Canon EOS slowing or Jamming when taking continuous pics

[Marshpike]

Firsty going to have to apologise as although I've had m camera for 1.5 years I'm a little wet behind the ears with it.

I have an EOS70D with a Canon Zoom Lens EF 70-300mm 1:4-5.6 L USM lens, and I never take the hood (mentioning incase its relevant).

I use the camera to take pics at the local running races which I've been doing since I've had the camera but recently the camera seems to be jamming up, not sure if its struggling with focus, but it starts off good then half way through the pack of runners its stops for a rest before letting me take another single snap or two then needs a rest??

I haven't a clue what's causing this as its never happened in the past, takes great photos for the first few minutes before this starts to happen, apprecaite any ideas>???

[jrhoffman75]

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.”

[wq9nsc]

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

[Waddizzle]

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@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.”

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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.”



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.