AWS News Blog

New C5n Instances with 100 Gbps Networking

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We launched the powerful, compute-intensive C5 instances last year, and followed up with the C5d instances earlier this year with the addition of local NVMe storage. Both instances are built on the AWS Nitro system and are powered by AWS-custom 3.0 Ghz Intel® Xeon® Platinum 8000 series processors. They are designed for compute-heavy applications such as batch processing, distributed analytics, high-performance computing (HPC), ad serving, highly scalable multiplayer gaming, and video encoding.

New 100 Gbps Networking
Today we are adding an even more powerful variant, the C5n instance. With up to 100 Gbps of network bandwidth, your simulations, in-memory caches, data lakes, and other communication-intensive applications will run better than ever. Here are the specs:

Instance Name vCPUs
EBS Bandwidth Network Bandwidth
c5n.large 2 5.25 GiB Up to 3.5 Gbps Up to 25 Gbps
c5n.xlarge 4 10.5 GiB Up to 3.5 Gbps Up to 25 Gbps
c5n.2xlarge 8 21 GiB Up to 3.5 Gbps Up to 25 Gbps
c5n.4xlarge 16 42 GiB 3.5 Gbps Up to 25 Gbps
c5n.9xlarge 36 96 GiB 7 Gbps 50 Gbps
c5n.18xlarge 72 192 GiB 14 Gbps 100 Gbps

The Nitro Hypervisor allows the full range of C5n instances to deliver performance that is just about indistinguishable from bare metal. Other AWS Nitro System components, including the Nitro Security Chip, hardware EBS processing, and hardware support for the software defined network inside of each VPC also enhance performance.

Each vCPU is a hardware hyperthread on the Intel Xeon Platinum 8000 series processor. You get full control over the C-states on the two largest sizes, allowing you to run a single core at up to 3.5 Ghz using Intel Turbo Boost Technology.

The new instances also feature a higher amount of memory per core, putting them in the current “sweet spot” for HPC applications that work most efficiently when there’s at least 4 GiB of memory for each core. The instances also benefit from some internal improvements that boost memory access speed by up to 19% in comparison to the C5 and C5d instances.

It’s All About the Network
Now let’s get to the big news!

The C5n instances incorporate the fourth generation of our custom Nitro hardware, allowing the high-end instances to provide up to 100 Gbps of network throughput, along with a higher ceiling on packets per second. The Elastic Network Interface (ENI) on the C5n uses up to 32 queues (in comparison to 8 on the C5 and C5d), allowing the packet processing workload to be better distributed across all available vCPUs. The ability to push more packets per second will make these instances a great fit for network appliances such as firewalls, routers, and 5G cellular infrastructure.

In order to make the most of the available network bandwidth, you need to be using the latest Elastic Network Adapter (ENA) drivers (available in the latest Amazon Linux, Red Hat 7.6, and Ubuntu AMIs, and in the upstream Linux kernel) and you need to make use of multiple traffic flows. Flows within a Placement Group can reach 10 Gbps; the rest can reach 5 Gbps. When using multiple flows on the high-end instances, you can transfer 100 Gbps between EC2 instances in the same region (within or across AZs), S3 buckets, and AWS services such as Amazon Relational Database Service (RDS), Amazon ElastiCache, and Amazon EMR.

Available Now
C5n instances are available now in the US East (N. Virginia), US East (Ohio), US West (Oregon), Europe (Ireland), and AWS GovCloud (US-West) Regions and you can launch one (or an entire cluster of them) today in On-Demand, Reserved Instance, Spot, Dedicated Host, or Dedicated Instance form.


Jeff Barr

Jeff Barr

Jeff Barr is Chief Evangelist for AWS. He started this blog in 2004 and has been writing posts just about non-stop ever since.