USB 2 vs. USB 3 speeds??

I am feeling like something may be out of whack with my internal USB 3.0 PCIe card. I believe I have the latest Renesas drivers for this card which is identified as a JMicro JMB36X controller.

I believe the PCIe port on my Dell XPS 435/900 is ver 2.

Any thoughts on these results from Crystal Disk Mark? These results were achieved by plugging the USB thumb drives directly into the USB 3.0 port on the PCIe card.

Patriot Rage XT USB 2.0
Seq. Read 32.65 MB/s
Seq. Write 26.35 MB/s

Patriot Supersonic Express USB 3.0
Seq. Read 81.73 MB/s
Seq. Write 25.59 MB/s

Read is about 2.5 x better than USB 2 but the Write is almost the same???

Just for kicks, here are the results from my USB 3.0 HD enclosure plugged into the same PCIe card. I have a 2TB, 7200 RPM, Sata2 drive in here. Forgot what brand.

Seq. Read 114.8 MB/s
Seq. Write 93.02 MB/s

Any comments on these numbers? I have been thinking of looking for a new PCIe card.

Thx DD
2 answers Last reply
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  1. Maybe it's the usb stick that your using that's the issue and not the pci-e card , the pci-e card seems to be working and that would not have aything to do with the write speeds simce it did record the read speeds . My guess is that the usb stick is at fault and should be tested on another machine that has usb 3.0 so you can verify the results.
  2. Based on some other articles it seems the bottleneck is the PCIe 1x port, even if it is rev2. The port I have the card in is PCIe x8 and have found a USB3.0 card which is PCIe x4. It will be interesting to see if there is a substantial improvement with the 4x card.
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