Silicon Triangle
c7ic7ac7gc7i-flex

AWS C7 Generation: C7i vs C7a vs C7g vs C7i-flex

4th Gen Intel Xeon Sapphire Rapids vs AMD EPYC Genoa vs AWS Graviton3 vs Flex

The 7th generation compute-optimized tier represents AWS's modern flagship CPU battlefield. Compare processor clock speeds, CoreMark benchmark efficiency, vCPU costs, and memory bandwidth across Intel, AMD, and custom Graviton3 ARM silicon.

Architectural Verdict

C7g (Graviton3) delivers the highest CoreMark performance-per-dollar and lowest raw hourly price (~19% cheaper than C7i). C7a (AMD Genoa) leads on raw x86 single-thread throughput. C7i-flex offers a 5% discount over C7i for unconstrained burstable web services.

Open in Interactive Comparator →

1. Architectural & Silicon Specs Head-to-Head

Comparing underlying processor microarchitectures, memory ratios, and Nitro generation features using representative xlarge sizing.

c7ix86_64
C7I Compute Optimized
ProcessorIntel Xeon Scalable (Sapphire Rapids)
Clock Speed3.2 GHz
RAM / vCPU2.0 GiB/vCPU
Max Network50 Gbps
Max EBS IOPS240,000
AWS NitroSupported
Min Rate (c7i.xlarge)$0.1749/hr
Monthly Est.$127.71/mo
Cost per vCPU$0.0437/hr
Cost per GiB RAM$0.0219/hr
CoreMark Benchmark97,652
CoreMark / $558,203
Price Index85% of highest
Save 15% vs most expensive
Compute / $ Value55% of leader
Browse all 9 c7i sizes →
c7ax86_64
C7A Compute Optimized
ProcessorAMD EPYC 9R14 Processor
Clock SpeedUp to 3.7 GHz
RAM / vCPU2.0 GiB/vCPU
Max Network50 Gbps
Max EBS IOPS240,000
AWS NitroSupported
Min Rate (c7a.xlarge)$0.2053/hr
Monthly Est.$149.85/mo
Cost per vCPU$0.0513/hr
Cost per GiB RAM$0.0257/hr
CoreMark Benchmark133,082
CoreMark / $648,295
Price Index100% of highest
Compute / $ Value64% of leader
Browse all 11 c7a sizes →
c7gARM64 (Graviton)
C7G Compute Optimized
ProcessorAWS Graviton3 Processor
Clock Speed2.5 GHz
RAM / vCPU2.0 GiB/vCPU
Max Network30 Gbps
Max EBS IOPS80,000
AWS NitroSupported
Min Rate (c7g.xlarge)$0.0982/hr
Monthly Est.$71.69/mo
Cost per vCPU$0.0245/hr
Cost per GiB RAM$0.0123/hr
CoreMark Benchmark99,782
CoreMark / $1,016,110
Price IndexLowest Cost
Save 52% vs most expensive
Compute / $ Value100% (Leader)
Browse all 8 c7g sizes →
c7i-flexx86_64
C7I-FLEX Compute Optimized
ProcessorIntel Xeon Scalable (Sapphire Rapids)
Clock Speed3.2 GHz
RAM / vCPU2.0 GiB/vCPU
Max NetworkUp to 25 Gbps
Max EBS IOPS80,000
AWS NitroSupported
Min Rate (c7i-flex.xlarge)$0.1662/hr
Monthly Est.$121.32/mo
Cost per vCPU$0.0415/hr
Cost per GiB RAM$0.0208/hr
CoreMark Benchmark81,045
CoreMark / $487,665
Price Index81% of highest
Save 19% vs most expensive
Compute / $ Value48% of leader
Browse all 7 c7i-flex sizes →

2. Side-by-Side Sizing & Pricing Matrix

Direct price and benchmark comparison across matching instance tiers in the lowest-cost region. Lowest hourly cost in each row is highlighted in green.

Size TiervCPUMemoryc7iLinux Ratec7aLinux Ratec7gLinux Ratec7i-flexLinux Rate
.medium12 GB—
$0.0513/hr
$37.5/mo+109%
$0.0245/hr
$17.9/moLowest Cost
—
.large24 GB
$0.0875/hr
$63.9/mo+78%
$0.1026/hr
$74.9/mo+109%
$0.0491/hr
$35.8/moLowest Cost
$0.0831/hr
$60.7/mo+69%
.xlarge48 GB
$0.1749/hr
$127.7/mo+78%
$0.2053/hr
$149.9/mo+109%
$0.0982/hr
$71.7/moLowest Cost
$0.1662/hr
$121.3/mo+69%
.2xlarge816 GB
$0.3499/hr
$255.4/mo+78%
$0.4106/hr
$299.7/mo+109%
$0.1963/hr
$143.3/moLowest Cost
$0.3324/hr
$242.6/mo+69%
.4xlarge1632 GB
$0.6998/hr
$510.8/mo+78%
$0.8211/hr
$599.4/mo+109%
$0.3926/hr
$286.6/moLowest Cost
$0.6648/hr
$485.3/mo+69%
.8xlarge3264 GB
$1.3995/hr
$1021.6/mo+78%
$1.6422/hr
$1198.8/mo+109%
$0.7853/hr
$573.3/moLowest Cost
$1.3295/hr
$970.6/mo+69%
.12xlarge4896 GB
$2.0993/hr
$1532.5/mo+78%
$2.4634/hr
$1798.3/mo+109%
$1.1779/hr
$859.9/moLowest Cost
$1.9943/hr
$1455.9/mo+69%
.16xlarge64128 GB
$2.7990/hr
$2043.3/mo+78%
$3.2845/hr
$2397.7/mo+109%
$1.5706/hr
$1146.5/moLowest Cost
$2.6591/hr
$1941.1/mo+69%
.24xlarge96192 GB
$4.1986/hr
$3064.9/moLowest Cost
$4.9267/hr
$3596.5/mo+17%
——
.32xlarge128256 GB—
$6.5690/hr
$4795.3/moLowest Cost
——
.48xlarge192384 GB
$8.3971/hr
$6129.9/moLowest Cost
$9.8534/hr
$7193.0/mo+17%
——

3. Workload Decision Framework

Clear, actionable rules on when each family wins based on workload profile, runtime language, and licensing boundaries.

Recommended:C7g (Graviton3)
When: Workloads can run on Linux ARM64 containers (Go, Rust, Python, Node, Java 17+)
Why: Lowest hourly price and superior energy efficiency with native bfloat16 and DDR5 memory.
Recommended:C7a (AMD Genoa)
When: Maximum single-core and floating-point performance on standard x86_64 binaries
Why: Zen 4 architecture with up to 3.7 GHz all-core boost and strong memory bandwidth.
Recommended:C7i (Intel Sapphire Rapids)
When: Strict Intel AVX-512 / AMX matrix acceleration requirements or legacy Windows x86
Why: Full support for Intel Advanced Matrix Extensions (AMX) and Intel Deep Learning Boost.
Recommended:C7i-flex
When: General CPU web workloads with moderate utilization looking for instant x86 savings
Why: 5% baseline discount over standard C7i without rewriting binaries for ARM64.

4. Architecture & Migration Considerations

Technical caveats, instruction set differences, and compiler flags to know before deploying.

DDR5 Memory Transition

All C7 families transition to high-speed DDR5 memory, delivering up to 50% more memory bandwidth compared to 6th generation DDR4 instances.

Nitro v5 Architecture

Built on AWS Nitro Cards v5, offering lower packet latency, faster EBS IOPS scaling, and dedicated hardware cryptographic acceleration.

5. Related Architecture Comparisons

Explore adjacent generational comparisons and silicon trade-offs.

Generational Evolution

C4 vs C5 vs C6i vs C7i vs C7g

Tracking a decade of compute optimization from Xen hypervisors to Graviton3 Nitro

View comparison →Generational Evolution

A1 vs C6g vs C7g vs C8g

The complete journey of AWS custom ARM silicon from experimental A1 to Graviton4

View comparison →Generational Evolution

C5 vs C6i vs C7i

Skylake/Cascade Lake vs Ice Lake vs Sapphire Rapids Intel compute

View comparison →