Canon Community Canon Community
 


Reply
Honored Contributor
Posts: 7,789
Registered: ‎11-13-2012

Re: Canon EOS slowing or Jamming when taking continuous pics

From SanDisk

 

“Ultra High Speed Phase II (UHS-II) bus design for SDHC and SDXC was added in SD spec 4.0. This is an additional design enhacement with connector interface modifications to increase performance.

UHS-II specification defines bus architecture for options of 156MB/s and 312MB/s. Manufacturers implemented the 312MB/s option in memory cards. These are theoretical maximum limits and actual maximum performance for a specific card is defined on the label or in advertising.

Host devices will obtain the maximum UHS-II speed when both the card and the host device support UHS-II. Otherwise, the host device and card will use the highest compatible UHS-I or SD bus speed.

There is no compatibility problem using a USH-II card in a UHS-I or non-UHS device.”

John Hoffman
Conway, NH

1D X Mark III, Many lenses, Pixma PRO-100, MX472, LR Classic
Respected Contributor
Posts: 1,349
Registered: ‎01-25-2018

Re: Canon EOS slowing or Jamming when taking continuous pics

In general, when possible I try to stick with accessory devices that are explicitly designed to match the standard of the product to which they are being paired.  As anecdotal information, USB 3.x memory "sticks" are supposed to be fully backwards compatible with devices designed for USB 2.0 yet a variety of different manufacturer USB 3 sticks create intermittent problems when used with the infotainment system in my 2018 GMC Denali heavy duty pickup while USB 2 sticks perform flawlessly.

 

There are big performance differences between different memory cards of supposedly identical specs which is why I suggested choosing a memory card from the link I posted earlier in the thread that tested the actual performance of several different cards in the specific camera. 

 

Some of the most egregious examples of this sort of performance difference are found in some current Cfast cards where components designed for a regular CF card are being used to produce cards that fit into a Cfast slot but produce performance that doesn't even equal that of a regular good CF card in a CF slot.

 

Rodger

EOS 1DX M3, 1DX M2, 1DX, 5DS R, 1D M2, EOS 650 (film), many lenses, XF400 video
VIP
Posts: 11,405
Registered: ‎08-13-2015

Re: Canon EOS slowing or Jamming when taking continuous pics


@jrhoffman75 wrote:

From SanDisk

 

“Ultra High Speed Phase II (UHS-II) bus design for SDHC and SDXC was added in SD spec 4.0. This is an additional design enhacement with connector interface modifications to increase performance.

UHS-II specification defines bus architecture for options of 156MB/s and 312MB/s. Manufacturers implemented the 312MB/s option in memory cards. These are theoretical maximum limits and actual maximum performance for a specific card is defined on the label or in advertising.

Host devices will obtain the maximum UHS-II speed when both the card and the host device support UHS-II. Otherwise, the host device and card will use the highest compatible UHS-I or SD bus speed.

There is no compatibility problem using a USH-II card in a UHS-I or non-UHS device.”


I have never heard that before about UHS-II card compatibility modes.

 

Maybe some brands are able to do that.  I have always had the impression that “UHS-I Compatibility Mode” meant transferring data at, or near, the minimum speeds defined by the selected operating mode.  

This is a screenshot from th 80D Instruction Manual.  It reads “UHS-I cards are supported.”

9BBAAC62-780D-4A7B-8399-45987D00F80F.jpeg

While current Canon DSLRs can support UHS-I mode, I am not certain what operating mode would be in effect with the a UHS-II card.  Nowhere do I see where UHS-II is supported, and I suspect that the native mode for the SD slot may not necessarily be the UHS-I mode.

----------------------------------------------------------------------------------------------------------------------------------------------------------

"Doctor told me to get out and walk, so I bought a Canon."
powered by Lithium

LIKE US on Facebook FOLLOW US on Twitter WATCH US on YouTube CONNECT WITH US on Linkedin WATCH US on Vimeo FOLLOW US on Instagram SHOP CANON at the Canon Online Store
© Canon U.S.A., Inc.   |    Terms of Use   |    Privacy Statement