How Does SD Card Impact CFexpress Performance on X-H2s/X-H2?

For my X-T3, I use two identical SDXC memory cards: SanDisk 128GB Extreme PRO UHS-II. For my X-H2s, I am using a ProGrade Digital 325GB CFexpress card in the first slot.

I want to make use of the SD slot in the X-H2s as well, but I am not sure how using the SD slot will impact performance when using it in conjunction with the CFexpress card. Depending on the event, I might use the second card for backup or jpeg only. Since my CFexpress card is 325GB, I don't expect I will need to use the SD slot as overflow.

Has anyone evaluated the performance impact of the SD slot when used for backup or jpeg only writing vs. using just CFexpress? Are there known best practices for maximizing performance when both slots are used?

I assume that - in case of a backup/duplicate, the slowest card will dictate the overall speed. So buffer capacity etc will be greatly reduced using a CF with SD backup (or vice versa). A jpeg backup instead of Raw will probably be quicker.

Disclaimer: I do not own an XH(s) so the above is a pure assumption.

Sjeupie wrote:

I assume that - in case of a backup/duplicate, the slowest card will dictate the overall speed. So buffer capacity etc will be greatly reduced using a CF with SD backup (or vice versa). A jpeg backup instead of Raw will probably be quicker.

Disclaimer: I do not own an XH(s) so the above is a pure assumption.

So you just made stuff up?

From the manual:

Night Pixel wrote:

Sjeupie wrote:

I assume that - in case of a backup/duplicate, the slowest card will dictate the overall speed. So buffer capacity etc will be greatly reduced using a CF with SD backup (or vice versa). A jpeg backup instead of Raw will probably be quicker.

Disclaimer: I do not own an XH(s) so the above is a pure assumption.

So you just made stuff up?

I researched this topic myself because I had the same question as the OP. And the above was the outcome of that research. I have not been able to verify it though, which is why I mention I assumed it rather than stating is as a fact.

But thanks for your negative reply and the screenshot of the manual that does not answer the OP's question. Just because its not 'made up' does not make it useful.

I've used fast SD cards as overflow and experience a significant reduction is buffer and flush speed.  It is quite noticeable even using short bursts.  I have not done backup yet the SD card will clearly become the limitation.

Try the setup you are considering and see if it will meet your needs.

Morris

Night Pixel wrote:

Sjeupie wrote:

I assume that - in case of a backup/duplicate, the slowest card will dictate the overall speed. So buffer capacity etc will be greatly reduced using a CF with SD backup (or vice versa). A jpeg backup instead of Raw will probably be quicker.

Disclaimer: I do not own an XH(s) so the above is a pure assumption.

So you just made stuff up?

From the manual:

Next time, try just presenting the data rather than including a derisive (and unnecessary) comment like this.  I think he made it patently clear that this was an assumption.

Night Pixel wrote:

Sjeupie wrote:

I assume that - in case of a backup/duplicate, the slowest card will dictate the overall speed. So buffer capacity etc will be greatly reduced using a CF with SD backup (or vice versa). A jpeg backup instead of Raw will probably be quicker.

Disclaimer: I do not own an XH(s) so the above is a pure assumption.

So you just made stuff up?

From the manual:

I don't think you meant it that way, but your response sounds kind of rude.

I own the X-H2S and I understand it the same as Sjeupie. Any speed bottlenecks are dictated by the slower of the two cards. In this case, the CFexpress card is almost always considerably faster than the SD card. So, if you use both cards as a "mirror" backup (duplicate backup), SD cards with faster write speeds should theoretically help with the camera's speed.

When researching SD cards, I found the following website to be useful as a reference.

https://havecamerawilltravel.com/fastest-sd-cards/

I ended up purchasing the Kingston Canvas React Plus V90 UHS-II when it was on sale.

When I shoot burst, I don't usually max it out at 40fps, so I haven't really put the card through its paces, but the SD card seems to be working great.

I hope this helps.

From the responses, it seems that the best approach is to avoid using an SD card for anything more than jpeg files when high speed burst is being used, although it might be best to use the CFexpress card for everything when capturing at high speed.

I will try exclusively using the CFexpress card for events when I am mainly capturing bursts and only use an SD card for backup or jpeg files for slower paced photography.

Thank you for your feedback!

sshapiro wrote:

For my X-T3, I use two identical SDXC memory cards: SanDisk 128GB Extreme PRO UHS-II. For my X-H2s, I am using a ProGrade Digital 325GB CFexpress card in the first slot.

I want to make use of the SD slot in the X-H2s as well, but I am not sure how using the SD slot will impact performance when using it in conjunction with the CFexpress card. Depending on the event, I might use the second card for backup or jpeg only. Since my CFexpress card is 325GB, I don't expect I will need to use the SD slot as overflow.

Has anyone evaluated the performance impact of the SD slot when used for backup or jpeg only writing vs. using just CFexpress? Are there known best practices for maximizing performance when both slots are used?

You are restricted by the slower card BUT you will find you can still shoot long bursts in backup mode - the X-H2S has a large buffer - it will just take a long time for the slower card to clear.

For example you could shoot continuous high bursts of as much as 100 lossless compressed images provided you wait between bursts.

Jerry-astro wrote:

Night Pixel wrote:

Sjeupie wrote:

I assume that - in case of a backup/duplicate, the slowest card will dictate the overall speed. So buffer capacity etc will be greatly reduced using a CF with SD backup (or vice versa). A jpeg backup instead of Raw will probably be quicker.

Disclaimer: I do not own an XH(s) so the above is a pure assumption.

So you just made stuff up?

From the manual:

Next time, try just presenting the data rather than including a derisive (and unnecessary) comment like this. I think he made it patently clear that this was an assumption.

Jerry, I understand your perspective. My comment was intended to convey the poster had nothing to answer the OP's question. The comment was admittedly based on assumptions and disclaimers. My response was "so what is the point?" I suppose I could have been more polite and for that I am sorry.

Night Pixel wrote:

Jerry-astro wrote:

Night Pixel wrote:

Sjeupie wrote:

I assume that - in case of a backup/duplicate, the slowest card will dictate the overall speed. So buffer capacity etc will be greatly reduced using a CF with SD backup (or vice versa). A jpeg backup instead of Raw will probably be quicker.

Disclaimer: I do not own an XH(s) so the above is a pure assumption.

So you just made stuff up?

From the manual:

Next time, try just presenting the data rather than including a derisive (and unnecessary) comment like this. I think he made it patently clear that this was an assumption.

Jerry, I understand your perspective. My comment was intended to convey the poster had nothing to answer the OP's question. The comment was admittedly based on assumptions and disclaimers. My response was "so what is the point?" I suppose I could have been more polite and for that I am sorry.

Kudos to you for your explanation and apology.

I have the X-H2 and have tried using a fast V90 SD card and have a CF Express card. Basically the buffer is the buffer, there is no difference in the number of RAW photos you can shoot, however the difference is clearing the buffer. The CF Express card takes say 9 seconds, the V90 card takes like 30 seconds!

If you shoot a lot at 15 fps then invest in a CF Express card, it will be worth it. I used the Angelbird AV PRO SE 512GB 1785 MB/S  and it works fine and is only £160.