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SSD slower than expected?

Moineaufluo -  
epango Posted messages 37195 Registration date   Status Member Last intervention   -
Hello,

I had a quick fix for a RAM issue, gg.

And I got two SSDs, one M.2 8860 which I put in an external case.
And a classic 2.5-inch one that I put in the tower. So I'm very happy! It's fast!
But technically, I bought products that should have at least 550 MB/s write and 600 MB/s read speeds.

One Crucial MX500 M.2 SSD of 500 GB
and one Kingston 500 GB SSD, actually 480 GB!

I'm wondering why I'm getting transfer rates of about 225 MB/s from one to the other instead of the 550 MB/s that was expected? If you could enlighten me....
And how to know if the Crucial M.2 doesn't, by chance, have PCIe transfer rates?

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3 answers

  1.
    Judge_DT Posted messages 27651 Registration date   Status Moderator Last intervention   10 013
     
    Hello,

    But, technically I've bought products that go from a minimum of 550 write to 600 read.

    Actually, you're confusing minimum and maximum.

    It's rather the average maximum write rates.

    Sometimes more, sometimes less, but it's related to many difficult-to-control factors.

    --
    ~ To know how to listen is to possess, besides one's own, the minds of others... said Leonardo da Vinci.
    ~ “The art of writing is above all to make oneself understood” — Eugène Delacroix
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  2. epango Posted messages 37195 Registration date   Status Member Last intervention   Ambassadeur 4 270
     
    Your presentation lacks clarity. If it's an M.2 that you've put in the box, the apparent speed limitation can be explained by the port used to connect your box (USB, probably) which acts as a bottleneck, thus slowing down your SSD. On the other hand, your M.2 SSD doesn't use a PCI-E connection, but SATAIII.

    --
    Misnaming things adds to the world's misery (Albert Camus)
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  3. Moineaufluo Posted messages 9 Registration date   Status Member Last intervention  
     
    I was thinking of an SSD that goes through PCI. Or did I dream it?

    Wait, let me check the cable. Well no, it was for external to internal, but I switched to USB 3, I found that, but now it's between them.

    Judje_DT: I would like the max and min rates, but still 250MB.
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    1. epango Posted messages 37195 Registration date   Status Member Last intervention   4 270
       
      "I'm thinking of an SSD that connects via PCI. Or did I dream it?".

      M.2 SSDs via PCI-E, you didn't totally dream it. But that's not the case with yours. Among M.2 SSDs, some use SATA and others use PCI-E. Those that use PCI-E are labeled NVMe. They are much faster. M.2 SATA SSDs have speeds equivalent to those of 2.5" SATA SSDs.
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