Instances›AWS EC2›c6gd›c6gd.16xlarge
Compute
vCPUs64
Memory128 GiB
Mem / vCPU2.00 GiB
ProcessorGraviton2 Processor
Clock speed2.5 GHz
Architecturearm64
Storage
Type2 × 1,900 GB NVMe SSD
Bandwidth19,000 Mbps
Throughput2375 MB/s
IOPS80,000
Networking
Performance25 Gigabit
Max ENIs15
IPv6Yes
GPUNone
Family sizes
c6gd.medium1 vCPU · 2 GiB
c6gd.large2 vCPU · 4 GiB
c6gd.xlarge4 vCPU · 8 GiB
c6gd.2xlarge8 vCPU · 16 GiB
c6gd.4xlarge16 vCPU · 32 GiB
c6gd.8xlarge32 vCPU · 64 GiB
c6gd.12xlarge48 vCPU · 96 GiB
c6gd.16xlarge64 vCPU · 128 GiB
c6gd.metal64 vCPU · 128 GiB
c6gd.16xlarge

c6gd.16xlarge is AWS's compute-optimized EC2 size at 64 vCPU and 128 GiB. In the name, "c" stands for compute, "6" is the generation, "gd" marks AWS Graviton (ARM) processors and local NVMe storage and "16xlarge" is the size within the c6gd family. It runs on AWS Graviton2 Processor at 2.5 GHz, and AWS introduced it in July 2020. AWS has since shipped c7gd, c8gd and c9gd; c7gd.16xlarge is the direct replacement at this size, scoring 1,579,467 CoreMark/s against this instance's 1,243,765 — roughly 27% more throughput for the same vCPU count. The closest Spot shape is ch.vs1.2xlarge at 16 vCPU, so this instance maps to 4 of them — 64 vCPU and 128 GiB across the fleet, about 93% 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

c6gd.16xlarge gives you 64 vCPU and 128 GiB in a single machine. The largest comparable Spot node, ch.vs1.2xlarge, is 16 vCPU and 32 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 128 GiB in one process, it does not.

x86_64 onlyc6gd.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 diskc6gd.16xlarge comes with 2 × 1,900 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$2.458$0.463$1.548$1.062$0.164
$2.294 savings
US Central, Chicagono AWS region$0.044
US Central, Dallasno AWS region$0.444
Hong Kong$0.164
Sydney, Australia$3.232$0.671$2.016$1.382$0.164
$3.068 savings
London, UK$2.944$0.308$1.855$1.272$0.524
$2.420 savings
US West, San Jose$3.072$0.397$1.949$1.313$0.008
$3.064 savings
US Central, Dallas 2no AWS region$0.488
US East, N. Virginia 2$2.458$0.463$1.548$1.062$0.648
$1.810 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 128 GiB of RAM
  • ●Jobs that want 2 × 1,900 GB of local NVMe scratch space
  • ●Network-heavy services — AWS rates this size at 25 Gigabit
  • ●Anything that shards cleanly across 4 nodes, which is how it maps onto Rackspace Spot
Avoid if
  • ●Starting a new deployment. c7gd.16xlarge is the newer generation at this size.
  • ●The working set needs more than 128 GiB of RAM
  • ●You cannot rebuild x86-only binaries or vendor images for aarch64
  • ●The work is single-threaded. Most of these 64 vCPU would sit idle.
  • ●GPU or FPGA acceleration is needed
  • ●Memory-hungry applications. A memory-optimized family gives more RAM per dollar.
Stop overpaying AWS. This compute costs $1,794/mo on AWS vs $120/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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