Imac late 2013, Maverick, w/ fusion drive, possible usb problems.

I recently purchased an iMac, late 2013 with 3tb fusion drive. In searching forums regarding a usb connection issue I may have, I notice many threads relating to a consistent issue with usb on this model.

This a pasted quote from Peter McLaren as posted in the Apple Support Community:

"For those still wrestling with USB bus freezes with iMac Late 2013 with Fusion drive and Mavericks, and who don't want to have to wait till OSX 10.9.2, I have found the utlity posted at this link way back on October 25th solves the problem:

http://www.enttec.com/support-center/kb/article/108-OS_X_Mavericks_(10.9)_-_IMPO RTANT

Not sure why this link has not been posted on this thread before!

As you will note from the associated page the author claims that Apple wrote their own USB driver in Mavericks and it has issues. The utility disables it, and reverts to a standard driver.

I have been running for 48 hours with this driver fix installed with zero issues. Previously with a USB hub connected to my iMac I would get an hour or so at best before a USB freeze.

As other have reported the issue is the USB bus. The CPU itself does not crash; the iMac is still accessible via screenshare or fileshare while the bus is frozen, but it does take a restart to clear the USB bus freeze.

Hope this helps relieve some frustration while we all wait for OSX 10.9.2."

This "solution" reverts the usb3 port back to a usb2 until the fix comes.  I have not done this nor will I as I don't want to mess with something that may not be an issue for me.  There are many threads regarding usb and connection issues but the one consistent one relates to only late 2013, iMac, Maverick's with fusion drives.

It is not my attempt to induce concerns, but there are just too many threads regarding this model with this issue.  I have not found any threads relating to this observation on dpreview so thought it may be helpful to bring forward.  No fear mongering intended, I just think that we are a curious bunch and should be aware.

Are you having this issue or another? I'm not certain by the post. Is your fusion drive on the USB bus or is that not relevant to the problem?

I have a MBA with USB 3 and it hasn't had any problem with USB 3. I don't have a fusion drive though, only a SSD.

I had a small problem with a Spyder 3 and the usb connection. As a result, I searched for similar problems and notice a trend regarding only the iMac late 2013 model that had a fusion drive and was running Maverick. There have been many returns of this model with the exchanged units having exactly the same problem.

You can read about it here:

Massive problem with audio interface: Apple Support Communities

and here:

Forum - Main Forums : Mac Music - Sound On Sound

Audio problems with new iMac Fusion Drive - MacRumors Forums

Potential audio problem with new iMacs - Page 3 - Gearslutz.com

Some have reverted to Mountain Lion, problem resolved.

Reverted to usb 2 drivers, problem solved.  A few have booted from another source with no problem.

Bob Randall wrote:

I had a small problem with a Spyder 3 and the usb connection. As a result, I searched for similar problems and notice a trend regarding only the iMac late 2013 model that had a fusion drive and was running Maverick. There have been many returns of this model with the exchanged units having exactly the same problem.

You can read about it here:

Massive problem with audio interface: Apple Support Communities

and here:

Forum - Main Forums : Mac Music - Sound On Sound

Audio problems with new iMac Fusion Drive - MacRumors Forums

Potential audio problem with new iMacs - Page 3 - Gearslutz.com

Some have reverted to Mountain Lion, problem resolved.

Reverted to usb 2 drivers, problem solved. A few have booted from another source with no problem.

The only reason I kept Mavericks on the one computer was just to see when the problems would be fixed.

I can easily see it being the new OS. Most of these issues didn't occur with the previous Mountain Lion. I like the new features, but I have to have the other stuff working too. Devices working are more important than added features.

vockman wrote:

I was just going on this forum now to post my problems with my new 2013 Maverick 27" I7 Imac with fusion drive.

I have experienced intermittent problems with SD cards not being read properly and needing a repair, freezes when transferring files from the SD card onto the internal drive or an external usb 3 enclosure with SATA drives. Also Sleep/wake and accidental ejection problems with my external USB drive. Then I also have to clear these ghost files from the freezed copy attempts from the destination folder or Lightroom says it is looking for the previews.

So far the only thing I have found that helps is copy only 300-400 files at a time. Freezing seems to occur most when transferring 500+ files

As you said there are all sorts of complaints about similar issues on forums with different variations, including issues with WD drives, so your explanation makes the most sense: There is a global USB 3 bus issue within the mac.

So I am probably wasting my time thinking it is a problem with either the internal sd card slot or my external USB3 sata drive enclosure.

I don't see why it would be fusion drive related, it sounds like it is either a Maverick or firmware issue. However I do notice inconsistencies in the time it takes for the fusion drive to wake up.

If others can confirm this issue and offer solutions that would be great.

IT FREAKS ME OUT TO TAKE A CARD FROM A SHOOT AND GET A FREEZE WHEN DOWNLOADING THE ORIGINAL RAW FILES. WHAT IF THE CARD GETS DAMAGED?

ALSO THE TIME TO SECURELY TRANSFER THE INFO UNDER THESE CIRCUMSTANCES IS MAKING MY NEW COMPUTER BARELY MORE EFFICIENT THAN MY OLD ONE AND I AM RISKING LOOSING DATA!

You have had some of the same issues that I was researching.  My sd card that was in the iMac slot would become "unmounted" and I would get the warning message and also my usb spyder would randomly lose connection.

The fusion drive is a constant much like Maverick is.  The straight SSD model or a partitioned model does not experience the same common problems that were talking about here.

brycesteiner wrote:

Bob Randall wrote:

I had a small problem with a Spyder 3 and the usb connection. As a result, I searched for similar problems and notice a trend regarding only the iMac late 2013 model that had a fusion drive and was running Maverick. There have been many returns of this model with the exchanged units having exactly the same problem.

You can read about it here:

Massive problem with audio interface: Apple Support Communities

and here:

Forum - Main Forums : Mac Music - Sound On Sound

Audio problems with new iMac Fusion Drive - MacRumors Forums

Potential audio problem with new iMacs - Page 3 - Gearslutz.com

Some have reverted to Mountain Lion, problem resolved.

Reverted to usb 2 drivers, problem solved. A few have booted from another source with no problem.

The only reason I kept Mavericks on the one computer was just to see when the problems would be fixed.

I can easily see it being the new OS. Most of these issues didn't occur with the previous Mountain Lion. I like the new features, but I have to have the other stuff working too. Devices working are more important than added features.

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Make it a Great day!

posted on Gearslutz.com......today:

"Just to chime in here I had the exact same issue with a new iMac and a 1TB fusion drive, Mavericks and a Scarlett 2i2 USB interface. Since moving to the 10.9.2 beta the issue has gone!

So just to reassure folks 10.9.2 should fix it. One little note, initially after moving to 10.9.2 the issue remained, but if you're using a Scarlett interface you need to use the class compliant drivers. Once I switch to those all was good."

I have a 27-inch, late 2013 iMac with a 1TB fusion drive. I was having some strange system freezes which I attributed to using USB 3.0 hubs. I changed to an Anker 7-port USB 3.0 hub and my problems have disappeared. An advantage to the Anker hub is that it has two additional ports for charging smartphones and tablets.

I have read that there are problems on the use of USB 3.0 hubs that affect PCs as well as Macs. One issue is the amount power that is available for peripherals that require it. The Anker hub has a relatively large "brick" and can supply up to 48 W of power.

I seem to not have problems if I only copy about 300 raw files at a time from my SD card slot to my external USB3 drives

Are you limited if you transfer the problems to an internal drive?

Tom_N wrote:

vockman wrote:

IT FREAKS ME OUT TO TAKE A CARD FROM A SHOOT AND GET A FREEZE WHEN DOWNLOADING THE ORIGINAL RAW FILES. WHAT IF THE CARD GETS DAMAGED?

Many SD / SDHC / SDXC cards have write-protect switches. These are not binding on the computer or card reader, but you could put your cards into "write-protect" mode before putting them into the iMac and hope that the iMac would honor it.

Tom hit it on the head. I have a 2013 (late) 27" iMac. Because you have to reach around to insert or remove an SD card on the back of the machine, you are exerting a sideways thrust on the card. In about 30% percent of my card uses, the lock switch get dislodged and set to LOCK.

No fun. You just need to go slow and be careful.

I have a Late 2013 iMac, but with a standard hard drive, and also suffer with USB3 issues - which were summarily dismissed in this forum as other equipment problems.

On mine the issues is random disconnects after waking from sleep. A little Googling finds that this isn't actually limited to Macs, but also pops up on Windows boxes too.

You can simply drop to USB2 speed by using a USB2 cable.

FWIW, I gave up for now, and use a Thunderbolt to FW800 adapter, which is working perfectly well.