r5b.4xlarge by Amazon Web Services

r5b.4xlarge is a Memory optimized Gen5 4xlarge server offered by Amazon Web Services with 16 vCPUs, 128 GiB of memory and 0 GB of storage. The pricing starts at 0.16 USD per hour.
16 vCPU
128 GiB Memory
Spare SCore
13,989
(All-cores)
1,328
(Single-core)

Specifications

Server Metadata

Vendor ID
aws
Name
r5b.4xlarge
Description
Memory optimized Gen5 4xlarge
Family
r5b
Hw Virt
Status
active
Observed At
2026-10-29T17:19:31.536129

Availability

REGION / IDSPOTONDEMAND
Ohio (US) / us-east-2
0.502 USD/h 1.192 USD/h
Oregon (US) / us-west-2
0.517467 USD/h 1.192 USD/h
Northern Virgina (US) / us-east-1
0.564375 USD/h 1.192 USD/h
Stockholm (SE) / eu-north-1
0.1751 USD/h 1.2635 USD/h
Quebec (CA) / ca-central-1
0.7337 USD/h 1.304 USD/h
Dublin (IE) / eu-west-1
0.527467 USD/h 1.336 USD/h
Milan (IT) / eu-south-1
0.2825 USD/h 1.4 USD/h
London (GB) / eu-west-2
0.485333 USD/h 1.4 USD/h
Seoul (KR) / ap-northeast-2
0.434067 USD/h 1.424 USD/h
Frankfurt (DE) / eu-central-1
0.481067 USD/h 1.424 USD/h
Singapore (SG) / ap-southeast-1
0.597867 USD/h 1.424 USD/h
Tokyo (JP) / ap-northeast-1
0.471233 USD/h 1.448 USD/h
Sydney (AU) / ap-southeast-2
0.546367 USD/h 1.448 USD/h
Sao Paulo (BR) / sa-east-1
0.309767 USD/h 1.896 USD/h

Processor

vCPUs
16
Hypervisor
nitro
CPU Allocation
Dedicated
CPU Cores
8
CPU Speed
3.1 GHz
CPU Architecture
x86_64
CPU Manufacturer
Intel
CPU Family
Xeon
CPU Model
8259CL
CPU L1D Cache
32 KiB
CPU L1D Cache Total
256 KiB
CPU L1I Cache
32 KiB
CPU L1I Cache Total
256 KiB
CPU L2 Cache
1 MiB
CPU L2 Cache Total
8 MiB
CPU L3 Cache
36 MiB
CPU L3 Cache Total
36 MiB
CPU Flags
fpu, vme, de, pse, tsc, msr, pae, mce, cx8, apic, sep, mtrr, pge, mca, cmov, pat, pse36, clflush, mmx, fxsr, sse, sse2, ss, ht, syscall, nx, pdpe1gb, rdtscp, lm, constant_tsc, rep_good, nopl, xtopology, nonstop_tsc, cpuid, aperfmperf, tsc_known_freq, pni, pclmulqdq, ssse3, fma, cx16, pcid, sse4_1, sse4_2, x2apic, movbe, popcnt, tsc_deadline_timer, aes, xsave, avx, f16c, rdrand, hypervisor, lahf_lm, abm, 3dnowprefetch, pti, fsgsbase, tsc_adjust, bmi1, avx2, smep, bmi2, erms, invpcid, mpx, avx512f, avx512dq, rdseed, adx, smap, clflushopt, clwb, avx512cd, avx512bw, avx512vl, xsaveopt, xsavec, xgetbv1, xsaves, ida, arat, pku, ospke, avx512_vnni
Ecpus
10.5
Scalability
65.62

System Resources and Accelerators

MEMORY
Memory Amount
128 GiB
Memory Amount Actual
128 GiB
Memory Generation
DDR4
Memory Speed
2933 Mhz
ACCELERATORS
Accelerator Count
0
Accelerator Memory Min
0 MiB
Accelerator Memory Total
0 MiB
Accelerators
    STORAGE
    Storage Size
    0 GB
    Storages
      NETWORK
      Network Speed Baseline
      5 Gbps
      Network Speed Max
      10 Gbps
      Network Storage Speed Baseline
      10 Gbps
      Network Storage Speed Max
      10 Gbps
      Inbound Traffic
      0 GB/month
      Outbound Traffic
      0 GB/month
      IPv4
      0

      Server Description

      A memory-optimized x86_64 server featuring 128 GB of RAM, balanced multi-core performance, and dedicated resources for memory-intensive enterprise workloads.

      Memory OptimizedGeneral Purpose

      The Amazon Web Services r5b.4xlarge is a memory-optimized, fifth-generation instance utilizing the Nitro hypervisor. It features an Intel Xeon 8259CL x86_64 processor with 16 vCPUs (8 physical cores) running at 3.1 GHz, paired with 128.0 GB of DDR4 memory. The instance lacks local storage and dedicated GPUs, relying on a 5 Gbps baseline network. Performance benchmarks indicate a tradeoff: single-core CPU execution and single-threaded compression are weak, falling into the bottom 25%, whereas multi-core processing, memory bandwidth, and database operations perform in the average, middle-50% tier. Qualitatively, the r5b.4xlarge provides a high-density memory configuration relative to its compute resources, making it cost-effective for memory-bound workloads. It is highly suited for database deployments, caching layers, and multi-threaded enterprise applications that benefit from large memory capacities rather than peak single-core processing speeds.

      Economics

      Average Price per Region

      Prices per Zone

      Lowest Prices

      Performance

      Workload Profiles

      0.76Score
      Precomputed compound score for Cache Intensive workloads. A weighted average (geometric mean) of benchmark scores compared to their medians: score = ∏ (x_i / m_i)^(w_i / Σw). The score of 1.0 represents a synthetic baseline server with the median performance of each component benchmark; 0.5 means roughly half the performance; and 2.0 means twice the performance of that reference profile. Component weights: 50% Redis RPS (pipeline=1, SET), 20% Redis RPS (pipeline=16, SET), 10% PassMark Memory Mark (composite), 10% Memory bandwidth (read, 16 MB ~ L3), 10% PassMark single-thread CPU. Rationale for component selection: In-memory key-value store workload, mixing direct Redis performance metrics with memory speed and latency benchmarks, and single-core CPU performance profiles.
      Component Score Weight Impact
      Raw Reference Normalized Target Actual
      Redis RPS (pipeline=1, SET) 1,362,813 ops/sec 1,919,289 ops/sec 0.74 50.00% 50.00% -14.00%
      Redis RPS (pipeline=16, SET) 8,476,331 ops/sec 11,728,058 ops/sec 0.71 20.00% 20.00% -6.60%
      PassMark Memory Mark (composite) 2,187 2,416 0.92 10.00% 10.00% -0.83%
      Memory bandwidth (read, 16 MB ~ L3) 93,566 MB/sec 108,466 MB/sec 0.85 10.00% 10.00% -1.60%
      PassMark single-thread CPU 1,812 Mops/s 2,365 Mops/s 0.75 10.00% 10.00% -2.80%

      Memory Bandwidth

      Compression

      OpenSSL

      Geekbench Single-Core

      Score: 1,133

      Geekbench Multi-Core

      Score: 6,974

      Passmark CPU Scores

      BENCHMARKSCORE
      Mark
      		 14,306
      Compression
      		 201,443
      Encryption
      		 6,239
      Extended Instructions
      		 12,272
      Floating Point Maths
      		 24,301
      Integer Maths
      		 45,361
      Physics
      		 1,407
      Prime Numbers
      		 75
      Single Threaded
      		 1,812
      String Sorting
      		 23,430

      Passmark Memory Scores

      BENCHMARKSCORE
      Memory Mark
      		 2,187
      Database Operations
      		 5,120
      Memory Latency
      		 61
      Memory Read Cached
      		 22,120
      Memory Read Uncached
      		 8,459
      Memory Write
      		 7,839

      Stress-ng Raw Scores

      Stress-ng Relative Multicore Performance

      LLM Inference Speed for Prompt Processing

      LLM Inference Speed for Text Generation

      Static Web Server

      Redis

      Alternatives

      Servers of the Same Family

      INSTANCEvCPUsMEMORYAccelerators
      r5b.large 216 GiB0
      r5b.xlarge 432 GiB0
      r5b.2xlarge 864 GiB0
      r5b.8xlarge 32256 GiB0
      r5b.12xlarge 48384 GiB0
      r5b.16xlarge 64512 GiB0
      r5b.24xlarge 96768 GiB0

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      r5b.4xlarge FAQs