CCC - markedly different BU times - why?

I've been using Carbon Copy Cloner on my MBPro (specs in signature) & iMac (specs below), purchased in March & April 2013, respectively. Cloned both HDs today - on the iMac the process took over 40 minutes and transferred just under 2 GB of data (3rd clone); however on the MBPro the process took less than 5 minutes w/ over 3 GB of data (also 3rd clone).

Now both machines have USB 3.0 and I'm using an OWC external HD w/ a partition for each computer, so the external drive, cable, and USB standards are identical. The only difference that comes to mind is the 1 TB Fusion drive vs. the 256 SSD, i.e. is it just the solid state electronics making the difference or should I look for other issues? Thanks - Dave


iMac 21.5" display
OS X 10.9.1
2.9 GHz Intel Core i5
16 GB 1600 MHz DDR3
NVIDIA GeForce GT 650 M 512 MB
Fusion Drive 1 TB

Think you have hit the nail on the head with the SSD.

harryb2448 said:

Think you have hit the nail on the head with the SSD.

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Thanks Harry - I realized that the SSD cloning would be faster but 10x seems a little outlandish to me? So, just wondering - hopefully others who are using CCC on similar machines will 'chime in' and make the same observation - might try to contact the CCC developers to get their opinion - will post back if they respond. Dave

SSDs are blindingly fast, to the point that the bottleneck is usually the connection to the drive but you have eliminated it. I would expect the SSD to be faster, but 10x is startling. Depending on the settings in CCC, it's possible that what CCC did is to copy over ONLY what was changed since the last backup. That's how I have CCC set up, and I also ask it to archive what it replaces so that I end up with something similar to Time Machine in that I can go back in the archives to get to an older file if I have to. Could that be it?

It is not possible to compare the time frame of clone backups on two different machines.

How much used space on each machine? How much has changed on each machine since the last backup? The backup process does not only transfer data. It compares the source drive to the backup drive which means verification of all data on one vs the other - it also includes deletion of data no longer on the source drive and associated cleanup...

Thanks for the additional comments - we really don't add a lot on these computers and the iMac had about a GB less data transferred (vs. my MBPro) - weird behavior to me - WELL, I left a contact email at the CCC site and hopefully they will respond - will post back if so - of course, my main concern is whether my iMac is the problem (had a fan issue that I posted in another thread) - thanks again - Dave

Also Dave adverse comments abound on Fusion Drive and Mavericks.


Fusion SSD very slow with Mavericks - MacRumors Forums

harryb2448 said:

Also Dave adverse comments abound on Fusion Drive and Mavericks.
Fusion SSD very slow with Mavericks - MacRumors Forums

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Hi Harry - yes, I've become more aware of the issues w/ Apple's fusion drives (should have read up more in the spring before I selected that option) - not sure if these 'problems' are hardware or software related primarily, at least if more the latter OS upgrades may help?

I looked at the link provided and most of the comments seemed to be in setting up one's own hybrid drive using either an internal or even an external SSD - not much discussion of the Apple fusion drive but will do some more searching & reading. I do have Apple Care & a local store (where we bought the iMac), so I feel comfortable about obtaining help if needed.

Dave

Just for those also wondering about backup times on different computers w/ CCC - I emailed them and received the reply below the next day from Rob Compton - the link is to their FAQ topic that addresses this issue.

This is an excellent review of the factors that go into the timing of cloning a HD or SSD (or a fusion hybrid) - not sure that it answers my questions as to the 10x difference discussed previously? I suspect that this is likely related to my faster SSD on the MBP and possibly issues with reading/writing from the fusion drive on the iMac to my BU partition.

Dave

From: Rob Compton (Bombich Software support staff)
Subject: BU Time on an iMac w/ fusion drive vs. MBPro w/ SSD - dramatic
difference?

Dave,

There are a lot of factors that can affect performance. We cover the basics
here:
How long should the clone or backup take? / Frequently Asked Questions and Troubleshooting / Knowledge Base - Bombich Software Support

RAM, running apps, other utilities can all come into play.

Best wishes,
Rob

Rob Compton
Bombich Software, Inc.
Mac Backup Software - Carbon Copy Cloner

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