p.1 #1 · Best CF card for canon R5 Mark ii for wildlife and bird Photography
I’ve been going through the Canon manual and checking specs from different memory card manufacturers, and I have a simple question: what are the actual read and write speed limits of the camera body, and which memory cards can truly take advantage of the camera’s full capability? I don’t want to end up buying an ocean when the real requirement is just a pool of water, and I’d really appreciate some real-world guidance. For reference, I’m currently using Delkin Power cards (Delkin Devices 512GB POWER 4.0 CFexpress Type B Memory Card offers burst read speeds up to 3650MB/s and burst write speeds up to 3240MB/s in addition to a sustained write speed of 820MB/s. ) , which I’m quite happy with overall, but I do occasionally hit the buffer limit when shooting C-RAW in H+. Thanks in advance!
p.1 #2 · Best CF card for canon R5 Mark ii for wildlife and bird Photography
The Delkin Power cards are great. Just make sure you don't have your camera set to write to both cards simultaneously as a slower SD card will slow things down.
p.1 #3 · Best CF card for canon R5 Mark ii for wildlife and bird Photography
I don't believe any CFe 4.0 card will restrict the R5II's max write speed capability, which appears to be well below that of 4.0 cards, which is a reason why you're hitting the buffer.
As for actual figures, AFAIK, nothing has been officially released by Canon and this was a question raised prior to the R5II's release (whether it operated at CFe 4.0 speed). One could approximate the camera's card write speed by shooting a burst until the buffer clears, time the duration from first to last shot, then divide the total storage requirement for all the images by the time it took to write out the buffer.
I just did a quick test with black-frame CRAW files and it was 3230MB total and about 13 seconds from starting the first shot to the time the buffer cleared, which is about 250MB/s. If the camera actually doesn't start writing to the card until the buffer fills (it's unclear if this is the case with the R5II), the burst took about 4.5 seconds, meaning about 8.5 seconds to clear the buffer, or about 380MB/s to write to the card.
Whichever number is correct is kind of irrelevant for CFe because it's well below the sustained write capability of decent 4.0 cards. These figures though do straddle the typical maximum write speed of V90 SDXC cards.
I have not carefully evaluated the performance impact relative to buffer clearing time when shooting to just CFe vs CFe and SDXC V90. For most of my events I write to both cards and have not noticed a significant impact in buffer clearance. Yes, it feels slightly faster with just CFe, however most of the time I prefer the redundancy of the second card. In this respect, for maximum performance, two CFe slots would have been better. And CFe cards are actually less expensive than V90 SDXC. But if speed isn't needed, there's no arguing the cost proposition of V30 and V60 SDXC, or the relative ease of finding SD cards in a pinch.
I only have a couple CFe cards because, like you, until recently I used the R6II. One is a mid-tier Angelbird 512GB that is CFe 2.0, which I bought in 2022 while evaluating the R3 and R5 in anticipation of transitioning to mirrorless. The second is a Nextorage 500GB NX-B3AE CFexpress 4.0 that I recently acquired for the R5II. Both work fine in the camera, I have observed no performance differences and I shoot a lot a 30fps. Both have been reliable. I got the Nextorage because it happened to be on sale at B&H at the time. I was unfamiliar with the brand but liked that it was founded by former Sony storage engineers. Kind of a similar story to that of Prograde Digital being started up by former Lexar management after Lexar was sold off. The card itself was made in Taiwan like a lot of other flash memory products.
p.1 #4 · Best CF card for canon R5 Mark ii for wildlife and bird Photography
Just following up a bit:
In the comment above, I tested CRAW at ISO 4000 because it made for a 'dirtier' black frame image that would be more comparable in size to a typical real image. The R5II manual indicates CRAW files average 20MB and buffer is 170 frames, which is 3400MB and quite close to my findings (though I have never hit 170 CRAW frames in the real world (meaning higher ISOs) when maxing out the R5II buffer). It took 13-14 seconds to shoot the sequence and for the buffer to fully write to the Nextorage CFe 4.0 card.
I also tested regular RAW. The manual states RAW files average 48MB and e-shutter buffer depth of 93 frames. With my black frame test I got 97 frames for a total of 4500MB while the manual states about 4425MB (93*47.6MB). Interestingly from the start of the sequence to the time the buffer fully cleared was about 10 seconds, 3-4 seconds faster than CRAW. But CRAW generated 138 frames which the camera had to process/compress.
Anyway, this would indicate that for regular RAW, write speed is at least 450MB/s, which is definitely faster than V90 SDXC. With the camera writing to both CFe and V90 SDXC, total shot count dropped to 86 images and took 17 seconds from first shot until fully cleared. This was 3940MB @ 17 seconds = ~230MB/s. 86 images is the maximum SDXC RAW burst stated in the manual. So for regular RAW, SDXC indeed hampers performance.
Interestingly, repeating with CRAW shooting to both cards, total shot count was still 138 and total time from first exposure until the buffer fully cleared was still around 14 seconds. I repeated with only the SDXC card and as one might expect, performance was the same: 138 frames and ~14 seconds to totally clear. And this confirms the manual, which states that CRAW buffer depth is the same for CFe and SDXC. And also confirms what I noticed in the field, that buffer performance in CRAW didn’t appear to be noticeably affected if shooting to both cards.
I repeated a couple of the tests with the older Angelbird CFe 2.0 card and there was no performance difference.
As you're coming from the R6II like I am, one performance advantage of the R5II is that it very quickly clears about 15 frames (in CRAW) right after the buffer totally fills. I was frustrated numerous times by the R6II because it would not free up any buffer space for ~5 seconds after totally filling it (in the heat of the moment, it always felt like an eternity), which caused me to miss shots, especially given that 40fps at high ISO, buffer depth was maybe only 2.5 seconds compared to 4.5 seconds with the R5II (though at 30 fps). The inability to fine tune frame rate with the R6II means that there's less ability to stretch out the buffer by slightly reducing frame rate, such as to 30 fps. Instead one has to drop all the way to 20.
I also repeated the CRAW test at ISO 100 but it really skewed the results because the CRAW black frame ended up being only ~3MB in size, the buffer could do ~250 before stuttering and generated only 895MB total storage consumption. It seemed like an unrealistic set of parameters that would not exist in most real world shooting situations.
The basic takeaways:
If shooting RAW at 30fps, you want to shoot to only CFe to maximize buffer capacity and buffer clearance.
If shooting CRAW at 30fps, shooting to both cards (SDXC V90) is not noticeably slower than shooting to only CFe.
p.1 #5 · Best CF card for canon R5 Mark ii for wildlife and bird Photography
rscheffler wrote:
I don't believe any CFe 4.0 card will restrict the R5II's max write speed capability, which appears to be well below that of 4.0 cards, which is a reason why you're hitting the buffer.
As for actual figures, AFAIK, nothing has been officially released by Canon and this was a question raised prior to the R5II's release (whether it operated at CFe 4.0 speed). One could approximate the camera's card write speed by shooting a burst until the buffer clears, time the duration from first to last shot, then divide the total storage requirement for all the images by the time it took to write out the buffer....Show more →
The R5 II does not support CFe 4.0, only CFe 2.0. However, CFe 4.0 cards fall back to CFe 2.0 mode in cameras or readers that don't support 4.0. There is no CFe 3.0 since the CompactFlash Association decided to align the CFe version with the PCIe version and jumped from 2.0 to 4.0.
p.1 #6 · Best CF card for canon R5 Mark ii for wildlife and bird Photography
rscheffler wrote:
The basic takeaways:
If shooting RAW at 30fps, you want to shoot to only CFe to maximize buffer capacity and buffer clearance.
If shooting CRAW at 30fps, shooting to both cards (SDXC V90) is not noticeably slower than shooting to only CFe.
I write RAW or CRAW to my CFe card and JPEG to my SD card, and assumed that since the JPEGs are so much smaller, writing them to the SD wouldn't slow things down. Does that make sense?
p.1 #7 · Best CF card for canon R5 Mark ii for wildlife and bird Photography
rscheffler wrote:
The basic takeaways:
If shooting RAW at 30fps, you want to shoot to only CFe to maximize buffer capacity and buffer clearance.
If shooting CRAW at 30fps, shooting to both cards (SDXC V90) is not noticeably slower than shooting to only CFe.
vbnut wrote:
I write RAW or CRAW to my CFe card and JPEG to my SD card, and assumed that since the JPEGs are so much smaller, writing them to the SD wouldn't slow things down. Does that make sense?
Maybe. What size jpegs? What we don't know is when the camera is writing to both slots, whether it writes to each independently, and if so, if it can maximize throughput to each one. More likely, it writes at the speed of the slowest slot.
From my quick testing above, if you're shooting CRAW, there is no noticeable speed penalty to writing to both slots, as long as the SD slot is a V90 card. If shooting regular RAW and jpeg to the se, then probably still a slowdown.
I have not tested your scenario but would be pretty easy for you to test by shooting just RAW to CFe, then shooting the same scene with RAW to slot 1 and jpeg to slot 2.
What is your reason for jpeg to slot 2? As a form of back up?
Personally I mostly shoot CRAW now and if I really, absolutely need immediate jpegs, I will extract the full-rez jpeg previews embedded in the RAW/CRAW files (with Photo Mechanic - not sure what other apps do this).
p.1 #9 · Best CF card for canon R5 Mark ii for wildlife and bird Photography
rscheffler wrote:
What is your reason for jpeg to slot 2? As a form of back up?
Partly inertia, as I've been doing that with previous Canon cameras. It's a combination of a (weak) backup and having JPEGs to use immediately if necessary, especially since I'm months behind in processing my RAWs.
p.1 #10 · Best CF card for canon R5 Mark ii for wildlife and bird Photography
rscheffler wrote:
Maybe. What size jpegs? What we don't know is when the camera is writing to both slots, whether it writes to each independently, and if so, if it can maximize throughput to each one. More likely, it writes at the speed of the slowest slot.
From my quick testing above, if you're shooting CRAW, there is no noticeable speed penalty to writing to both slots, as long as the SD slot is a V90 card. If shooting regular RAW and jpeg to the se, then probably still a slowdown.
I have not tested your scenario but would be pretty easy for you to test by shooting just RAW to CFe, then shooting the same scene with RAW to slot 1 and jpeg to slot 2.
What is your reason for jpeg to slot 2? As a form of back up?
Personally I mostly shoot CRAW now and if I really, absolutely need immediate jpegs, I will extract the full-rez jpeg previews embedded in the RAW/CRAW files (with Photo Mechanic - not sure what other apps do this).
p.1 #11 · Best CF card for canon R5 Mark ii for wildlife and bird Photography
Vksrik wrote:
I’ve been going through the Canon manual and checking specs from different memory card manufacturers, and I have a simple question: what are the actual read and write speed limits of the camera body, and which memory cards can truly take advantage of the camera’s full capability? I don’t want to end up buying an ocean when the real requirement is just a pool of water, and I’d really appreciate some real-world guidance. For reference, I’m currently using Delkin Power cards (Delkin Devices 512GB POWER 4.0 CFexpress Type B Memory Card offers burst read speeds up to 3650MB/s and burst write speeds up to 3240MB/s in addition to a sustained write speed of 820MB/s. ) , which I’m quite happy with overall, but I do occasionally hit the buffer limit when shooting C-RAW in H+. Thanks in advance!...Show more →
Typically any card that meets or exceeds the camera's specs will operate at essentially the same speed in the camera since it is the camera, not the card, that controls the speeds. Getting the very fastest card available isn't really necessary.
p.1 #12 · Best CF card for canon R5 Mark ii for wildlife and bird Photography
rscheffler wrote:
If shooting CRAW at 30fps, shooting to both cards (SDXC V90) is not noticeably slower than shooting to only CFe.
This is good info as I would not have guessed this, but I know from shooting RAW it slows down the camera. Are you 1000% sure there is no other hit to performance when writing CRAW to both cards, maybe other than burning a tiny bit of extra battery?
One important question on this that I recall running into issues in the past with older DSLR bodies - If your CFe is 2x than your SD card, say 512gb CFe vs 256gb SD, will the camera stop shooting when your SD card is full? You would think there would be an option to give you a "warning only" when your SD card is full, but I seem to remember an issue where it just stops shooting at that point, which is completely lame if still true. A nice little "warning only" option that gives you a heads up would be perfect to inform us the SD card has been filled, as most people's CFe cards are bigger than their SD cards.
p.1 #13 · Best CF card for canon R5 Mark ii for wildlife and bird Photography
rscheffler wrote:
If shooting CRAW at 30fps, shooting to both cards (SDXC V90) is not noticeably slower than shooting to only CFe.
artsupreme wrote:
This is good info as I would not have guessed this, but I know from shooting RAW it slows down the camera. Are you 1000% sure there is no other hit to performance when writing CRAW to both cards, maybe other than burning a tiny bit of extra battery?
I didn't do multiple tests with rigorous attention to timing but it seemed like writing CRAW to both slots was maybe one second slower than just to CFe. But it could also have been only a half-second. Or no difference. I haven't noticed any other obvious performance hit. With regular RAW, yes, writing to both slots reduces the total number of shots that can be buffered compared to shooting to only CFe. The slower write speed of V90 SDXC becomes a factor.
The interesting thing here was that shooting RAW to only CFe cleared the buffer 3-4 seconds faster (in my tests) than CRAW to only CFe (or to both slots, since the time was about the same). Granted, RAW resulted in ~97 files vs ~138 CRAW, so there were fewer files. But the total amount written, in terms of storage consumption, was about 40% more with RAW than CRAW. And it wrote more MB/s than CRAW. It was faster than the V90 max write speed, hence the reason writing to both cards slows it down. But when it's CRAW, it appears the camera's write speed whether to CFe only or to SD, is at around the V90 threshold. That it's not writing as fast as RAW suggests something related to processing out the files during capture slows it down and not the V90 write speed limit.
artsupreme wrote:
One important question on this that I recall running into issues in the past with older DSLR bodies - If your CFe is 2x than your SD card, say 512gb CFe vs 256gb SD, will the camera stop shooting when your SD card is full? You would think there would be an option to give you a "warning only" when your SD card is full, but I seem to remember an issue where it just stops shooting at that point, which is completely lame if still true. A nice little "warning only" option that gives you a heads up would be perfect to inform us the SD card has been filled, as most people's CFe cards are bigger than their SD cards....Show more →
I haven't had this happen to me yet with my mirrorless cameras (I try to keep on top of it), but suspect the camera will just stop. I guess some things never change with Canon, even after ~20+ years. I think it's one of the downsides of shooting high capacity cards. You get used to the 'endless' storage and then forget to keep on top of it. Not that I'm complaining about having 512 and 256GB cards because I certainly remember having only 512 and 256MB cards!
AT LEAST the cameras now don't stop shooting when you hit file number 9999! That was a pain in the butt with the original 1D. The first couple times it was like ^%$# is the camera suddenly not working?
I'd love to have the option for five digit sequential numbering rather than four, but I think the XXXX1234 file format might be a universal standard (stuck in 80s or 90s DOS computing limitations).
I haven't noticed any other obvious performance hit. With regular RAW, yes, writing to both slots reduces the total number of shots that can be buffered compared to shooting to only CFe. The slower write speed of V90 SDXC becomes a factor.