USB 3.0 speeds on late 2012 iMac

[lcavada]

This has been explained to you many times yet you ask again, the HD is the weak link and you will NOT see any improvements with Thunderbolt, you have a HD inside, if you want higher speed buy an SSD!

thanks. Note that i was looking for alternative ways to improve this bottleneck.

A few posts down you will notice thedeske mentioned UAS as an alternative. this uses a platter disk, but can get much faster speeds.

So my persistent questions got results.

----------

Late 2012 and 2013 Macs are capable of 200 per second on HD with the right USB3 single external enclosure via a new UAS protocal. Lacie, Caldigit, and a few others have this in some of their products. I personally witnessed 200 up and down on a recent install with an iMac & Caldigit AV Pro external. The same device loaded with SSD reaches over 400. http://www.barefeats.com/hard162.html

UAS first arrived on a few PC boards mid 2012
Not a peep from Apple on this, but it's there.

THANKS.

This looks excellent. Pricing is not that bad either !!

I will look at these devices. I could not find the CalDigit Drive utility so i can check the speeds that i have now. I wonder where i can get it.

Will these drives work at top speeds on my late 2012 iMac?

 

[thedeske]

THANKS.

This looks excellent. Pricing is not that bad either !!

I will look at these devices. I could not find the CalDigit Drive utility so i can check the speeds that i have now. I wonder where i can get it.

Will these drives work at top speeds on my late 2012 iMac?

Yes, the late 2012 iMac has UAS support. The retina MBPs do as well & anything in 2013.
The utility only works with their drive. I didn't spend very much time with it. There are others, like AJA. I talked about these in another string here. They are on a client's system I installed for Lightroom work. The USB only version is 30-40 less I think. We bought both.

Again, I wonder why Apple is so quiet with this. I can't be the only one who remembers the days when they'd never let a performance boost like this go unnoticed.

Here's another review - http://caldigit.wordpress.com/2012/12/13/av-pro-an-editors-perspective/

 

[monokakata]

The OP's speeds seem low to me. I don't know why, but I don't think it's as simple as using a rotating disk.

I have a USB3 enclosure (NewerTechnology Ministack) with a 3 TB Seagate 7200 rpm drive in it. It has about 500 gb free.

CalDigit USB3 interface.

I just ran BlackMagic (5 gig file) and got in the high 120s for both read and write.

I have the exact drive (hardware and contents, because the external's a clone of the internal) in the Mac Pro, where as an internal it gets in the high 170s R and W.

I connected a Macally USB3 enclosure with a 2 TB Hitachi 7200 rpm drive (several years old) in it to the same interface. About 400 GB free. BlackMagic gave me about 100 W and 110 R.

Just for fun I plugged the Macally into a USB2 port, and got 30 W and 40 R. The Newer Technology enclosure/Seagate combo ran at the same speed (30W, 40R).

It seems clear, then, that at USB2 speeds the interface is the limiting factor, while at USB3 speeds it's the disk. But even if it is the disk in my case, even my slower disk/enclosure is a lot faster than the OP's. That needs an explanation.

True, I ought to swap the Hitachi and the Seagate, and see what happens back on the CalDigit interface, but I'm not going to unless somebody wants me to complete the logic.

 

[Ppq]

Looking around, did not see a price for this case. It appears to be a single drive case.

thanks

yes, it is http://www.i-tec-europe.eu/?t=3&v=144 this one price was about 35 EUR.

 

[thedeske]

Should be obvious that the quality of external housings is all over the map. It might say Super Speed, but that does not necessarily make it so in every chip set. The battle of the chain (drive, hub, cable) matters, and a cheap case is a cheap case

 

[Nuke61]

It seems clear, then, that at USB2 speeds the interface is the limiting factor, while at USB3 speeds it's the disk. But even if it is the disk in my case, even my slower disk/enclosure is a lot faster than the OP's. That needs an explanation.

In post #18 the OP said he was getting 75 MB/s... still slower than your drives but well above USB 2.0 rates. Just sounds like a slow drive to me. I'm using OWCs portable SSD (don't remember the name) via USB 3.0 and get ~350 MB/sec read speeds.