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[SOLVED] Impossible ssd speeds?

roeiboot4

Prominent
Jan 1, 2018
6
0
510
Hi everyone,

When looking around for an nvme ssd upgrade, I first decided to benchmark my current SATA 850 EVO.
CDM gives:
Code:
------------------------------------------------------------------------------
CrystalDiskMark 7.0.0 x64 (C) 2007-2019 hiyohiyo
                                  Crystal Dew World: [URL]https://crystalmark.info/[/URL]
------------------------------------------------------------------------------
[LIST]
[*]MB/s = 1,000,000 bytes/s [SATA/600 = 600,000,000 bytes/s]
[*]KB = 1000 bytes, KiB = 1024 bytes
[/LIST]
[Read]
Sequential 1MiB (Q=  8, T= 1):  5661.387 MB/s [   5399.1 IOPS] <  1295.56 us>
Sequential 1MiB (Q=  1, T= 1):  8243.114 MB/s [   7861.2 IOPS] <   126.85 us>
    Random 4KiB (Q= 32, T=16):  2460.413 MB/s [ 600686.8 IOPS] <   823.81 us>
    Random 4KiB (Q=  1, T= 1):   405.425 MB/s [  98980.7 IOPS] <    10.00 us>

[Write]
Sequential 1MiB (Q=  8, T= 1):  5683.718 MB/s [   5420.4 IOPS] <  1288.88 us>
Sequential 1MiB (Q=  1, T= 1):  5677.030 MB/s [   5414.0 IOPS] <   184.17 us>
    Random 4KiB (Q= 32, T=16):  1765.282 MB/s [ 430977.1 IOPS] <  1149.52 us>
    Random 4KiB (Q=  1, T= 1):   275.664 MB/s [  67300.8 IOPS] <    14.70 us>

Profile: Default
   Test: 1 GiB (x5) [Interval: 5 sec] <DefaultAffinity=DISABLED>
   Date: 2019/12/20 23:53:36
     OS: Windows 10  [10.0 Build 18363] (x64)
I am read/writing sequentially at over 5.5 GB/s, where as sata III ssds are advertised at ~500 MB/s. What is going on here? I cross-checked with the Samsung magician software, and this gave 4.7 GB/s. With AS SSD benchmark:
Code:
AS SSD Benchmark 2.0.6821.41776
------------------------------
Name: Samsung SSD 850 EVO 250GB
Firmware: EMT02B6Q
Controller: storahci
Offset: 579584 K - OK
Size: 232.88 GB
Date: 12/21/2019 12:07:50 AM
------------------------------
Sequential:
------------------------------
Read: 4494.72 MB/s
Write: 2010.67 MB/s
------------------------------
4K:
------------------------------
Read: 113.95 MB/s
Write: 184.42 MB/s
------------------------------
4K-64Threads:
------------------------------
Read: 9834.10 MB/s
Write: 9661.70 MB/s
------------------------------
Access Times:
------------------------------
Read: 0.071 ms
Write: 0.027 ms
------------------------------
Score:
------------------------------
Read: 10398
Write: 10047
Total: 25576
------------------------------
Three independent bench-marking tools give me about a factor 10 better performance than expected (again: ~500 MB/s)
Can somebody explain this? Am I misinterpreting these results? Something else?

If these results are correct, why even bother upgrading to nvme ssds who read at about 1.5 GB/s? I am stumped here...
 
Yes, I do. After turning it off, I recover the expected speeds: 530MB/s read, 490 write.
So I was actually benchmarking my DRAM, not my SSD

thanks for clearing this up