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Nvme

PM991a Samsung 256GB

▲ 500 ▼

Release date ≈ Q1 2021.

Average Bench: 118% (192nd of 1072)

Based on 1,499 user benchmarks.  Model: NVMe PM991a NVMe Samsung 256GB
Poor: 57%Average: 118% Great: 205%

Popular builds with this SSD

Outstanding average bench

The Nvme PM991a Samsung 256GB averaged 18.5% higher than the peak scores attained by the group leaders. This is an excellent result which ranks the Nvme PM991a Samsung 256GB near the top of the comparison list.

Strengths

Avg. 4K-64Thread Mixed IO Speed 353MB/s
Avg. 4K-64Thread Read Speed 545MB/s

Terrible consistency

The range of scores (95th - 5th percentile) for the Nvme PM991a Samsung 256GB is 148%. This is a particularly wide range which indicates that the Nvme PM991a Samsung 256GB performs inconsistently under varying real world conditions.

Weaknesses

Avg. Sustained Write Speed 256MB/s
Avg. Sequential Write Speed 488MB/s
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Average Bench

(Based on 1,499 samples)
Rank 192118%
Min Avg Max
495 Read 979 1,508
79.2 Write 488 1,153
149 Mixed 516 1,190
80.3 SusWrite 256 535
124% 560 MB/s
Min Avg Max
14.5 4K Read 33.7 51.6
31.6 4K Write 87 152
14.8 4K Mixed 39.6 71.9
148% 53.4 MB/s
Min Avg Max
199 DQ Read 545 883
78.2 DQ Write 287 1,020
123 DQ Mixed 353 815
279% 395 MB/s
User Benchmarks BenchSequentialRandom 4kDeep queue 4k
The fastest SSD (mainstream) averages a speed of 100%
152GB free (System drive)
Firmware: 26304039 Max speed: PCIe 16,000 MB/s
SusWrite @10s intervals: 820 839 669 137 108 155 MB/s
155% Outstanding
Read 1,113
Write 998
Mixed 843
SusWrite 455
191% 852 MB/s
4K Read 23.6
4K Write 122
4K Mixed 56
172% 67.3 MB/s
DQ Read 882
DQ Write 368
DQ Mixed 658
479% 636 MB/s
193GB free (System drive)
Firmware: 26302039 Max speed: PCIe 16,000 MB/s
SusWrite @10s intervals: 822 723 678 172 128 120 MB/s
142% Outstanding
Read 1,037
Write 1,002
Mixed 876
SusWrite 441
188% 839 MB/s
4K Read 39.6
4K Write 78
4K Mixed 51
167% 56.2 MB/s
DQ Read 502
DQ Write 449
DQ Mixed 432
336% 461 MB/s
20GB free (System drive)
Firmware: 26304039 Max speed: PCIe 16,000 MB/s
SusWrite @10s intervals: 99 92 89 90 89 86 MB/s
111% Outstanding
Read 1,099
Write 97.5
Mixed 176
SusWrite 90.9
78% 366 MB/s
4K Read 39.6
4K Write 95.8
4K Mixed 40
162% 58.5 MB/s
DQ Read 480
DQ Write 91.9
DQ Mixed 154
147% 242 MB/s
86GB free (System drive)
Firmware: 26304039 Max speed: PCIe 16,000 MB/s
SusWrite @10s intervals: 109 105 98 104 102 98 MB/s
103% Outstanding
Read 1,075
Write 110
Mixed 224
SusWrite 103
81% 378 MB/s
4K Read 33.5
4K Write 68.9
4K Mixed 36
133% 46.1 MB/s
DQ Read 486
DQ Write 109
DQ Mixed 169
157% 255 MB/s
8GB free (System drive)
Firmware: 26304039 Max speed: PCIe 16,000 MB/s
SusWrite @10s intervals: 92 79 77 75 71 68 MB/s
99.4% Outstanding
Read 1028
Write 90.6
Mixed 169
SusWrite 77.1
73% 341 MB/s
4K Read 31.7
4K Write 83.8
4K Mixed 33.3
135% 49.6 MB/s
DQ Read 488
DQ Write 73.6
DQ Mixed 166
151% 243 MB/s
8GB free (System drive)
Firmware: 26304039 Max speed: PCIe 16,000 MB/s
SusWrite @10s intervals: 83 75 69 67 63 57 MB/s
94.7% Outstanding
Read 1,009
Write 87.6
Mixed 134
SusWrite 68.9
69% 325 MB/s
4K Read 30.9
4K Write 74.6
4K Mixed 29.7
124% 45.1 MB/s
DQ Read 484
DQ Write 77.7
DQ Mixed 146
141% 236 MB/s
161GB free (System drive)
Firmware: 26304039 Max speed: PCIe 16,000 MB/s
SusWrite @10s intervals: 140 119 115 102 116 78 MB/s
80.3% Excellent
Read 785
Write 233
Mixed 238
SusWrite 112
74% 342 MB/s
4K Read 28.5
4K Write 56.6
4K Mixed 27.6
108% 37.6 MB/s
DQ Read 290
DQ Write 115
DQ Mixed 186
142% 197 MB/s
126GB free (System drive)
Firmware: 26304039 Max speed: PCIe 16,000 MB/s
SusWrite @10s intervals: 114 128 125 111 121 101 MB/s
80.1% Excellent
Read 807
Write 131
Mixed 204
SusWrite 117
68% 315 MB/s
4K Read 17.1
4K Write 61.1
4K Mixed 22.9
88% 33.7 MB/s
DQ Read 466
DQ Write 160
DQ Mixed 227
190% 284 MB/s
1,499 MORE »

 Market Share (See Leaders)

The number of benchmark samples for this model as a percentage of all 75,729,484 SSDs tested

Custom PC Builder (Start a new build) Build your perfect PC: compare component prices, popularity, speed and value for money

CHOOSE A COMPONENT:

CPU GPU SSD HDD RAM MBD
Typical PM991a Samsung 256GB Builds (Compare 3,649 builds) See popular component choices, score breakdowns and rankings
Gaming
Gaming 13%
Tree trunk
Desktop
Desktop 74%
Battleship
Workstation
Workstation 11%
Tree trunk

System: Dell Inspiron 15 3511

CPU
Core i5-1135G7IntelBench 69%, 36,962 samples1,740x
Core i3-1115G4IntelBench 51%, 18,815 samples873x
Core i7-1165G7IntelBench 66%, 51,565 samples543x
GPU
Iris XeIntelBench 14%, 144,774 samples2,146x
UHD GraphicsIntelBench 9%, 39,662 samples908x
UHD G1IntelBench 5%, 68,603 samples458x
SSD
PM991a Samsung 256GBNvmeBench 118%, 1,499 samples1x
RAM
HMAA1GS6CJR6N-XN 1x8GBUnknownBench 32%, 13,137 samples1,025x
M471A1G44BB0-CWE 1x8GBSamsungBench 34%, 7,899 samples350x
HMAA1GS6CJR6N-XN 2x8GBUnknownBench 65%, 26,875 samples285x
EDIT WITH CUSTOM PC BUILDER

Popular PM991a Samsung 256GB systems:

How Fast Is Your SSD? (Bench your build) Size up your PC in less than a minute

Welcome to our PC speed test tool. UserBenchmark will test your PC and compare the results to other users with the same components. You can quickly size up your PC, identify hardware problems and explore the best value for money upgrades.

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How it works

  • - Download and run UserBenchmark
  • - CPU tests include: integer, floating and string
  • - GPU tests include: six 3D game simulations
  • - Drive tests include: read, write, sustained write and mixed IO
  • - RAM tests include: single/multi core bandwidth and latency
  • - SkillBench (space shooter) tests user input accuracy
  • - Reports are generated and presented on userbenchmark.com
  • - Identify the strongest components in your PC
  • - See speed test results from other users
  • - Compare your components to the current market leaders
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Solid State Drive Rankings (Price vs Performance) April 2024 SSD Rankings

Welcome to our 2.5" and M.2 SSD comparison. We calculate effective speed for both SATA and NVMe drives based on real world performance then adjust by current prices per GB to yield a value for money rating. Our calculated values are checked against thousands of individual user ratings. The customizable table below combines these factors to bring you the definitive list of top SSDs. [SSDrivePro]

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Group Test Results

  • Best user rated - User sentiment trumps benchmarks for this comparison.
  • Best value for money - Value for money is based on real world performance.
  • Fastest real world speed - Real World Speed measures performance for typical consumers.

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Speed Comparisons

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See how consistently different SSDs perform with varying real world conditions. The charts also illustrate overall performance, popularity and rank.

 Frequently Asked Questions

Storage Devices FAQ
What is sustained sequential write speed?
What’s the difference between SLC, MLC and TLC?
What is 3D XPoint and how fast is it?
What’s the difference between SATA, PCIe and NVMe?
What’s the difference between NAND and V-NAND?
What is sequential write speed?
What is sequential read speed?
What is incompressible data?
What is queue depth?
Solid State Drives
What is the SSD value for money rating?
What is 4K 64 thread write speed?
Can CPU power saving states (C1,C2,C3) impact SSD speed?
What is the effective SSD speed index?
How is the AS SSD write score calculated?
How is the AS SSD read score calculated?
How is the AS SSD total score calculated?
ALL FAQs »

 Best User Rated
The Best.
CPUGPUSSD
Intel Core i5-13600K $273Nvidia RTX 4060 $295Crucial MX500 250GB $40
Intel Core i5-12400F $133Nvidia RTX 4060-Ti $385Samsung 850 Evo 120GB $80
Intel Core i5-12600K $179Nvidia RTX 4070 $539Samsung 860 Evo 250GB $52
HDDRAMUSB
Seagate Barracuda 1TB (2016) $39Corsair Vengeance LPX DDR4 3200 C16 2x8GB $45SanDisk Extreme 64GB $72
WD Blue 1TB (2012) $37Corsair Vengeance LPX DDR4 3000 C15 2x8GB $43SanDisk Extreme 32GB $28
Seagate Barracuda 2TB (2016) $51G.SKILL Trident Z DDR4 3200 C14 4x16GB $351SanDisk Ultra Fit 32GB $16
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