Looks like no one’s replied in a while. To start the conversation again, simply ask a new question.

mac USB ports

I have a late 2013 iMac which has been updated with all the latest software. I am sure that the USB ports which are advertised as USB 3 are not USB 3 at all. When I attach an external hard drive via USB 3 to back up my laptop running windows 8.1 the speed is blisteringly fast. When I do the same with my mac it is slower than a snail on valium. Is this normal? Am I doing something wrong? Please help. Thank you

iMac (27-inch, Late 2013), OS X Mavericks (10.9.4)

Posted on Jul 18, 2014 2:11 PM

Reply
14 replies

Jul 18, 2014 2:55 PM in response to bradley andrew

The fastest speed you can between the two end-point is determined by the slowest link in the chain.


1. Are their disk drive differences between the W8.1 machine and iMac. For example, the faster device may have an SSD, while the slower has an HDD.

2. How much data is being copied between the two end-points in both cases?

3. Is the Data rate (Gb/second) the same?

4. Are you copying a large single file on W8.1 vs a number of smaller files in the slower iMac case?

Jul 18, 2014 2:57 PM in response to bradley andrew

You have confirmed you have USB 3 ports (which we all knew anyway as they been on iMacs since the 2012 models), however how is your EHD formatted? You mentioned it is fast on you Windows box, so my guess is the drive is formatted for MS Windows and not OS X. Also you may want to consider a higher quality EHD such as a OWC Mercury Elite Pro. WD's have a long history of being problomatic with OS X, WD uses cheap enclosures and electronics which seem to work fine with PCs however frequently do not with OS X.

Jul 18, 2014 3:07 PM in response to rkaufmann87

I have two EHHDs which have been formatted differently. one passport for mac (extended OS) and one for my laptop using windows formatting. Yes they are both WD one sold as EHD for mac and one for windows 8.1. If you are saying that these do not work properly with OSX then I should return the passport for mac to the retailer as being not fit for purpose. Would the mercury elite pro definitely be better? I am pretty clueless when it comes to this kind of stuff but it is a steep learning curve


Thanks for your help

Jul 18, 2014 3:12 PM in response to bradley andrew

Mercury Elite Pro series would be a major upgrade over WD that is for sure, when you see one you will see why they cost more, the build quality is evident by just looking at them. If you decide to get one then get a 3.5" drive as they are 7200RPM drives, you can get Mercuy Elite Pro's in a mini size however they are 5400RPM drives.


Here is a link for you to begin looking:


http://eshop.macsales.com/shop/firewire/1394/USB/EliteAL/eSATA_FW800_FW400_USB

Jul 20, 2014 4:04 AM in response to bradley andrew

FWIW, plugged into the back of my new 27" iMac are:

-LG Portable Super Multi Blue Rewriter (USB2.0/480 megabit)

-Back-UPS ES 750 monitor connection (USB1.1/1.5 Megabit)


I connect a couple different USB3.0 HDD drives at various times

and get the following:

-Seagate Backup+ portable with USB3.0 adapter (Connection USB3.0/5Gbit./sec)

As a verification, ran BlackMagic Disk speed test and got ~75-80 Megabyte/sec

which translates to 600-640 megabit (USB2.0 is 480 Max.).

-Startech USB3.0 enclosure (Connection USB3.0/5Gbit./sec). I get a 70-75 Megabyte

transfer speed.

Both of these tests are pretty much inline with what one would expect from portable

HDDs and is typically close to the max for these drives.


So for one, at least on my iMac, the highest speed is NOT dictated by the slowest device.

Jul 20, 2014 6:12 AM in response to bradley andrew

bradley andrew wrote:

If you are saying that these do not work properly with OSX then I should return the passport for mac to the retailer as being not fit for purpose.

Frankly, I doubt the problem is that the WD Passport for Mac is not suitable for use with your iMac. Contrary to what some are saying, the build quality is fine & many, many iMac users have no problems at all with them.


However, the same cannot be said for the WD software that comes with them. If you have installed any of that on your iMac, that may be the cause of the slowdown. You don't need any of that software unless you really need some proprietary feature only it provides, like S.M.A.R.T. support (OS X only supports that for internal drives on iMacs) or WD's method of disk encryption. The first is of dubious value & the second would be useful (maybe) only if you want to encrypt the contents of the drive & be able to access it from either Windows or OS X.


If you will tell us the exact model name of your Passport & (if you know) what if any WD software you have installed, we can probably give you more specific advice.

Jul 20, 2014 6:25 AM in response to woodmeister50

woodmeister50 wrote:


Both of these tests are pretty much inline with what one would expect from portable

HDDs and is typically close to the max for these drives.


So for one, at least on my iMac, the highest speed is NOT dictated by the slowest device.

We seem to be in violent agreement with each other that the slowest link in the chain is the limiting factor. 😉

mac USB ports

Welcome to Apple Support Community
A forum where Apple customers help each other with their products. Get started with your Apple ID.