Instances›AWS EC2›i4g›i4g.16xlarge
Compute
vCPUs64
Memory512 GiB
Mem / vCPU8.00 GiB
ProcessorGraviton2 Processor
Clock speed2.5 GHz
Architecturearm64
Storage
Type4 × 3,750 GB NVMe SSD
Bandwidth20,000 Mbps
Throughput2500 MB/s
IOPS80,000
Networking
Performance37.5 Gigabit
Max ENIs15
IPv6Yes
GPUNone
Family sizes
i4g.large2 vCPU · 16 GiB
i4g.xlarge4 vCPU · 32 GiB
i4g.2xlarge8 vCPU · 64 GiB
i4g.4xlarge16 vCPU · 128 GiB
i4g.8xlarge32 vCPU · 256 GiB
i4g.16xlarge64 vCPU · 512 GiB
i4g.16xlarge

i4g.16xlarge is AWS's storage-optimized EC2 size at 64 vCPU and 512 GiB. In the name, "i" is I/O, meaning local storage, "4" is the generation, "g" marks AWS Graviton (ARM) processors and "16xlarge" is the size within the i4g family. It runs on AWS Graviton2 Processor at 2.5 GHz, and AWS introduced it in May 2023. AWS has since shipped i7i and i8g; i7i.16xlarge is the direct replacement at this size, scoring 1,403,971 CoreMark/s against this instance's 1,271,186 — roughly 10% more throughput for the same vCPU count. The closest Spot shape is mh.vs1.2xlarge at 16 vCPU, so this instance maps to 4 of them — 64 vCPU and 512 GiB across the fleet, $4.94/hr on AWS in US East (N. Virginia), from $0.084/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

i4g.16xlarge gives you 64 vCPU and 512 GiB in a single machine. The largest comparable Spot node, mh.vs1.2xlarge, is 16 vCPU and 128 GiB, so the equivalent here is 4 nodes rather than one.

Spot runs as managed Kubernetes, so a 4-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 64 cores and 512 GiB in one process, it does not.

x86_64 onlyi4g.16xlarge 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.
No local diski4g.16xlarge comes with 4 × 3,750 GB NVMe SSD attached to the machine. Spot nodes use network storage only, so that disk doesn't come with it. If you were using it as fast scratch space, you'd move to a persistent volume or object storage, which are slower to read.
Pricing by region
1 hr
RegionAWS on-demandAWS Spot1-yr Reserved3-yr ReservedRackspace SpotYou save
US East, N. Virginia$4.942$1.360$3.207$2.286$0.084
$4.858 savings
US Central, Chicagono AWS region$0.084
US Central, Dallasno AWS region$0.524
Hong Kong$0.084
Sydney, Australia$5.924$1.004$3.867$2.743$0.084
$5.840 savings
London, UK$0.524
US West, San Jose$0.008
US Central, Dallas 2no AWS region$0.968
When to use it
Good for
  • ●Distributed file systems and search indexes
  • ●Transactional databases with heavy random I/O
  • ●Streaming ingest that spools to local disk
  • ●Workloads that fit inside 512 GiB of RAM
  • ●Jobs that want 4 × 3,750 GB of local NVMe scratch space
  • ●Network-heavy services — AWS rates this size at 37.5 Gigabit
  • ●Anything that shards cleanly across 4 nodes, which is how it maps onto Rackspace Spot
Avoid if
  • ●Starting a new deployment. i7i.16xlarge is the newer generation at this size.
  • ●The working set needs more than 512 GiB of RAM
  • ●You cannot rebuild x86-only binaries or vendor images for aarch64
  • ●Workloads that never touch local disk. The instance-store premium is wasted.
  • ●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 64 vCPU would sit idle.
$3,608/mo on AWS on-demand against $61/mo on Rackspace Spot for the 4-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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