Author Topic: Canon 5D Mark III / 5D3 / Firmware 1.2.3  (Read 1055921 times)


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Re: Canon 5D Mark III / 5D3 / Firmware 1.2.3
« Reply #1600 on: October 28, 2019, 01:28:19 PM »
Is this card defective or am I using the wrong settings?

Had the same issue with Komputerbay 64GB 1000x. Solved by properly formating in a UDMA-7 capable reader (with USB 3.0). You can also try to low-level format inside the camera, might work.
If this doesn't work, I would assume you probably have a broken card.


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Re: Canon 5D Mark III / 5D3 / Firmware 1.2.3
« Reply #1601 on: November 01, 2019, 02:12:11 PM »
Tried formatting multiple times, using both ExFAT and FAT32. Similar results each time. Low level format in camera doesn't help unfortunately. Strangely, in crystaldiskmark, the benchmark results are significantly higher, (read and write 65-70MB/s) but still not to spec. I suspect a compatibility issue with the controller is making the 5D3 not use UDMA 7 and instead some slower mode. In any case, it's going back!

Walter Schulz

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Re: Canon 5D Mark III / 5D3 / Firmware 1.2.3
« Reply #1602 on: Yesterday at 09:47:04 PM »
I put it here ...
Found it via SLRlounge and the original blog post is linked:

Maybe a1ex can give a word or two. Minor error: 5D3 works with 166x (theoretical) as in UHS-I SDR25 mode (AFAIK).

Don't know if it's worth the effort to comment his blog entry ...
Photogs and videographers: Assist in proof reading upcoming in-camera help!. Your input is wanted and needed!


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Re: Canon 5D Mark III / 5D3 / Firmware 1.2.3
« Reply #1603 on: Yesterday at 10:06:19 PM »
Short answer: the two card slots are independent; there are two different controllers. The presence or speed of a SD/CF card does not affect the speed of the other card. You have, feel free to prove me wrong ;)

Of course, if you enable the option to save each image to both cards (in Canon menu), the slowest card (SD) will be the bottleneck. That's expected.

Or, if you attempt to write to both cards at the same time, the memory bus appears to be the bottleneck. Can be worked around, to some extent, e.g. by disabling "unnecessary" LiveView image streams.

One more thing. Most of the time, this is a hardware limitation and can not be solved with a firmware upgrade.

It can (with sd_uhs), as the hardware appears to be the same as in other DIGIC 5 models. Maximum speed is still an open question, if you ask me, but further investigation will probably require a good logic analyzer, rather than "blind" trial and error.