Instances›AWS EC2›c7i-flex›c7i-flex.12xlarge
Compute
vCPUs48
Memory96 GiB
Mem / vCPU2.00 GiB
ProcessorXeon Scalable
Clock speed3.2 GHz
Architecturex86_64
Storage
TypeEBS only
Bandwidth15,000 Mbps
Throughput1875 MB/s
IOPS60,000
Networking
PerformanceUp to 18.75 Gigabit
Max ENIs8
IPv6Yes
GPUNone
Family sizes
c7i-flex.large2 vCPU · 4 GiB
c7i-flex.xlarge4 vCPU · 8 GiB
c7i-flex.2xlarge8 vCPU · 16 GiB
c7i-flex.4xlarge16 vCPU · 32 GiB
c7i-flex.8xlarge32 vCPU · 64 GiB
c7i-flex.12xlarge48 vCPU · 96 GiB
c7i-flex.16xlarge64 vCPU · 128 GiB
c7i-flex.12xlarge

The c7i-flex.12xlarge is a compute-optimized AWS EC2 instance: 48 vCPU and 96 GiB of memory, 2.00 GiB per vCPU. It runs on Intel Xeon Scalable (Sapphire Rapids) at 3.2 GHz, and AWS introduced it in January 2025. No single Spot node covers 48 vCPU and 96 GiB, so the equivalent is a fleet: 3 × ch.vs1.2xlarge, 48 vCPU and 96 GiB in total, about 94% 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

c7i-flex.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$2.035$0.509$1.346$0.896$0.123
$1.912 savings
US Central, Chicagono AWS region$0.033
US Central, Dallasno AWS region$0.333
Hong Kong$2.586$1.710$1.173$0.123
$2.463 savings
Sydney, Australia$2.657$0.838$1.754$1.207$0.123
$2.534 savings
London, UK$2.418$0.252$1.596$1.099$0.393
$2.025 savings
US West, San Jose$2.538$0.687$1.676$1.154$0.006
$2.532 savings
US Central, Dallas 2no AWS region$0.366
US East, N. Virginia 2$2.035$0.509$1.346$0.896$0.486
$1.549 savings
When to use it
Good for
  • ●Game servers and matchmaking
  • ●Batch processing and CI/CD runners
  • ●Video encoding and transcoding
  • ●Workloads that fit inside 96 GiB of RAM
  • ●Parallel work that can occupy 48 vCPU
  • ●Network-heavy services — AWS rates this size at Up to 18.75 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
  • ●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.
  • ●More than 2.00 GiB of RAM per vCPU is needed — that ratio is fixed for the whole family
Stop overpaying AWS. This compute costs $1,485/mo on AWS vs $90/mo on Rackspace Spot.
  • 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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