db.r8a.16xlargevsdb.r8g.16xlarge

db.r8g.16xlarge is 21% cheaper than db.r8a.16xlarge on demand in US East (N. Virginia), saving $1,469.34 a month. They use different processor architectures (x86_64 and arm64), so software built for one may need rebuilding to run on the other.

At a glancedb.r8a.16xlargedb.r8g.16xlarge
On-demand$9.661/hr$7.648/hr21% less
Lowest rate$7.729/hr1-yr savings plan, hourly commitment$6.118/hr21% less1-yr savings plan, hourly commitment
Size64 vCPUs, 512 GiB64 vCPUs, 512 GiB
Processor5th Generation AMD EPYCAWS Graviton4
Architecturex86_64arm64

Prices in US East (N. Virginia)

“Off” is the discount against each type’s own on-demand price. PostgreSQL, USD per hour.

Optiondb.r8a.16xlargedb.r8g.16xlargedb.r8g.16xlarge vs db.r8a.16xlarge
On-demandPay by the hour$9.661$7.648▼ 21%
1-yr reservedNo upfront—33% off$5.124—
3-yr reservedNo upfront—53% off$3.595—
1-yr savings planHourly commitment20% off$7.72920% off$6.118▼ 21%

Key differences

The biggest lead each one has.

Where db.r8a.16xlarge leads
Sustained clock4.5 GHz vs 2.8 GHz
61% higher
Where db.r8g.16xlarge leads
On-demand price$7.648 vs $9.661 per hour
21% cheaper

Specs

8 of 24 specs differ. Those are in bold.

Compute4 of 8 differdb.r8a.16xlargedb.r8g.16xlarge
vCPUs6464
Physical cores6464
Threads per core11
Architecturex86_64arm64
Processor5th Generation AMD EPYCAWS Graviton4
CPU makerAMDAWS
Sustained clock4.5 GHz2.8 GHz
BurstableNoNo
MemoryAll 1 matchdb.r8a.16xlargedb.r8g.16xlarge
Memory (GiB)512512
Networking1 of 3 differdb.r8a.16xlargedb.r8g.16xlarge
Network30000 Mbps30 Gigabit
Network baseline30 Gbps30 Gbps
Network peak30 Gbps30 Gbps
StorageAll 7 matchdb.r8a.16xlargedb.r8g.16xlarge
StorageEBS OnlyEBS Only
EBS baseline bandwidth20,000 Mbps20,000 Mbps
EBS max bandwidth20,000 Mbps20,000 Mbps
EBS baseline throughput2,500 MB/s2,500 MB/s
EBS max throughput2,500 MB/s2,500 MB/s
EBS baseline IOPS80,00080,000
EBS max IOPS80,00080,000
Instance details2 of 4 differdb.r8a.16xlargedb.r8g.16xlarge
Familyr8ar8g
CategoryMemory optimizedMemory optimized
Current generationYesYes
Normalization factor256128
Other1 of 1 differdb.r8a.16xlargedb.r8g.16xlarge
Hardware Basisr8a.16xlarger8g.16xlarge

On-demand prices by region

Cheapest for db.r8a.16xlarge first. PostgreSQL, USD per hour.

Regiondb.r8a.16xlargedb.r8g.16xlargeDifference
US East (N. Virginia)Used in summaryus-east-1$9.661$7.648▼ 21%
US East (Ohio)us-east-2$9.661$7.648▼ 21%
US West (Oregon)us-west-2$9.661$7.648▼ 21%
Canada (Central)ca-central-1$10.432$8.262▼ 21%
EU (Ireland)eu-west-1$10.819$8.576▼ 21%
Europe (Spain)eu-south-2$10.819$8.576▼ 21%
Asia Pacific (Tokyo)ap-northeast-1$11.594$9.184▼ 21%
EU (Frankfurt)eu-central-1$11.786$9.312▼ 21%

Keep exploring

Each type’s own page, and how it compares with others.

db.r8a.16xlargeMemory optimized, r8a family
db.r8a.16xlarge prices and specsEvery size in the r8a family

Compare db.r8a.16xlarge with

db.r8i.16xlargedb.m8a.16xlarge
db.r8g.16xlargeMemory optimized, r8g family
db.r8g.16xlarge prices and specsEvery size in the r8g family

Compare db.r8g.16xlarge with

db.m8g.16xlargedb.r8gd.16xlargedb.r8i.16xlargedb.r7g.16xlarge

Pay the committed rate, with commitment protection

The best committed rate on these two is 20–53% below on-demand. Connect your cloud accounts to unlock greater savings with commitment protection.

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AWS RDS PostgreSQL prices in USD. Monthly figures use 730 hours. Prices last updated 12 Nov 2026.