db.r8a.4xlargevsdb.r8i.4xlarge

db.r8i.4xlarge is 13% cheaper than db.r8a.4xlarge on demand in US East (N. Virginia), saving $230.10 a month. Per vCPU, db.r8i.4xlarge costs 57% less.

At a glance	db.r8a.4xlarge	db.r8i.4xlarge
On-demand	$2.415/hr	$2.10/hr13% less
Lowest rate	$1.932/hr1-yr savings plan, hourly commitment	$1.68/hr13% less1-yr savings plan, hourly commitment
Size	8 vCPUs, 128 GiB	16 vCPUs, 128 GiB

Prices in US East (N. Virginia)

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

Option	db.r8a.4xlarge	db.r8i.4xlarge	db.r8i.4xlarge vs db.r8a.4xlarge
On-demandPay by the hour	$2.415	$2.10	▼ 13%
1-yr reservedNo upfront	—	33% off$1.407	—
3-yr reservedNo upfront	—	53% off$0.987	—
1-yr savings planHourly commitment	20% off$1.932	20% off$1.68	▼ 13%

Key differences

The biggest lead each one has.

Where db.r8a.4xlarge leads

Physical cores16 vs 8

2× higher

Where db.r8i.4xlarge leads

On-demand price$2.10 vs $2.415 per hour

13% cheaper

vCPUs16 vs 8

2× higher

Specs

14 of 24 specs differ. Those are in bold.

Compute7 of 8 differ	db.r8a.4xlarge	db.r8i.4xlarge
vCPUs	8	16
Physical cores	16	8
Threads per core	1	2
Architecture	x86_64	–
Processor	5th Generation AMD EPYC	–
CPU maker	AMD	Intel
Sustained clock	4.5 GHz	3.9 GHz
Burstable	No	No

MemoryAll 1 match	db.r8a.4xlarge	db.r8i.4xlarge
Memory (GiB)	128	128

Networking1 of 3 differ	db.r8a.4xlarge	db.r8i.4xlarge
Network	Up to 15000 Mbps	–
Network baseline	7.5 Gbps	7.5 Gbps
Network peak	15 Gbps	15 Gbps

Storage1 of 7 differ	db.r8a.4xlarge	db.r8i.4xlarge
Storage	EBS Only	–
EBS baseline bandwidth	5,000 Mbps	5,000 Mbps
EBS max bandwidth	10,000 Mbps	10,000 Mbps
EBS baseline throughput	625 MB/s	625 MB/s
EBS max throughput	1,250 MB/s	1,250 MB/s
EBS baseline IOPS	20,000	20,000
EBS max IOPS	40,000	40,000

Instance details4 of 4 differ	db.r8a.4xlarge	db.r8i.4xlarge
Family	r8a	r8i
Category	Memory optimized	–
Current generation	Yes	–
Normalization factor	–	32

Other1 of 1 differ	db.r8a.4xlarge	db.r8i.4xlarge
Hardware Basis	r8a.4xlarge	r8i.4xlarge

On-demand prices by region

Cheapest for db.r8a.4xlarge first. PostgreSQL, USD per hour.

Region	db.r8a.4xlarge	db.r8i.4xlarge	Difference
US East (N. Virginia)Used in summaryus-east-1	$2.415	$2.10	▼ 13%
US East (Ohio)us-east-2	$2.415	$2.10	▼ 13%
US West (Oregon)us-west-2	$2.415	$2.10	▼ 13%
Canada (Central)ca-central-1	$2.608	$2.27	▼ 13%
EU (Ireland)eu-west-1	$2.705	$2.35	▼ 13%
Europe (Spain)eu-south-2	$2.705	$2.35	▼ 13%
Asia Pacific (Tokyo)ap-northeast-1	$2.898	$2.52	▼ 13%
EU (Frankfurt)eu-central-1	$2.946	$2.56	▼ 13%

Keep exploring

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

db.r8a.4xlargeMemory optimized, r8a family

db.r8a.4xlarge prices and specs Every size in the r8a family

Compare db.r8a.4xlarge with

db.r8g.4xlarge db.m8a.4xlarge

db.r8i.4xlarger8i family

db.r8i.4xlarge prices and specs Every size in the r8i family

Compare db.r8i.4xlarge with

db.m8i.4xlarge db.r8g.4xlarge db.r7i.4xlarge db.r7i.4xlarge.tpc2.mem2x db.r7i.4xlarge.tpc2.mem3x db.r7i.4xlarge.tpc2.mem4x

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.