Instances›AWS EC2›r6i›r6i.12xlarge
Compute
vCPUs48
Memory384 GiB
Mem / vCPU8.00 GiB
ProcessorXeon 8375C
Clock speed3.5 GHz
Architecturex86_64
Storage
TypeEBS only
Bandwidth15,000 Mbps
Throughput1875 MB/s
IOPS60,000
Networking
Performance18.75 Gigabit
Max ENIs8
IPv6Yes
GPUNone
Family sizes
r6i.large2 vCPU · 16 GiB
r6i.xlarge4 vCPU · 32 GiB
r6i.2xlarge8 vCPU · 64 GiB
r6i.4xlarge16 vCPU · 128 GiB
r6i.8xlarge32 vCPU · 256 GiB
r6i.12xlarge48 vCPU · 384 GiB
r6i.16xlarge64 vCPU · 512 GiB
r6i.24xlarge96 vCPU · 768 GiB
r6i.32xlarge128 vCPU · 1024 GiB
r6i.metal128 vCPU · 1024 GiB
r6i.12xlarge

r6i.12xlarge is AWS's memory-optimized EC2 size at 48 vCPU and 384 GiB. In the name, "r" stands for RAM, "6" is the generation, "i" marks Intel processors and "12xlarge" is the size within the r6i family. It runs on Intel Xeon 8375C (Ice Lake) at 3.5 GHz, and AWS introduced it in November 2021. AWS has since shipped r7i, r8i and r9g; r7i.12xlarge is the direct replacement at this size, scoring 1,058,396 CoreMark/s against this instance's 845,256 — roughly 25% more throughput for the same vCPU count. The closest Spot shape is mh.vs1.2xlarge at 16 vCPU, so this instance maps to 3 of them — 48 vCPU and 384 GiB across the fleet, $3.02/hr on AWS in US East (N. Virginia), from $0.063/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

r6i.12xlarge gives you 48 vCPU and 384 GiB in a single machine. The largest comparable Spot node, mh.vs1.2xlarge, is 16 vCPU and 128 GiB, so the equivalent here is 3 nodes rather than one.

Spot runs as managed Kubernetes, so a 3-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 48 cores and 384 GiB in one process, it does not.

Pricing by region
1 hr
RegionAWS on-demandAWS Spot1-yr Reserved3-yr ReservedRackspace SpotYou save
US East, N. Virginia$3.024$1.053$2.000$1.372$0.063
$2.961 savings
US Central, Chicagono AWS region$0.063
US Central, Dallasno AWS region$0.393
Hong Kong$4.008$2.525$1.732$0.063
$3.945 savings
Sydney, Australia$3.624$1.335$2.395$1.647$0.063
$3.561 savings
London, UK$3.552$0.595$2.355$1.606$0.393
$3.159 savings
US West, San Jose$3.360$0.717$2.223$1.524$0.006
$3.354 savings
US Central, Dallas 2no AWS region$0.726
When to use it
Good for
  • ●OLAP and business intelligence query engines
  • ●Real-time analytics over hot datasets
  • ●Database instances that keep the working set in RAM
  • ●Workloads that fit inside 384 GiB of RAM
  • ●Parallel work that can occupy 48 vCPU
  • ●Network-heavy services — AWS rates this size at 18.75 Gigabit
  • ●Anything that shards cleanly across 3 nodes, which is how it maps onto Rackspace Spot
Avoid if
  • ●Starting a new deployment. r7i.12xlarge is the newer generation at this size.
  • ●The working set needs more than 384 GiB of RAM
  • ●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 48 vCPU would sit idle.
  • ●Local NVMe or instance-store disk is a hard requirement
$2,208/mo on AWS on-demand against $46/mo on Rackspace Spot for the 3-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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