Instances›AWS EC2›r9g›r9g.48xlarge
Compute
vCPUs192
Memory1536 GiB
Mem / vCPU8.00 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
r9g.medium1 vCPU · 8 GiB
r9g.large2 vCPU · 16 GiB
r9g.xlarge4 vCPU · 32 GiB
r9g.2xlarge8 vCPU · 64 GiB
r9g.4xlarge16 vCPU · 128 GiB
r9g.8xlarge32 vCPU · 256 GiB
r9g.12xlarge48 vCPU · 384 GiB
r9g.16xlarge64 vCPU · 512 GiB
r9g.24xlarge96 vCPU · 768 GiB
r9g.48xlarge192 vCPU · 1536 GiB
r9g.metal-48xl192 vCPU · 1536 GiB
r9g.48xlarge

The r9g.48xlarge pairs 192 vCPU with 1536 GiB of RAM, the 8.00 GiB-per-vCPU ratio that marks a memory-optimized instance. In the name, "r" stands for RAM, "9" is the generation, "g" marks AWS Graviton (ARM) processors and "48xlarge" is the size within the r9g family. It runs on AWS Graviton5 Processor at 3.3 GHz, and AWS introduced it in August 2026. r9g is the current generation of the r family, so there is no newer AWS size to migrate to. Spot's node ladder tops out below this size, so r9g.48xlarge becomes 12 × mh.vs1.2xlarge (192 vCPU, 1536 GiB combined), $12.33/hr on AWS in US East (N. Virginia), from $0.252/hr on Rackspace Spot. 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

r9g.48xlarge gives you 192 vCPU and 1,536 GiB in a single machine. The largest comparable Spot node, mh.vs1.2xlarge, is 16 vCPU and 128 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 1,536 GiB in one process, it does not.

x86_64 onlyr9g.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$12.328$3.177$0.252
$12.076 savings
US Central, Chicagono AWS region$0.252
US Central, Dallasno AWS region$1.572
Hong Kong$0.252
Sydney, Australia$0.252
London, UK$1.572
US West, San Jose$0.024
US Central, Dallas 2no AWS region$2.904
When to use it
Good for
  • ●Large JVM heaps and application servers that hold state
  • ●OLAP and business intelligence query engines
  • ●Real-time analytics over hot datasets
  • ●Workloads that fit inside 1536 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 1536 GiB of RAM
  • ●You cannot rebuild x86-only binaries or vendor images for aarch64
  • ●CPU-bound work. You are paying for memory this workload will not use.
  • ●More than 8.00 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
$9,000/mo on AWS on-demand against $184/mo on Rackspace Spot for the 12-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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