Instances›AWS EC2›c8i›c8i.12xlarge
Compute
vCPUs48
Memory96 GiB
Mem / vCPU2.00 GiB
ProcessorXeon Scalable
Clock speed3.9 GHz
Architecturex86_64
Storage
TypeEBS only
Bandwidth15,000 Mbps
Throughput1875 MB/s
IOPS60,000
Networking
Performance22.5 Gigabit
Max ENIs12
IPv6Yes
GPUNone
Family sizes
c8i.large2 vCPU · 4 GiB
c8i.xlarge4 vCPU · 8 GiB
c8i.2xlarge8 vCPU · 16 GiB
c8i.4xlarge16 vCPU · 32 GiB
c8i.8xlarge32 vCPU · 64 GiB
c8i.12xlarge48 vCPU · 96 GiB
c8i.16xlarge64 vCPU · 128 GiB
c8i.24xlarge96 vCPU · 192 GiB
c8i.32xlarge128 vCPU · 256 GiB
c8i.48xlarge192 vCPU · 384 GiB
c8i.metal-48xl192 vCPU · 384 GiB
c8i.96xlarge384 vCPU · 768 GiB
c8i.metal-96xl384 vCPU · 768 GiB
c8i.12xlarge

c8i.12xlarge is AWS's compute-optimized EC2 size at 48 vCPU and 96 GiB. In the name, "c" stands for compute, "8" is the generation, "i" marks Intel processors and "12xlarge" is the size within the c8i family. It runs on Intel Xeon Scalable (Granite Rapids) at 3.9 GHz, and AWS introduced it in October 2025. AWS has since shipped c9g; c9g.12xlarge is the direct replacement at this size, scoring 1,639,344 CoreMark/s against this instance's 1,138,115 — roughly 44% more throughput for the same vCPU count. The closest Spot shape is ch.vs1.2xlarge at 16 vCPU, so this instance maps to 3 of them — 48 vCPU and 96 GiB across the fleet, 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

c8i.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$2.249$0.822$0.123
$2.126 savings
US Central, Chicagono AWS region$0.033
US Central, Dallasno AWS region$0.333
Hong Kong$0.123
Sydney, Australia$2.937$0.869$0.123
$2.814 savings
London, UK$2.672$0.719$0.393
$2.279 savings
US West, San Jose$2.805$0.693$0.006
$2.799 savings
US Central, Dallas 2no AWS region$0.366
US East, N. Virginia 2$2.249$0.822$0.486
$1.763 savings
When to use it
Good for
  • ●Scientific modelling and simulation
  • ●Ad serving and real-time bidding
  • ●Game servers and matchmaking
  • ●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
  • ●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
  • ●The work is single-threaded. Most of these 48 vCPU would sit idle.
  • ●Local NVMe or instance-store disk is a hard requirement
$1,642/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.
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