A warning about UHS-II cards in the 5D4 (and other UHS-I cameras)

I've already seen reports from some 5D4 shooters having 4K video problems when using high speed (e.g. 280MB/s) UHS-II SD cards in the 5D4.

It seems (http://www.cameramemor​yspeed.com …ii-32gb-sdhc-memory-card/) that some UHS-II cards will only support a UHS-I fallback mode at that interface's lower bus speed; which means a 50MB/s max performance (not enough for the 5D4's 4K video rate).

In summary - it means that a 95MB/s UHS-I card will likely be better for a UHS-I camera than a theoretically faster UHS-II card.

PS If you're currently rolling around on the floor about the fact the 5D4 is using "old" tech, note that the UHS-II capable D500 was getting 138MB/s from a claimed 280MB/s UHS-II card (that was giving 226MB/s writes in a UHS-II card reader). I.e. it appears that there's maybe not quite the gulf in performance you'd expect - though that is the only test I've seen; other cards and other UHS-II capable cameras may do better.

Great post! Also consider reading the 5DS review: http://www.cameramemor​yspeed.com …ds/sd-cf-card-comparison/

It appears this series Sandisk UHS-1 Extreme PRO is the one they are referring to: https://www.amazon.com …UYAY?_encoding=​UTF8&psc=1

$123 for a 256GB card.

The Lexar 2000x card found here: https://www.amazon.com …-1&keywords=lexar%2B200​0x

$229 for a 128GB card but offers 280MB/s read speeds to the computer.

I have the Lexar 1000x SDXC UHS-II card and it does not support SDR104 speeds when inserted into a UHS-1 slot camera (5Ds/5D4). Per the review: http://www.cameramemor​yspeed.com …ii-64gb-sdxc-memory-card/

So here it is my fast and common found card is actually slow on the 5D4 and does not allow any 4K video to the card due to the 500mbps video bitrates.


Myself... I'll stick to the Sandisk Pro UHS-1 card.

Since the 5DS has the same UHS-1 spec based on his review: http://www.cameramemor​yspeed.com …ds/sd-cf-card-comparison/

The fastest SD cards got 71MBs so the D500 getting 138 is still twice as fast. Pretty substantial.

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All of this could have been squashed had they gone with cfast...

jonneymendoza wrote in post #18125270
All of this could have been squashed had they gone with cfast...

True. They cut the balls off at the 21 frame buffer. They were lazy and stuck the same 5DsR/5D3 hardware and only upgraded the software bus interface to the UHS-1. Cfast and UHS-II would of been fantastic... Cfast would of ensured unlimited buffer. They won't make the 5D4 best at anything but jack of all trades and it shows in the memory interface they decided to stick with. "Good enough" not great.

For me... I doubt I'll ever worry about the buffer but I'll know more after tonight/tomorrow with first two baseball games. Will report back after then.

Honestly nothing has changed... canon has always put a 3 second buffer on all their cameras including up till recently the 1D series. The 1DXII is the first to extend that to ALOT.

jonneymendoza wrote in post #18125270
All of this could have been squashed had they gone with cfast...

And so would your wallet (but, yea, CFast would have been nice)

I posted this in the discussion group but it's valuable enough to post here as well:

OK my 256GB Sandisk UHS-1 Extreme PRO SD card arrived and 4K works fine AS mentioned by a few others.... recorded 5 minutes worth of 4K video with only that card in the camera no issues. This is the card I bought: https://www.amazon.com …asin?_encoding=​UTF8&psc=1

SD only Raw = 30 images
lexar 1066x CF only Raw = 35 images
SD & CF RAW to both cards = 30 images
SD & CF Raw+JPG to both cards = 19 images

This truly is the fastest SD card available for a really good reasonable price. Whats also amazing is seeing 5592 RAW images available on the top LCD... This is a big card lol. Test was set to 1/8000, ISO 100 F4 and manual focus on the lens. All internal processing was disabled (NR, lens optimizer, etc) Obviously real world results can vary but this is a controlled test. The 5D4 buffer CAN be beat by both CF slot AND the SD slot.

Buy the right SD card!

I wish Canon would have done what Nikon did, and build the body with an interchangeable card reader.

Imagine the possibilities:

CF+CF
CF+SD
SD+SD
CFast+CFast
CFast+CF
CFast+SD
XQD+XQD
XQD+CFast
XQD+CF
XQD+SD

Of course it might not be necessary to build all of those reader configurations, but even just a few would help future-proof the body, and would give Canon something else to sell us!

My other wishlist items include USB type C instead of USB 3.0

Even so, I'll be getting the 5D Mk4 in the near future.

Is it true that you can only record to one card when shooting video?

If so, I'll just keep using CF cards and not worry about the SD limitations.

Jared5 wrote in post #18131953
Is it true that you can only record to one card when shooting video?

If so, I'll just keep using CF cards and not worry about the SD limitations.

Yes only one card at a time. But I shoot 4K to the SD slot due to the sizing.

Talley wrote in post #18136389
Yes only one card at a time. But I shoot 4K to the SD slot due to the sizing.

I shoot mainly stills, but wonder if video shooters feel ripped-off that they can't make use of the dual card body for video.

Would an extra 10ish MB/sec help?
https://www.amazon.com …04MB-Memory/dp/B01513KDDO

MedicineMan4040 wrote in post #18144016
Would an extra 10ish MB/sec help?
https://www.amazon.com …04MB-Memory/dp/B01513KDDO

The specs on that say: UHS-3 SD technology facilitating up to 104MB/s read speed and 70MB/s write speed*

For stills, 70MB/s is good but you have other issues with that one:

for 4k video, you need at least 90MB/s — make sure you’re looking at WRITE speed

Not to mention that’s a UHS-3 - and I believe the 5D4 expects UHS-1

MedicineMan4040 wrote in post #18144016
Would an extra 10ish MB/sec help?
https://www.amazon.com …04MB-Memory/dp/B01513KDDO

planet5D wrote in post #18144103
The specs on that say: UHS-3 SD technology facilitating up to 104MB/s read speed and 70MB/s write speed*

For stills, 70MB/s is good but you have other issues with that one:

for 4k video, you need at least 90MB/s — make sure you’re looking at WRITE speed

Not to mention that’s a UHS-3 - and I believe the 5D4 expects UHS-1

I think it's a typo: as far as I'm aware there's only UHS-I and UHS-II as interface standards (https://www.sdcard.org …pers/overview/b​us_speed/), but the U3 bit refers to the speed class (https://www.sdcard.org …ers/overview/sp​eed_class/).

The interface governs the maximum speed that could ever be possible with any card. The speed class is a way of advertising how quick a particular card is (likely related to the quality of the flash chips inside the card).

For that GOBE card; assuming the numbers check out then they're actually being useful/honest - i.e. telling you that the write speed will be lower than the read speed (quite common). As opposed to giving you a single number, and staying quiet about the fact that's actually the read speed.

104MB/s is the limit for the UHS-I interface, so I guess they're claiming the flash inside that card (and the internal controller) will max out the interface for reads. What I don't know is whether a good SanDisk 95MB/s card will actually write quicker than the GOBE's claimed 70MB/s. This (http://www.cameramemor​yspeed.com …ro-32gb-sdhc-memory-card/) would indicate yes; so probably the right SanDisk card would be the better choice (albeit giving up a small amount of read speed - assuming the GOBE actually hits 104MB/s in a card reader).

I understand the 5D4 4K data rate is around 500Mbps (about 63MB/s); so in theory the GOBE should just be fast enough if it hits the claimed number. The data for the 7D2 and 5Ds on the above link would indicate the right SanDisk UHS-I card would be OK though.