Instances›AWS EC2›c8a›c8a.16xlarge
Compute
vCPUs64
Memory128 GiB
Mem / vCPU2.00 GiB
ProcessorEPYC 9R45 Processor
Clock speedUp to 4.5 GHz
Architecturex86_64
Storage
TypeEBS only
Bandwidth20,000 Mbps
Throughput2500 MB/s
IOPS80,000
Networking
Performance30 Gigabit
Max ENIs16
IPv6Yes
GPUNone
Family sizes
c8a.medium1 vCPU · 2 GiB
c8a.large2 vCPU · 4 GiB
c8a.xlarge4 vCPU · 8 GiB
c8a.2xlarge8 vCPU · 16 GiB
c8a.4xlarge16 vCPU · 32 GiB
c8a.8xlarge32 vCPU · 64 GiB
c8a.12xlarge48 vCPU · 96 GiB
c8a.16xlarge64 vCPU · 128 GiB
c8a.24xlarge96 vCPU · 192 GiB
c8a.metal-24xl96 vCPU · 192 GiB
c8a.48xlarge192 vCPU · 384 GiB
c8a.metal-48xl192 vCPU · 384 GiB
c8a.16xlarge

The c8a.16xlarge pairs 64 vCPU with 128 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, "a" marks AMD processors and "16xlarge" is the size within the c8a family. It runs on AMD EPYC 9R45 Processor at Up to 4.5 GHz, and AWS introduced it in December 2025. AWS has since shipped c9g; c9g.16xlarge is the direct replacement at this size. Spot's node ladder tops out below this size, so c8a.16xlarge becomes 4 × ch.vs1.2xlarge (64 vCPU, 128 GiB combined), about 95% below the US East (N. Virginia) on-demand rate. Spot delivers compute as managed Kubernetes, so a node pool of that size is the native shape of the answer rather than a workaround — provided the workload scales horizontally.

Match qualityScale-out match

c8a.16xlarge gives you 64 vCPU and 128 GiB in a single machine. The largest comparable Spot node, ch.vs1.2xlarge, is 16 vCPU and 32 GiB, so the equivalent here is 4 nodes rather than one.

Spot runs as managed Kubernetes, so a 4-node pool is the normal way to run things rather than a workaround. If your workload already sits behind a load balancer, a queue or a scheduler, it spreads across them without changes. If it needs all 64 cores and 128 GiB in one process, it does not.

Pricing by region
1 hr
RegionAWS on-demandAWS Spot1-yr Reserved3-yr ReservedRackspace SpotYou save
US East, N. Virginia$3.449$0.943$0.164
$3.285 savings
US Central, Chicagono AWS region$0.044
US Central, Dallasno AWS region$0.444
Hong Kong$0.164
Sydney, Australia$0.164
London, UK$0.524
US West, San Jose$0.008
US Central, Dallas 2no AWS region$0.488
US East, N. Virginia 2$3.449$0.943$0.648
$2.801 savings
When to use it
Good for
  • ●Ad serving and real-time bidding
  • ●Game servers and matchmaking
  • ●Batch processing and CI/CD runners
  • ●Workloads that fit inside 128 GiB of RAM
  • ●Parallel work that can occupy 64 vCPU
  • ●Network-heavy services — AWS rates this size at 30 Gigabit
  • ●Anything that shards cleanly across 4 nodes, which is how it maps onto Rackspace Spot
Avoid if
  • ●The working set needs more than 128 GiB of RAM
  • ●The work is single-threaded. Most of these 64 vCPU would sit idle.
  • ●Local NVMe or instance-store disk is a hard requirement
  • ●GPU or FPGA acceleration is needed
  • ●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
c8a.16xlarge runs $2,517/mo on AWS on-demand. The 4-node equivalent on Rackspace Spot: $120/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.
Build your Cloudspace
Frequently asked questions