Usb ports speed is 2.0 not 3.0 on macbook retina 15 el capitain

I have a problem with USB speed performance on my Macbook.

I have a Macbook Pro (Retina, 15-inch, Mid 2015), Processor 2.5 GHz Intel Core i7
Memory 16GB
It runs Os X El Capitan
I have lately encounter some issues with my USB external drives. Though I am using USB 3.0 drives their transfer speed is consistently USB 2.0 (max 430 Mbps, not even 480).


The external HD are different brands, one is LaCie P9220 Media 2 TB and 1 is BUFFALO HD-PNTU3

I have to format the LaCie recently, and i am doing some backup transfer files. But is all very slow.

I tried transferring single files

1.04 GB takes 13.40seconds from external to SSD internal drive. About 15 sec to another external HD USB 3.0
Large folders : Transferred 39.68 GB from the Lacie to the Buffalo in 12m13s (about 429mbs)

The USB Device Tree under system report shows the two drives as USB 3.0.

The cables are working fine (the usb 3 cable and no external extension)
I tried with one HD connected same results.
I reset PRAM and SMC, same results.

Any suggestions to get the drives perform as per their specifications?

G'day band welcome to nthe forums.

I found when having this problem there are a lot of bogus USB3 cables out there flooding the world from China.

They look like USB3, blue colour and branded etc, but work at USB2 speeds.


http://community.ebay.com/t5/Shippi...FAKE-USB-3-0-CABLES-BEING-SOLD/qaq-p/22018512

Hi thanks for the reply. I understand the issues with cables, but i am only using the ones that came with the drives (both bought from from Amazon (not external vendors). The two drives used to be faster.

The two drives used to be faster.

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Can you tell us what that means? How do you know? What changed at the time the drives became slower? How much room is available on each drive? How are the drives formatted? Are you using any USB hubs? What other USB devices are also plugged in at the same time as these drives?

MacInWin said:

Can you tell us what that means? How do you know? What changed at the time the drives became slower? How much room is available on each drive? How are the drives formatted? Are you using any USB hubs? What other USB devices are also plugged in at the same time as these drives?

Click to expand...

The transfer rate was much faster before, that's it. Last week one of the drives (the Lacie) failed and Disk Utility informed be the drives could not be repaired. It could be open and I could copy files from it though. So i did some backup, I copied some files from Lacie to the Buffalo. The first time I attached the Lacie on the computer port and the buffalo through a usb 3.0 hub (together with another USB 3.0 hd). However when i noticed the very slow transfer rate I realised that the usb extension cable i was using for the hub was usb 2.0 and that might effect the USB port speed. I unplugged everything. I reset PRAM and SMC (twice) and attached the two USB 3.0 drives one for each of the two USB ports of of my Macbook Pro. So there were only two drives attached on the computer at the same time, one for each available port. I formatted the Lacie (so it was 2TB empty) while the Buffalo was 2/3 full. (with 600gb full out of 1tb) The rate transfer however was never more than 430Mbps.

Any insight?

thanks.

If Disk Utility said the drives could not be repaired, that is the source of the slowness. The drives are failing. You'll need to get new ones, copy what you can rescue and retire the drives from service.

In general, once drives have decayed to where DU reports them to be un-repairable, they are close to dead. You can TRY to reformat them, but that is a temporary fix.

Hi thanks again for the reply. The issue with disk utility was only with one disk (all the others are fine).

The error was: 'Error: Disk Utility can't repair this disk.Back up as many of your files as possible, reformat the disk, and restore your backed-up files"

This error however does not always means the disk is physically damaged. The disk utility fail is often due to not reading the logical volume, the disk itself has no bad sector (some that happens when the disk is disconnected improperly by accident). So the disk Lacie should be fine. In any case the slow transfer rate affects even the others. I tried only with the Buffalo (i have in fact several of them) and with transfer data from the buffalo to my computer main hard drive (with only the buffalo connected and after resetting PRAM and SMC). Transfer rate remains the same.

Download SMARTReporter and be guided by what it says. There is a trial version available here:-


https://www.corecode.io/smartreporter/

This error however does not always means the disk is physically damaged. The disk utility fail is often due to not reading the logical volume, the disk itself has no bad sector (some that happens when the disk is disconnected improperly by accident). So the disk Lacie should be fine. In any case the slow transfer rate affects even the others. I tried only with the Buffalo (i have in fact several of them) and with transfer data from the buffalo to my computer main hard drive (with only the buffalo connected and after resetting PRAM and SMC). Transfer rate remains the same.

Click to expand...

So, did you actually disconnect it improperly and forgot to tell us? That is a key thing to omit.

If not, one of the first symptoms of failing drives is a slowdown in performance. The internal firmware on the drive itself does error checking for reads and writes, and if it starts to have to repeat the I/O operation multiple times before it succeeds, the drive slows down. But the OS (and thus, DU) doesn't see the errors because the drive eventually reports success at the operation. So DU thinks the drive is OK because eventually things work, but the overall performance is poor. And eventually even the firmware cannot get past the errors and the drive fails totally.

Maybe the slowdowns for the OP are caused by the internal SSD in his rMBP. Folks think that because they now have a SSD rather than a spinning hard drive in their machine that it will never fail or slow down. Wrong. SSDs do fail and they do slow down and sometimes quite suddenly.

Might be, Charlie, but more typically SSD just die, catastrophically. I've not heard of one slowing down first. But hey, electronics do strange things!