Fastest Card Reader?

[Carl Stone]

From Apple.

 

""The Power Mac G5 computer has three external Universal Serial Bus (USB) 2.0 ports on

the back and one on the front of the enclosure, providing support for high-speed (480

Mbps) devices using an Enhanced Host Controller Interface (EHCI). Ports are automatically

routed to a companion OHCI controller (that complies with the OHCI specification) when a

classic-speed (full-speed or low-speed) USB device is attached to a root hub port.

The external USB ports are off of the USB 2.0 controller connected to the PCI bus, bridged

by the South Bridge IC. In addition, there are two USB 1.1 ports on the keyboard, which are

used for connecting the mouse as well as additional I/O devices such as printers,

scanners, and storage devices.

 

The Power Mac G5 computer provides 5 V power for the USB ports and up to 500 mA on

each port. The power is provided in both run and sleep mode. The ports share the same

power supply; a short circuit on one disables all ports until the short has been removed."

 

 

 

and this:

 

"Topology

USB is described by the standard as a tiered star bus topology. The bus controller in the

host computer provides a root hub, which is considered the first tier. From that root hub,

each cable hop connects at the second tier to either a function (a peripheral device such as

a keyboard or mouse) or another hub, which can connect at the next tier to additional

peripherals and hubs. Six tiers are allowed in addition to the tier represented by the root

hub, and hubs are not allowed in the seventh tier. Consequently, a maximum of five hubs

are allowed between the root hub and a peripheral device. Note that a physical device can

include more than a single function, as in the case of printer/scanner/fax machines, and

can also include a hub, as in the case of many Apple keyboards.

 

Protocol

The USB host controller is considered the bus master; it manages data transfers between a

source and a destination using a pipe, a logical construct that comprises the

configuration, control, and status parameters that define the connection between that

source and destination. A special type of pipe, referred to as a default control pipe, is

established for the zero endpoint in each device when the device is connected to the bus.

Default control pipes are managed by the host controller for bus control purposes and are

not visible to client software. Each device reports its configuration information when the

host detects the device connected and powered up on the bus. Other pipes can then be

created, as required by the class and features of that device. These other pipes are also

managed by the host controller but can be used by client applications to access device

features. For more information about device classes, see the USB Class Specification

documents available from the USB Implementers Forum

websitehttp://www.usb.org/developers/devclass/.

 

The host controller manages all transactions, and most transactions involve transmission

of three packets. To initiate each transaction, it polls devices on the bus (at a scheduled

interval) by sending a token packet that identifies the address of the device, the endpoint

number that specifies the target function, the transfer type, and whether the transfer is

directed toward the root hub (upstream or in) or away from the root hub (downstream or

out). Then the source (depending on the transfer direction) sends to the destination either

a data packet or an indication that there's no data to send. The destination typically

responds with a handshake packet that indicates success or failure of the transfer.

 

Concentration of control functions in the host allows simpler devices, but imposes limits

on bus throughput. This protocol is effective for minimizing bus control overhead."

 

From Rob Galbraith. BTW Sandisk has a new Extreme Ducati line that's faster than the

Extreme IV.

 

http://www.robgalbraith.com/bins/multi_page.asp?cid=6007

[godfrey]

Carl,

 

That's a nice high-level system design description that means very little without a lot more

information. I used to write those.

 

See my previous response.

 

Godfrey

[wadleigh]

Ok I'm not really needing that level of detail about the Apple computers.

 

I just performed 3 tests using the HD Tune utility that was mentioned above and here are the average transfer rates:

 

Internal card reader = 0.8 MB/sec

External card reader = 2.4 MB/sec

External USB Harddrive = 18 MB/sec

Internal Harddrive = 50 MB/sec

 

On Wikipedia it nicely describes 3 different data rates for USB.. I copied it below. It seems my card reader is the Low Speed, right?

 

* A Low Speed (1.1, 2.0) rate of 1.5 Mbit/s (187.5 kB/s) that is mostly used for Human Interface Devices (HID) such as keyboards, mice, and joysticks.

 

* A Full Speed (1.1, 2.0) rate of 12 Mbit/s (1.5 MB/s). Full Speed was the fastest rate before the USB 2.0 specification and many devices fall back to Full Speed. Full Speed devices divide the USB bandwidth between them in a first-come first-served basis and it is not uncommon to run out of bandwidth with several isochronous devices. All USB Hubs support Full Speed.

 

* A Hi-Speed (2.0) rate of 480 Mbit/s (60 MB/s).

[Carl Stone]

'I probably know the person whom you're referring to as well, since my job was to talk to the

third party hardware and software vendors, assisting them when they ran into development

problems.'

 

Possibly, but he hasn't given me permission to reveal his identity to this forum. He's also

retired from Apple, and doing his own thing. He might well say that he knows you, which is

at least as credible as your claim to know him. And all of this knowing proves.......?

[godfrey]

Carl,

 

If you want to believe what you want to believe, fine with me. It's irrelevant. You're wasting

the OP's time with this nonsense. He's got a Windows system.

 

Godfrey

[Brad_]

>>> He's got a Windows system.<P>

 

Redemption is <i>always</i> available...

[wadleigh]

No help on finding a tool to determine USB 1.1 or 2.0? Please see my posting above with timings for my USB card reader (internal and external). Are these REALLY bad or what??? What is going on with my desktop!?!?

 

Any ideas to check?

[wadleigh]

I ended up figuring out why my computer downloaded photos so slowly! I wanted to share this information with you all because I thought it was helpful.

 

So here is the low-down..

 

How you can determine what USB ports are 2.0 and which are 1.1 on your system. Here's the article I found to guide you on this. To add to this article, in Device Manager select "View -> Devices by Connection" and look for those devices you have connected to USB 1.1 and USB 2.0 Hubs! You might be surprised about what you learn. The USB 2.0 hubs say something like "USB2 Enhanced..." and the USB 1.1 Hubs say just "USB Universal...".

 

http://www.tech-recipes.com/rx/1553/xp_vista_usb_2_0_detect_system_usb2

 

I determined that my entire internal card reader is hooked up to a 1.1 USB Hub inside my computer which really makes me mad that the company did this when 2.0 was available and should have been used for optimal speed. So I disabled all of these ports and will only use my external card reader on USB 2.0 ports. I didn't realize it, but I was also plugging my external reader into a USB port that was hooked to the USB 1.1 hub as well! Ugh!

 

Also a VERY great program that helped me determine transfer rates of each port was one that was recommended to me called "HD Tune". Search for it on google and you can easily find it and download the free version. It allows you to pick a drive and do a transfer rate test. For card readers, you need to stick a card into the slot before you run the program - then select the card slot and start the test. You can pretty much see the average speed really early without having to wait for it to finish. For USB 1.1 you might see either 0.8 MB/sec or 1.5 MB/sec depending. For USB 2.0 you should see at least 25 MB/sec! Of course this is affected by the speed of your card but it won't change too much for the average cards. My cards were Ultra II and Ultra III 2 GB.

 

So now my photos download really fast - whew.

 

Hope this is useful to some of you - it was painful for me but I am now much happier that I know.

 

John

[curt wiler]

Patrick - sorry I didn't catch your comment earlier "I personally copy it on a folder call RECEIVE, and set Lr to get any file in there as AUTO IMPORT, not applying setting or creating preview..as that would have too much time during a import for sure."

 

The good thing about this is that the relatively slow LR process can run on the day's work without operator attention, whereas the import requires that you feed the cards manually. It makes a difference when you are working away from home, trying to eat and sleep, etc.

[curt wiler]

John - very good work, and a reminder that time marches on and the technology changes. It prompted me to look into a UDMA-enabled ExpressCard for my notebook that saves precious minutes over last year's model.