Instances›AWS EC2›r8gn›r8gn.48xlarge
Compute
vCPUs192
Memory1536 GiB
Mem / vCPU8.00 GiB
ProcessorGraviton4 Processor
Clock speed2.8 GHz
Architecturearm64
Storage
TypeEBS only
Bandwidth120,000 Mbps
Throughput15000 MB/s
IOPS480,000
Networking
Performance600 Gigabit
Max ENIs24
IPv6Yes
GPUNone
Family sizes
r8gn.medium1 vCPU · 8 GiB
r8gn.large2 vCPU · 16 GiB
r8gn.xlarge4 vCPU · 32 GiB
r8gn.2xlarge8 vCPU · 64 GiB
r8gn.4xlarge16 vCPU · 128 GiB
r8gn.8xlarge32 vCPU · 256 GiB
r8gn.12xlarge48 vCPU · 384 GiB
r8gn.16xlarge64 vCPU · 512 GiB
r8gn.24xlarge96 vCPU · 768 GiB
r8gn.metal-24xl96 vCPU · 768 GiB
r8gn.48xlarge192 vCPU · 1536 GiB
r8gn.metal-48xl192 vCPU · 1536 GiB
r8gn.48xlarge

r8gn.48xlarge is AWS's memory-optimized EC2 size at 192 vCPU and 1536 GiB. In the name, "r" stands for RAM, "8" is the generation, "gn" marks AWS Graviton (ARM) processors and enhanced networking and "48xlarge" is the size within the r8gn family. It runs on AWS Graviton4 Processor at 2.8 GHz, and AWS introduced it in September 2025. AWS has since shipped r9g; r9g.48xlarge is the direct replacement at this size. The closest Spot shape is mh.vs1.2xlarge at 16 vCPU, so this instance maps to 12 of them — 192 vCPU and 1536 GiB across the fleet, $17.49/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

r8gn.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 onlyr8gn.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$17.489$6.688$0.252
$17.237 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
  • ●In-memory caches such as Redis and Memcached
  • ●Large JVM heaps and application servers that hold state
  • ●OLAP and business intelligence query engines
  • ●Workloads that fit inside 1536 GiB of RAM
  • ●Parallel work that can occupy 192 vCPU
  • ●Network-heavy services — AWS rates this size at 600 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
  • ●The work is single-threaded. Most of these 192 vCPU would sit idle.
  • ●Local NVMe or instance-store disk is a hard requirement
  • ●GPU or FPGA acceleration is needed
  • ●CPU-bound work. You are paying for memory this workload will not use.
r8gn.48xlarge runs $12,767/mo on AWS on-demand. The 12-node equivalent on Rackspace Spot: $184/mo.
  • 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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