your workload craves above all else – Compute Optimized instances are made for you.
Applications like high-traffic web servers, on-demand batch processing, gaming servers, scientific modeling & machine learning all benefit from the maximize compute resources these instances provide.
Some examples of workloads suited for Compute Optimized instances:
- High performance web/application servers
- Real-time big data analytics or batch processing
- High performance computing (HPC) clusters
- Video encoding platforms
- Gaming servers running complex physics simulations
Compute Optimized instances feature high clock speeds, extra vCPUs and the latest processor architectures (Graviton3, Intel Ice Lake etc) to deliver blistering fast performance.
Popular options include:
- C5 instances – Up to 3.6 GHz Intel Xeon Platinum 8000 series processors
- C6i instances – Up to 3.6Ghz Intel Xeon scalable processors + up to 100Gbps in networking bandwidth
- C7g Instances – Powered by next-gen AWS Graviton3 processors delivering up to 25% better price performance vs comparable current generation x86-based instances
In short – your application requires maximum compute capacity above all else? Compute Optimized instances are purpose-built to meet those demands.
Memory Optimized Instances
For workloads that need to perform lots of read/write operations in memory – Memory Optimized instances allow you to maximize memory capacity to achieve blazing fast performance.
Applications that involve ingesting and querying vast datasets in memory prior to persistence benefit greatly from high memory instance types.
Some examples include:
- High performance databases like Redis, relational databases or in-memory caches
- Real-time big data processing platforms like Elasticsearch, SolrCloud clusters
- Data mining tools and distributed web scale in-memory caches
The most memory optimized EC2 instance type is the X1E family, offering:
- Up to 4 TB of DDR4 RAM
- Up to 3.4Ghz quad core Intel Xeon E7 8880 v3 processors
Additional Memory Optimized options like R5 offer up to 768GiB RAM with very high EBS bandwidth (up to 10Gbps) to enable speedy data transfers.
So in summary – does your workload demand giant memory capacity and blood fast read/writes? Memory Optimized instances maximize just that.
Storage Optimized Instances
For workloads requiring high, consistent IOPS performance for low latency data access – Storage Optimized instances deliver powerful local NVMe SSD disks and high sequential read/write access.
This makes them ideal for large scale databases, data warehousing and certain big data applications.
Some examples of ideal use cases include:
- NoSQL & relational databases demanding high disk I/O
- Distributed file systems used to process big data
- Data warehousing applications involving business intelligence, analytics
- Dedicated network file and data systems
I3 Instances are a popular Storage Optimized option, providing:
- Up to 64 TB NVMe SSD storage (8 x 8TB)
- Up to 100 Gbps network bandwidth
- Over 3 million 4KB IOPS (via io2 block express volumes)
The key advantage of Storage Optimized instances lies in improved application latency and high read speeds from multiple attached solid state drives.
So in summary – does your project demand high performance local storage and disk I/O above all else? Storage Optimized instances are purpose built for these kinds of data-intensive applications.
Accelerated Computing Instances
Rather than just maximize regular compute/memory/storage, Accelerated Computing instances utilize hardware accelerators like GPUs, FPGAs and Machine Learning Accelerators to deliver up to 10x better floating point performance than CPU-based options.
This makes them perfect for applications with heavy mathematical processing requirements – from scientific simulations to machine learning inferencing.
Some examples of ideal use cases include:
- Machine Learning model training/inferencing
- Speech/text recognition platforms
- Genomics & computational biology
- Financial risk modeling Monte Carlo simulations
- Game streaming platforms
- Graphics intensive applications like CAD/CAM
Popular Accelerated Computing instance options include:
- P3 Instances – Up to 8 NVIDIA Tesla V100 GPUs
- G4ad instances – AMD EPYC CPU + up to 4 AMD Radeon Pro V520 GPUs
- INF1 instances – Machine learning inference accelerators from AWS Inferentia chips delivering high throughput at low cost
The specialized hardware accelerators supercharge mathematical performance – allowing you to develop and deploy next generation AI, ML and analytics applications.
How To Choose the Right Instance Type
We‘ve covered the key differences, technical specs and ideal use cases around the 5 major EC2 instance categories.
So how do you ultimately decide what’s right for your specific workload?
Here is a helpful decision checklist when evaluating EC2 instance types:
1. Understand Technical Requirements
- What are the CPU, memory, storage, network needs?
- Will the app use GPUs or hardware accelerators?
- What are the I/O patterns and types of data processing?
2. Identify Most Important Performance Factor
- Is it pure compute speed? Memory capacity? Storage throughput? Network bandwidth? Specialized hardware?
3. Research Instance Families
- Consult AWS instance comparison tables
- Read product pages for technical specs
- Check out trusted analyst comparisons
4. Utilize AWS Pricing Tools
- AWS pricing calculator
- Cost explorer
- Billing dashboards
5. Test & Optimize Over Time
- Launch pilot instances
- Load test & monitor with CloudWatch
- Switch between families as needed
Taking the time to fully analyze workload requirements and instance capabilities pays dividends in the long run. You‘ll maximize performance while optimizing cost efficiency.
Launching & Monitoring Your First EC2 Instance
Once you‘ve selected the appropriate EC2 instance type, it‘s time to launch.
Follow these steps to deploy your first EC2 instance:
- Sign into the AWS console and navigate to the EC2 dashboard
- Click “Launch Instance” then select your preconfigured AMI (OS image)
- Choose your instance type based on the technical checklist above
- Configure instance details – VPC, IAM roles, storage etc
- Add storage with EBS volumes if needed
- Setup security groups acting as a virtual firewall
- Review settings then click “Launch Instance”
- Select an existing key pair for SSH access or create a new one
- Connect & customize your instance via SSH to install applications
Once launched, you need to monitor the performance of your EC2 instance.
Fortunately, AWS provides a powerful tool called CloudWatch that automatically collects metrics from your instances and workloads.
Key EC2 performance metrics provided by CloudWatch include:
- Per-Instance CPU Utilization
- Network utilization metrics
- Disk throughput statistics
- Disk space utilization
- Customizable application-level metrics
Based on performance data and usage patterns over time, you may opt to switch instance families to achieve better cost/performance efficiency.
We‘ve just scratched the surface of everything EC2 offers when it comes to customizable cloud compute – but hopefully this guide gave you a solid overview of the 5 major instance types available and how to choose between them.
With the right instance powering your cloud workload, almost anything you can dream up becomes possible!
