7D2 with two cards

Does the 7D2 burst rate slow down if recording to two cards? I use 1066X CF cards now but would like to also record to a SD card cometimes.

I use both sandisk extreme pro CF and SD cards and find negligible lag.
I once use I believe an ultra SD card and the lag is quite significant.

This might help

7DII memory card test

SD cards are inherently slower, for the most part, but the lag is after the buffer is filled. So for bursts, you may be ok, depending.

send the raw to the cf and the jpg to the sd and you may not see much lag with fast cards.

The 7D2 has a UHS-I SD bus (104 MB/s). I've got a Lexar SDXC II (150 MB/s) card which takes advantage of the fullest theoretical speed of SD on the 7D2. It's still a rather expensive card, but I have noticed it keeps up pretty well with CF cards for bursts.

I used to write to both cards during sports with the 7D2 and didn't see too much an impact. Since then, I now have the sd slot reserved for the wifi capability so that I can control/access remotely like my 5D4.

ksbal wrote in post #18404118
This might help

7DII memory card test

SD cards are inherently slower, for the most part, but the lag is after the buffer is filled. So for bursts, you may be ok, depending.

send the raw to the cf and the jpg to the sd and you may not see much lag with fast cards.

Very interesting Thank you. SD cards do appear to be slower in general.

KatManDEW wrote in post #18405608
Very interesting Thank you. SD cards do appear to be slower in general.

Yeah, in all the tests that I have seen to measure memory card speed, when a dSLR has both CF and SD slots, the fastest CF card is ALWAYS faster than the fastest SD card...in a speed ranked list of products, the best SD is always about half way down the list!

For now, but manufacturers have stopped developing faster CF standards in favor of new CFast or XQD formats. CF is not going to exceed UDMA 7 speeds: the fastest being 165 MB/s read 155 MB/s write. The latest UHS-II SD cards now are at 300 MB/s read and 260 MB/s write. If course the 7D2 doesn't support the fastest SD cards...in fact no Canon camera does. But other brands do.

Cameras with UHS-II support

davesrose wrote in post #18406192
For now, but manufacturers have stopped developing faster CF standards in favor of new CFast or XQD formats. CF is not going to exceed UDMA 7 speeds: the fastest being 165 MB/s read 155 MB/s write. The latest UHS-II SD cards now are at 300 MB/s read and 260 MB/s write. If course the 7D2 doesn't support the fastest SD cards...in fact no Canon camera does. But other brands do.

Cameras with UHS-II support

and then there is the question on the table about adoption of CFast vs. going to CFExpress, which is over 3X the speed of the fastest SD (6.0) UHS-III even in its slowest manifestation of CFExpress v1 with 2 lanes, and if/when it will appear in cameras.

Yep, so in the short run, the memory card battles are with SD/UHS-III, CFast 2.0, and XQD 2.0....with CFexpress nipping after that. I think for mirrorless and "consumer" DSLR cameras, SD formats will continue to be the norm because of the size/convenience factor.

davesrose wrote in post #18406208
Yep, so in the short run, the memory card battles are with SD/UHS-III, CFast 2.0, and XQD 2.0....with CFexpress nipping after that. I think for mirrorless and "consumer" DSLR cameras, SD formats will continue to be the norm because of the size/convenience factor.

CFExpress uses XQD form factor at 38.5 × 29.8 × 3.8 mm, while CF card is about 43 x 37 x 3.3 mm, so I certainly agree about SD being the format of choice in mirrorless designs.

Fantastic information! I have not kept up with memory card progress, and this helps my education!

Wilt wrote in post #18406114
Yeah, in all the tests that I have seen to measure memory card speed, when a dSLR has both CF and SD slots, the fastest CF card is ALWAYS faster than the fastest SD card...in a speed ranked list of products, the best SD is always about half way down the list!

Since I'm using Canon DSLR's, this is what effects me, for now.