[SOLVED] New Crucial MX500 1TB speed anomaly

[Pimpom]

I received a new MX500 1TB SSD yesterday and partitioned it in GPT style but have not yet populated it. MiniTool Partition Wizard reports that it's properly aligned.

I've just finished testing it with CDM, first with my desktop both as an internal drive and as an external USB drive. In both cases, it showed ~240MB/s read and ~400 MB/s write speeds. Then I remembered that SATA is set to IDE mode. That must be it, I thought.

But then the boot drive, a BX500 120GB, runs at ~480 MB/s read and ~400 MB/s write. I thought the new drive might be defective, so I ran the test again with the new drive connected via USB to a laptop with SATA in AHCI mode. It returned a more reasonable ~450 MB/s read and write.

So why does the new MX500 show such a dismal read speed in IDE mode while the existing BX500 drive runs at roughly normal speed on the same computer? Could it be because they use different controllers and firmware?

The desktop has a Phenom II x4 970 on an MSI 970A-G43 with 8GB DDR3. The laptop is an Acer Aspire A315-56-323J using an i3-1005G1 and 8GB DDR4. Both Windows 10.

 

[Maxxify]

You don't want to be running SSDs as IDE regardless.

 

[Pimpom]

Thanks for the reply but it doesn't really address the question. The aim here is to understand the reason behind the huge discrepancy in read speed when the other SSD doesn't show such behaviour. The new SSD is for another laptop (not the one I tested it with) and it will be run in AHCI mode.

 

[Maxxify]

Their controllers are extremely similar, just one has DRAM and one does not. There are firmware differences primarily depending on the flash inside (which varies). You stated you tried the MX500 as an external drive and it still had the issue which has nothing to do with IDE as it's going over USB and the SATA/drive is on the other side of the enclosure's bridge chip. These chips are UASP, the S standing for SCSI.