external drives copying slow

You seem to have an older Mac and they only have USB 2 ports. So even if you buy USB 3 drives the transfer rate will only be at USB 2 speeds. Ethernet can even be slower. Also the transfer rate is governed by several different factors. Speed of the connection and speed of the drive.

check your activity monitor when this happens, what processes are running? what ram is being used? what kind of disk activity is there?

Check console during the slowness, any messages seem to appear to let you know what is going on?

Time to minimize. Unhook all USB devices from the computer but the mouse and keyboard. Also disconnect the display. Power down the computer and the hard drives. After restarting the computer connect one USB device at a time to the computer and copy a file to it. Repeat until you've connected all the USB devices (or run out of ports). At some point you may add a device that slows stuff down. That's the suspect device. If you get everything connected without a slowdown, add the display to the mix.

It could be that the power down solves the problem or that you'll find a device that is causing a conflict.

unfortunately not much to go on there

however it appears numerous people have issues with the WD externals.

Which one is timemachine and which one is your external that you use for other stuff? The wired or wireless?

I have read that if you have a slow transfer, open up activity monitor and quit finder through activity monitor. People say that for some reason boosts transfer speeds. So open activity monitor, click on finder in activity monitor, then click the grey x above process name to close the finder.

Can you make sure your activity monitor is displaying all processes and post again?

I have a similar problem. I have a late 2013 MacBook Pro 13 inch with 8GB RAM and 256GB SSD. OS X Mavericks version 10.9.4 installed.

I am writing an ISO file to a USB flash drive using the dd command in a terminal window. When doing this against a Supersonic Magnum 12GB USB 3 flash drive I achieve around 800 KB/sec. System information confirms that the Magnum is connected at 5Gbit/sec. When monitoring the throughput with iostat I see this:

4.00 559 2.18

4.00 556 2.17

4.00 556 2.17

4.00 564 2.20

4.00 560 2.19

4.00 557 2.18

disk2

KB/t tps MB/s

4.00 568 2.22

4.00 385 1.51

4.00 311 1.22

4.00 312 1.22

4.00 291 1.14

4.00 306 1.19

4.00 273 1.07

4.00 255 1.00

4.00 246 0.96

4.00 238 0.93

4.00 230 0.90

4.00 170 0.66

4.00 209 0.82

4.00 165 0.64

4.00 147 0.57

4.00 122 0.48

4.00 97 0.38

4.00 103 0.40

4.00 63 0.25

4.00 65 0.25

disk2

KB/t tps MB/s

4.00 50 0.20

4.00 39 0.15

4.00 31 0.12

When doing the same to a SanDisk 16GB USB 2 flash drive I get around 2.4 MB/sec - about 3 times faster than the USB 3 Magnum drive...

I am in the process of setting up a Windows 8.1 Boot Camp partition on the internal SSD. When finished I will test the same under Windows to see if it's better or worse.

Just a quick update to my post above after testing the same Magnum flash drive under Boot Camp with Windows 8.1.

I installed Cygwin and used the dd command to repeat the test and got this:

$ dd if=Windows-8.1.iso of=/dev/sdc bs=1M

3200+1 records in

3200+1 records out

3355901952 bytes (3.4 GB) copied, 21.5151 s, 156 MB/s

Pretty good compared to the speed I got under Mavericks. 156 MB/sec compared to 800 KB/sec is 195 times faster.

This confirms that the problem lies in OS X - not the hardware.

From now on I will do all further USB flash writing from Windows.