Instances›AWS EC2›c8a›c8a.12xlarge
Compute
vCPUs48
Memory96 GiB
Mem / vCPU2.00 GiB
ProcessorEPYC 9R45 Processor
Clock speedUp to 4.5 GHz
Architecturex86_64
Storage
TypeEBS only
Bandwidth15,000 Mbps
Throughput1875 MB/s
IOPS60,000
Networking
Performance22.5 Gigabit
Max ENIs12
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.12xlarge

The c8a.12xlarge pairs 48 vCPU with 96 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 "12xlarge" 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.12xlarge is the direct replacement at this size. Spot's node ladder tops out below this size, so c8a.12xlarge becomes 3 × ch.vs1.2xlarge (48 vCPU, 96 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.12xlarge gives you 48 vCPU and 96 GiB in a single machine. The largest comparable Spot node, ch.vs1.2xlarge, is 16 vCPU and 32 GiB, so the equivalent here is 3 nodes rather than one.

Spot runs as managed Kubernetes, so a 3-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 48 cores and 96 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$2.587$0.956$0.123
$2.463 savings
US Central, Chicagono AWS region$0.033
US Central, Dallasno AWS region$0.333
Hong Kong$0.123
Sydney, Australia$0.123
London, UK$0.393
US West, San Jose$0.006
US Central, Dallas 2no AWS region$0.366
US East, N. Virginia 2$2.587$0.956$0.486
$2.101 savings
When to use it
Good for
  • ●High-traffic web and API serving
  • ●Scientific modelling and simulation
  • ●Ad serving and real-time bidding
  • ●Workloads that fit inside 96 GiB of RAM
  • ●Parallel work that can occupy 48 vCPU
  • ●Network-heavy services — AWS rates this size at 22.5 Gigabit
  • ●Anything that shards cleanly across 3 nodes, which is how it maps onto Rackspace Spot
Avoid if
  • ●The working set needs more than 96 GiB of RAM
  • ●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 48 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.
$1,888/mo on AWS on-demand against $90/mo on Rackspace Spot for the 3-node equivalent — market-priced, not list-priced.
  • 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