SD Card To Mirror This 32GB CF Card?

Hi all,

I have a Canon 5DmkIII.

I currently have this Compact Flash card which I use, along with an SD card with lower spec/speed writing.

I want to use both as I had my very first card failure a few weeks ago, so want to take advantage of the dual card slots.

I don't take a lot of fast frame action, but i'm aware that if I do, then the write speed is only as good as the slowest card in the camera.

So, i've been trying to find an SD card to match this CF card, but struggling to get anywhere near it.

I was wondering if anyone has come across an SD with the same spec or very close to my CF card, or am I really worry about nothing and the speed writing difference between say a 160mb/s and a 90mb/s is actually negligible when actually put to the test

Thanks all

tuttifrutti wrote in post #18742819
Hi all,

I have a Canon 5DmkIII.

I currently have this Compact Flash card which I use, along with an SD card with lower spec/speed writing.

I want to use both as I had my very first card failure a few weeks ago, so want to take advantage of the dual card slots.

I don't take a lot of fast frame action, but i'm aware that if I do, then the write speed is only as good as the slowest card in the camera.

So, i've been trying to find an SD card to match this CF card, but struggling to get anywhere near it.

I was wondering if anyone has come across an SD with the same spec or very close to my CF card, or am I really worry about nothing and the speed writing difference between say a 160mb/s and a 90mb/s is actually negligible when actually put to the test

Thanks all

Hosted photo: posted by tuttifrutti in
./showthread.php?p=187​42819&i=i195982963
forum: Data Storage, Memory Cards & Backup

Lots of choices...see https://havecamerawill​travel.com …grapher/fastest​-sd-cards/.

Personally I would go with the Sandisk option. Here in the States it is likely to be found at Best Buy which is reliable becuase they purchase memory cards direct from the importer. SD cards are often counterfeited, so in the UK try to deal with a large company to source what you decided on. Do not buy on eBay and use caution with Amazon.

The current version is 300 MB/s and pricy (US$100 list). After you buy this you will need to upgrade your CF card.

[Edit] I see Jessop's has it on sale... https://www.jessops.co​m …uhs-ii-memory-card-133887

Don't bother with high speed SD card for your 5D3.
You already aware that the SD slot is capped at 133x speed.

Just get the cheapest 32gb SD card & use it for a backup for your CF card via the Copy Image / Copy Folder menu inside the camera.
That's how I did it with my old 5D3s.

virsago_mk2 wrote in post #18743547
Don't bother with high speed SD card for your 5D3.
You already aware that the SD slot is capped at 133x speed.

Just get the cheapest 32gb SD card & use it for a backup for your CF card via the Copy Image / Copy Folder menu inside the camera.
That's how I did it with my old 5D3s.

Good point, but at least the OP now knows there is an SD card to match the CF card, but the camera just can't utilize it.

Thanks very much to you both for your replies.

TBH I wasn't aware that my camera was capped at 133x.

With regards to your comment Virago, about using the CF card as copy image etc, if I were using this way to 'back up' my CF images to my SD as i'm shooting, would I not still need the fastest SD card I can get, up to 133x?

Afaik 133x is the lowest speed for the current budget SD card. Don't think you can find any other brand new SD card that is slower than that nowadays. Unless you manage to scourge a used micro sd from a Sunday market that is made from 2009 or something.

Just make sure your Record Function is set at Automatic or Auto Switch Card, with CF card selected. That way it will ensure that your camera's writing speed & buffer isn't bottlenecked by the SD card slot.

More reading here
https://petapixel.com …-if-you-care-about-speed/

However if later on you're planning to upgrade to a camera that support UHS SD card, then by all means get the fastest SD card you can afford.
Moreover you can still utilise the high read speed of the SD card when you transfer the data to the computer.
It's just that 5D3 has a very slow SD card slot & generally not worth using it, better to just use CF card alone.

Thanks very much for the concise reply. I'll have a read on the link you left, later.

I think up until 3 weeks ago when I had my first ever CF card failure and lost a lot of pics, I would happily have continued just using the CF slot.

However, that's card failure really made me think about losing images. I'm off to Canada next year for 2 weeks - I cannot imagine how heartbreaking it would be to lose a lot of those images, so I thought it best to utilise the dual slot - that's what it's there for right

Where are you visiting in Canada?

Hi Jethro. We are starting off in Calgary and spending 2 weeks making our way to Vancouver. Got plenty of thinks on our 'to do' list, my one being Sturgeon fishing on the Frazer river

tuttifrutti wrote in post #18746729
Hi Jethro. We are starting off in Calgary and spending 2 weeks making our way to Vancouver. Got plenty of thinks on our 'to do' list, my one being Sturgeon fishing on the Frazer river

If things are not yet cast in stone, think of the 2019 Calgary Stampede. It runs in 2019 from July 5 to July 15th. Awesome event for a few nights.

We stayed at a place called Cindy's Bed and Breakfast in Dewinton, Alberta, maybe De Winton?

Unfortunately it doesn't seem to exist anymore as a B&B, but Dewinton was a good area to stay, especially if you were going to the Stampede. It was a short distance to a train station that dropped you off right at the Stampede grounds.

Shooting with two 5D Mark III's, I always have a CF and an SD card inserted. SanDisk Extreme both with the same GB amount. I always shoot RAW and "Record Seperately" to both cards. Same image on both the CF and the SD. When traveling abroad my SD acts as a back up.
The only time I do not have both cards inserted is when shooting sports where long bursts are necessary. That is where the card you have above, the SanDisk Extreme PRO comes in to play.
Yes we all wish the Mark III was not hampered in the situation above.

this is an UHS-II card, I doubt any canon cameras have that interface. 5DIII doesn't even support full UHS-I interface speed. So I think save some money and get an UHS-I card is better choice

Rob Galbraith used to test different memory cards in different digital cameras and publish the results; but then he stopped. Fortunately others have stepped up to fill the tests and reports previously, like these tests https://www.cameramemo​ryspeed.com …iv/sd-cf-card-speed-test/
Unfortunately the 5DIII is not tested by this tester.

In it, the fastest SD card was only 70% of the fastest CF card (112 MB/sec) in write speed tests in a Canon 5DIV...and Canon has not been known for its ability to maximize performance with fast SD. In some other tests, SD has been measured at about 250 for sequential writes, and 160 for random writes.

So (for the 5DIV) you would need to deliberately choose one of the two SLOWER CF cards in the sample population, at about 78MB/sec, in order for the SD to 'keep up' with the CF card!