Instances›AWS EC2›c8gn›c8gn.4xlarge
Compute
vCPUs16
Memory32 GiB
Mem / vCPU2.00 GiB
ProcessorGraviton4 Processor
Clock speed2.8 GHz
Architecturearm64
Storage
TypeEBS only
Bandwidth10,000 Mbps
Throughput1250 MB/s
IOPS40,000
Networking
Performance50 Gigabit
Max ENIs8
IPv6Yes
GPUNone
Family sizes
c8gn.medium1 vCPU · 2 GiB
c8gn.large2 vCPU · 4 GiB
c8gn.xlarge4 vCPU · 8 GiB
c8gn.2xlarge8 vCPU · 16 GiB
c8gn.4xlarge16 vCPU · 32 GiB
c8gn.8xlarge32 vCPU · 64 GiB
c8gn.12xlarge48 vCPU · 96 GiB
c8gn.16xlarge64 vCPU · 128 GiB
c8gn.24xlarge96 vCPU · 192 GiB
c8gn.metal-24xl96 vCPU · 192 GiB
c8gn.48xlarge192 vCPU · 384 GiB
c8gn.metal-48xl192 vCPU · 384 GiB
c8gn.4xlarge

The c8gn.4xlarge pairs 16 vCPU with 32 GiB of RAM, the 2.00 GiB-per-vCPU ratio that marks a compute-optimized instance. In the name, "c" stands for compute, "8" is the generation, "gn" marks AWS Graviton (ARM) processors and enhanced networking and "4xlarge" is the size within the c8gn family. It runs on AWS Graviton4 Processor at 2.8 GHz, and AWS introduced it in June 2025. AWS has since shipped c9g; c9g.4xlarge is the direct replacement at this size, scoring 576,473 CoreMark/s against this instance's 470,727 — roughly 22% more throughput for the same vCPU count. ch.vs1.2xlarge on Rackspace Spot lines up one-for-one: 16 vCPU and 32 GiB, $0.948/hr on AWS in US East (N. Virginia), from $0.041/hr on Rackspace Spot.

Match qualityx86 substitution

c8gn.4xlarge is Graviton (arm64). Rackspace Spot does not have arm64 servers, so ch.vs1.2xlarge is an x86_64 substitute with similar specs.

You will need x86 builds of your container images. Most software rebuilds without changes, but anything with compiled native code needs a real rebuild rather than a retag. Speed per core also differs between the two chips, so it is worth testing before deciding how many nodes to run.

Pricing by region
1 hr
RegionAWS on-demandAWS Spot1-yr Reserved3-yr ReservedRackspace SpotYou save
US East, N. Virginia$0.948$0.288$0.041
$0.907 savings
US Central, Chicagono AWS region$0.011
US Central, Dallasno AWS region$0.111
Hong Kong$1.255$0.041
$1.214 savings
Sydney, Australia$1.238$0.292$0.041
$1.197 savings
London, UK$1.123$0.200$0.131
$0.992 savings
US West, San Jose$1.185$0.399$0.002
$1.183 savings
US Central, Dallas 2no AWS region$0.122
US East, N. Virginia 2$0.948$0.288$0.162
$0.786 savings
When to use it
Good for
  • ●Video encoding and transcoding
  • ●High-traffic web and API serving
  • ●Scientific modelling and simulation
  • ●Workloads that fit inside 32 GiB of RAM
  • ●Parallel work that can occupy 16 vCPU
  • ●Network-heavy services — AWS rates this size at 50 Gigabit
Avoid if
  • ●The working set needs more than 32 GiB of RAM
  • ●You cannot rebuild x86-only binaries or vendor images for aarch64
  • ●Memory-hungry applications. A memory-optimized family gives more RAM per dollar.
  • ●More than 2.00 GiB of RAM per vCPU is needed — that ratio is fixed for the whole family
  • ●The work is single-threaded. Most of these 16 vCPU would sit idle.
  • ●Local NVMe or instance-store disk is a hard requirement
c8gn.4xlarge runs $692/mo on AWS on-demand. The equivalent on Rackspace Spot: $30/mo.
  • Spot sells spare capacity at market prices. It is the cheapest compute on the internet.
  • Prices are set by supply and demand. You pay what the market decides.
  • Compute is delivered as fully managed Kubernetes. All infrastructure is taken care of.
  • Egress costs $0.01/GB after the free allowance. AWS charges $0.09/GB.
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