From: Milton Aupperle <milton@outcastsoft.com>
Date: June 20, 2012 11:53:52 AM MDT
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] Re: VT and USB 3
Hi John;
On 20-Jun-12, at 10:32 AM, John wrote:
Hi Milton,
Thanks for the update.
No problem.
Sonnett has a USB 3 card with very poor reviews and also only supports mass storage data transfer as you indicate for Caldigit. In addition, it fails to support any USB 1.0 or 2.0 devices.
Apple (personal contact) says their built in USB 3 ports will support USB 2 and USB 1.1 devices, so at least things like the GPUSB and USB to serial devices should continue to work.
Caldigit does support USB 2 drives. The interesting part is Caldigits driver far surpasses Apples USB 2 driver for throughput on a USB 2 drive.
For example, using the same Iomega USB 2 one terrabyte drive for copying data (large file sets of 5+ gigabytes in size) from my Mac Book Pro 2010 17".
When used with Apples built in USB 2 ports, I get sustained transfer rates of 22 megabytes per second - doesn't matter if I'm using Leopard, Snow Leopard or Lion - rates remains the same. That rate is also nearly the same on multiple Mac models too +/- 2 megabytes per second.
If I restart and use BootCamp for Windows 7 on the MBP 17", I get sustained transfer rates of 32 megabytes per second with that USB 2 drive. So same drive, same computer, same ports - different OS and I get 50% faster throughput.
If I boot into Snow Leopard, insert the Caldigit USB 3 card and then attach the USB 2 drive to the Caldgit USB 3 card, I get sustained transfer rates of 32 megabytes per second.
So as you can see, Apple appears to have done a poor job optimizing their USB 2 drivers and both Windows and Caldigit beat them by 50%. So I really wonder if USB 3 will get the same poor optimization treatment or not.
When using the Caldigit USB 3 card with a cheap USB 3 three terabyte hard drive (Seagate Flex Go model), I was getting sustained transfer rates of 80 megabytes per second when stacking the remaining ~56 gigabytes of Venus transit movies. The internal 5400 rpm drive (replaced by Apple under warranty last week), hits 50 megabytes per second top rate on the MBP 17".
USB 3.0 is new on the Mac. I'm hoping for more development / updating over time. 3.o support would be a nice option to have going forward.
The only ones who may offer full USB 3 support will hopefully be Apples new Macs. And until Apple documents there new APIs, it isn't not worth doing anything more.
Lastly, sales of Astro IIDC do not justify spending several thousand dollars on new Macs just for USB 3 camera development - even if I get loaner cameras from PGR. That's just the economics of things. Maybe in a year or two, but right now not going to happen unless a huge swell in sales occurs.
TTYL..
Milton Aupperle
Best wishes,
John B.
--- In Astro_IIDC@yahoogroups.com, "milton_aupperle" <milton@...> wrote:
Hi Folks;
Just an update on USB 3 Camera support.
As it turns out, the Caldigit USB 3 Express card only supports Mass Storage class devices for USB 3 and 2.
It will cause a Kernel Panic is you try and use it for generic USB Bulk transfer requests for USB 2 cameras.
I specifically asked is Caldigit if they supported other USB 3 devices including USB 3 cameras for USB 3 access. They said yes back in October 2010. Their support now states no they don't support anything except Mass Storage devices like Hard drive and Card Readers, so I'm out $110 as their card is useless for my intended purposes. None of the other USB 3 cards work any better either.
So short of buying a new 2012 Mac Book to develop for USB 3, this is dead for USB 3 access.
Also, Apple has finally mentioned a few things about USB 3 support on the USB List. They are only supporting their own USB 3 hardware on Lion or higher - so no Generic xHCI USB 3 support at all - especially over Thunderbolt.
They have no documentation for USB 3 other than saying there are a few new USB 3 specific API's. Until Apple is forth coming on more information, USB 3 support for cameras on the Mac is in Limbo.
TTYL..
Milton Aupperle
--- In Astro_IIDC@yahoogroups.com, "milton_aupperle" <milton@> wrote:
I have more testing to do with the Card, but I'll likely contact Point Grey Research early next week and see if I can get a USB 3 loaner camera sent out for testing.
So with any luck we Mac users will have access to USB 3 cameras going forward.
TTYL..
Milton Aupperle