# USB 3.0 speeds not quite 300MB/s

## RadiantDragoon87

Greetings, I hope to answer my question about my issue. I have a USB 3 motherboard but i am only seeing 100MB/s speeds in copying files. I am using EXFat as the File type. I am using an EVO 850 SSD 1 TB copying multiple 10 GB files from a LEXAR 1066 CF card on a USB 3.0 card reader but only seeing about 100 MB/s when i copy using CP command. when i use rsync -- progress i only see about 50 MB/s .

anything to increase copy speeds would be greatly helpful.

what information more would you need for me to assist.

lsb_release

gentoo 2.2

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## Yamakuzure

The full USB 3.0 speed must be supported by the device.I have a 1TB Corsair USB 3.0 Key, that can do over 250MB/s when copying files off it. Writing is a lot slower of course, but I have seen rates over 180MB/s.A 1TB USB 3.0 HD I use for backups barely reaches 200MB/s reading but can do almost 200MB/s when writing.The SanDisk Ultra 32GB Micro SDHC card I use in my raspberry PI 2 never gets over 120MB/s reading and 50MB/s when writing.

It all depends on the devices you use.

Might be worth reading: 31 USB 3.0 Thumb Drives, Tested And Reviewed

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## Anon-E-moose

For devices that can use it, UAS will provide a speed boost also.

Both the receiving end (motherboard) and the sending end (what the hd/usb stick/etc is plugged into) need to know about UAS.

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## NeddySeagoon

RadiantDragoon87,

Welcome to Gentoo.

EXFat will slow things down as its a userspace filesystem.

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## TigerJr

Bad test is copy from one bus to another, try to test coping from memory to device, this can show to you real device speed bandwidth or dd if=/dev/zero of=/mnt/device0

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## szatox

It seems you want to test interface speed. I'd use hdparm -T (AFAIR -T measures disk cache read speed).

You can also test drive read spead with hdparm -t.

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