Instances›AWS EC2›c5›c5.12xlarge
Compute
vCPUs48
Memory96 GiB
Mem / vCPU2.00 GiB
ProcessorXeon Platinum 8275L
Clock speed3.4 GHz
Architecturex86_64
Storage
TypeEBS only
Bandwidth9,500 Mbps
Throughput1187.5 MB/s
IOPS40,000
Networking
Performance12 Gigabit
Max ENIs8
IPv6Yes
GPUNone
Family sizes
c5.large2 vCPU · 4 GiB
c5.xlarge4 vCPU · 8 GiB
c5.2xlarge8 vCPU · 16 GiB
c5.4xlarge16 vCPU · 32 GiB
c5.9xlarge36 vCPU · 72 GiB
c5.12xlarge48 vCPU · 96 GiB
c5.18xlarge72 vCPU · 144 GiB
c5.24xlarge96 vCPU · 192 GiB
c5.metal96 vCPU · 192 GiB
c5.12xlarge

The c5.12xlarge is a compute-optimized AWS EC2 instance: 48 vCPU and 96 GiB of memory, 2.00 GiB per vCPU. In the name, "c" stands for compute, "5" is the generation and "12xlarge" is the size within the c5 family. It runs on Intel Xeon Platinum 8275L at 3.4 GHz, and AWS introduced it in June 2019. AWS has since shipped c6i, c7i, c8i and c9g; c6i.12xlarge is the direct replacement at this size, scoring 847,121 CoreMark/s against this instance's 789,311 — roughly 7% more throughput for the same vCPU count. No single Spot node covers 48 vCPU and 96 GiB, so the equivalent is a fleet: 3 × ch.vs1.2xlarge, 48 vCPU and 96 GiB in total, about 94% 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

c5.12xlarge gives you 48 vCPU and 96 GiB in a single machine. The largest comparable Spot node, ch.vs1.2xlarge, is 16 vCPU and 32 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 96 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$2.040$0.609$1.285$0.855$0.123
$1.917 savings
US Central, Chicagono AWS region$0.033
US Central, Dallasno AWS region$0.333
Hong Kong$2.592$1.633$1.120$0.123
$2.469 savings
Sydney, Australia$2.664$0.783$1.678$1.151$0.123
$2.541 savings
London, UK$2.424$0.340$1.527$1.047$0.393
$2.031 savings
US West, San Jose$2.544$0.687$1.603$1.099$0.006
$2.538 savings
US Central, Dallas 2no AWS region$0.366
US East, N. Virginia 2$2.040$0.609$1.285$0.855$0.486
$1.554 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 96 GiB of RAM
  • ●Parallel work that can occupy 48 vCPU
  • ●Network-heavy services — AWS rates this size at 12 Gigabit
  • ●Anything that shards cleanly across 3 nodes, which is how it maps onto Rackspace Spot
Avoid if
  • ●Starting a new deployment. c6i.12xlarge is the newer generation at this size.
  • ●The working set needs more than 96 GiB of RAM
  • ●GPU or FPGA acceleration is needed
  • ●Memory-hungry applications. A memory-optimized family gives more RAM per dollar.
  • ●More than 2.00 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.
Stop overpaying AWS. This compute costs $1,489/mo on AWS vs $90/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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