Instances›AWS EC2›c9g›c9g.48xlarge
Compute
vCPUs192
Memory384 GiB
Mem / vCPU2.00 GiB
ProcessorGraviton5 Processor
Clock speed3.3 GHz
Architecturearm64
Storage
TypeEBS only
Bandwidth72,000 Mbps
Throughput9000 MB/s
IOPS288,000
Networking
Performance100 Gigabit
Max ENIs24
IPv6Yes
GPUNone
Family sizes
c9g.medium1 vCPU · 2 GiB
c9g.large2 vCPU · 4 GiB
c9g.xlarge4 vCPU · 8 GiB
c9g.2xlarge8 vCPU · 16 GiB
c9g.4xlarge16 vCPU · 32 GiB
c9g.8xlarge32 vCPU · 64 GiB
c9g.12xlarge48 vCPU · 96 GiB
c9g.16xlarge64 vCPU · 128 GiB
c9g.24xlarge96 vCPU · 192 GiB
c9g.48xlarge192 vCPU · 384 GiB
c9g.metal-48xl192 vCPU · 384 GiB
c9g.48xlarge

c9g.48xlarge is AWS's compute-optimized EC2 size at 192 vCPU and 384 GiB. In the name, "c" stands for compute, "9" is the generation, "g" marks AWS Graviton (ARM) processors and "48xlarge" is the size within the c9g family. It runs on AWS Graviton5 Processor at 3.3 GHz, and AWS introduced it in June 2026. c9g is the current generation of the c family, so there is no newer AWS size to migrate to. The closest Spot shape is ch.vs1.2xlarge at 16 vCPU, so this instance maps to 12 of them — 192 vCPU and 384 GiB across the fleet, 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

c9g.48xlarge gives you 192 vCPU and 384 GiB in a single machine. The largest comparable Spot node, ch.vs1.2xlarge, is 16 vCPU and 32 GiB, so the equivalent here is 12 nodes rather than one.

Spot runs as managed Kubernetes, so a 12-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 192 cores and 384 GiB in one process, it does not.

x86_64 onlyc9g.48xlarge is Graviton (arm64) and Rackspace Spot has no arm64 nodes, so you'd be moving to x86. You'll need x86 builds of your images, and per-core speed differs between the chips — worth testing before you decide how many nodes to run.
Pricing by region
1 hr
RegionAWS on-demandAWS Spot1-yr Reserved3-yr ReservedRackspace SpotYou save
US East, N. Virginia$8.346$2.644$0.492
$7.854 savings
US Central, Chicagono AWS region$0.132
US Central, Dallasno AWS region$1.332
Hong Kong$0.492
Sydney, Australia$0.492
London, UK$1.572
US West, San Jose$0.024
US Central, Dallas 2no AWS region$1.464
US East, N. Virginia 2$8.346$2.644$1.944
$6.402 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 384 GiB of RAM
  • ●Parallel work that can occupy 192 vCPU
  • ●Network-heavy services — AWS rates this size at 100 Gigabit
  • ●Anything that shards cleanly across 12 nodes, which is how it maps onto Rackspace Spot
Avoid if
  • ●The working set needs more than 384 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 192 vCPU would sit idle.
  • ●Local NVMe or instance-store disk is a hard requirement
Stop overpaying AWS. This compute costs $6,093/mo on AWS vs $359/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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