Instances›AWS EC2›r5dn›r5dn.16xlarge
Compute
vCPUs64
Memory512 GiB
Mem / vCPU8.00 GiB
ProcessorXeon Platinum 8259
Clock speed3.1 GHz
Architecturex86_64
Storage
Type4 × 600 GB NVMe SSD
Bandwidth13,600 Mbps
Throughput1700 MB/s
IOPS60,000
Networking
Performance75 Gigabit
Max ENIs15
IPv6Yes
GPUNone
Family sizes
r5dn.large2 vCPU · 16 GiB
r5dn.xlarge4 vCPU · 32 GiB
r5dn.2xlarge8 vCPU · 64 GiB
r5dn.4xlarge16 vCPU · 128 GiB
r5dn.8xlarge32 vCPU · 256 GiB
r5dn.12xlarge48 vCPU · 384 GiB
r5dn.16xlarge64 vCPU · 512 GiB
r5dn.24xlarge96 vCPU · 768 GiB
r5dn.metal96 vCPU · 768 GiB
r5dn.16xlarge

r5dn.16xlarge is AWS's memory-optimized EC2 size at 64 vCPU and 512 GiB. In the name, "r" stands for RAM, "5" is the generation, "dn" marks local NVMe storage and enhanced networking and "16xlarge" is the size within the r5dn family. It runs on Intel Xeon Platinum 8259 (Cascade Lake) at 3.1 GHz, and AWS introduced it in October 2019. AWS has since shipped r6i, r7i, r8i and r9g; r6i.16xlarge is the direct replacement at this size. 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, $5.34/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

r5dn.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.

No local diskr5dn.16xlarge comes with 4 × 600 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$5.344$1.318$3.367$2.176$0.084
$5.260 savings
US Central, Chicagono AWS region$0.084
US Central, Dallasno AWS region$0.524
Hong Kong$0.084
Sydney, Australia$6.528$2.832$4.113$2.672$0.084
$6.444 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
  • ●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 512 GiB of RAM
  • ●Jobs that want 4 × 600 GB of local NVMe scratch space
  • ●Network-heavy services — AWS rates this size at 75 Gigabit
  • ●Anything that shards cleanly across 4 nodes, which is how it maps onto Rackspace Spot
Avoid if
  • ●Starting a new deployment. r6i.16xlarge is the newer generation at this size.
  • ●The working set needs more than 512 GiB of RAM
  • ●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.
  • ●GPU or FPGA acceleration is needed
  • ●CPU-bound work. You are paying for memory this workload will not use.
r5dn.16xlarge runs $3,901/mo on AWS on-demand. The 4-node equivalent on Rackspace Spot: $61/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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