CF as backup or SD as backup?

Got a 5d3. In this day in age of advancing memory card tech, it used to be SD cards werent as reliable as CFs. But now I think the game is level right? Speed aside, what would you guys choose to run in your cameras? CF as the main card and SD as backup or visa versa SD as main and CF as backup.

Currently Im thinking getting 1x 256gb SD card as a backup that always stays in the camera, and then running multiple 32gb cf cards as mains. In this scenario the SD card would get more writes in a shorter lifespan but is cheaper to replace

SD cards are generally cheaper. I dont care really about speed. The cards out these days are good enough for me in that department. Way better than what they used to be.

What are you shooting?

Are you getting paid for it?

Please explain the relevancy to the topic of those questions? Cost it seems like it's based on speed of card. Even the 50mb/sec SanDisk ultras would be good enough for me. So technically speaking I'd be fine with the cheapest model.

To me, "back up" means back up. Speed has nothing to do with the question, and you even said, "speed aside".

Please explain what back up means to you.

Back to the OP's question, I would ask, what will be the method of transfer of images in the camera to computer. If one uses a direct cable to PC then the reliability situation is different than a method involving the removal of the card and using a card reader. CF card removal exercises the pins in the camera body. IMO the SD "connection" is less subject to issues caused by constant insertion and removal.

And I realize there will be plenty that chime in they have had SD cards fail, but I haven't.

Left Handed Brisket wrote in post #18168175
To me, "back up" means back up. Speed has nothing to do with the question, and you even said, "speed aside".

Please explain what back up means to you.

Still dont get the question. Backup is reliability. Correct, speed and price has nothing to do with the question...well sort of price as SD cards are cheaper.

John from PA wrote in post #18168260
Back to the OP's question, I would ask, what will be the method of transfer of images in the camera to computer. If one uses a direct cable to PC then the reliability situation is different than a method involving the removal of the card and using a card reader. CF card removal exercises the pins in the camera body. IMO opinion the SD "connection" is more less subject to issues caused by constant insertion and removal.

And I realize there will be plenty that chime in they have had SD cards fail, but I haven't.

cards out for transfer. Im not worried about pins. Never had an issue with pins in my tens of thousands of times i inserted or removed my cf cards. I suppose sd cards will be more reliable in that area.

kaitanium wrote in post #18168153
Got a 5d3. In this day in age of advancing memory card tech, it used to be SD cards werent as reliable as CFs. But now I think the game is level right? Speed aside, what would you guys choose to run in your cameras? CF as the main card and SD as backup or visa versa SD as main and CF as backup.

Currently Im thinking getting 1x 256gb SD card as a backup that always stays in the camera, and then running multiple 32gb cf cards as mains. In this scenario the SD card would get more writes in a shorter lifespan but is cheaper to replace

SD cards are generally cheaper. I dont care really about speed. The cards out these days are good enough for me in that department. Way better than what they used to be.

You don't care about speed so I assume that you know the SD BUS on the 5D3 is significantly slower than the CF BUS. In other words, if you are writing the same size files to both cards it is going to take a lot longer for the buffer to flush to the SD card and consequently it will cause a bottleneck. In speed critical situations I always used CF only in the 5D3 for this reason. If you mean that you don't care about speed because both formats meet or exceed your requirements then it doesn't really matter which you use for backup. Your logic about SD cards seems sound but I don't think there is a big difference either way.

kaitanium wrote in post #18168153
Got a 5d3. In this day in age of advancing memory card tech, it used to be SD cards werent as reliable as CFs. But now I think the game is level right? ... The cards out these days are good enough for me in that department. Way better than what they used to be.

1. Internally, a CF card has always been a silicon chip encased in an outside package, with 24 microwires connecting contact 'pads' on the chip to the tiny female contacts of the CF.
   
2. Internally, an SD card has always been a silicon chip encased in an outside package, with 9 microwires connecting contact 'pads' on the chip to the large male contacts of the SD.
   

As a somewhat side note-I did have an issue with bent pins and a CF card . If I recall correctly, it was $370. Repair. But I still use CF primary in my 7Dll. FWIW

nqjudo wrote in post #18168394
If you mean that you don't care about speed because both formats meet or exceed your requirements then it doesn't really matter which you use for backup.

yup this is it. Im currently using sandisk 32gb CFs extremes at 60mb/s and its been wonderful over the 2 years ive had them. I do have faster ones at 120 that i use in conjunction but really do i notice a night and day difference in what i do (weddings)? Not really.


If reliability is the same, then for me, the SD card as mains may edge out better as it has 3 factors 1. non bendable pins (nice to have i guess, though I never experienced bent pins) 2. cheaper 3. built in sd card readers on my comps.


Thanks for the info all.

Wilt wrote in post #18168401

1. Internally, a CF card has always been a silicon chip encased in an outside package, with 24 microwires connecting contact 'pads' on the chip to the tiny female contacts of the CF.
   
2. Internally, an SD card has always been a silicon chip encased in an outside package, with 9 microwires connecting contact 'pads' on the chip to the large male contacts of the SD.
   

Not so accurate on SD these days and back about at least 5 years. SD and uSD today use something called SIP package. There is no wire of any kind. It is a PCB embedded into some fiber/epoxy substrate. the plastic over of the SD is just for maintaining the form factor. That is how SD card are being advertised as water proof/dust/ice proof.

CF on the other hand, it is still expose PCB with SMT component, wire and connectors. So it is not subject to environmental effect. So in term of physical reliability, SD > CF. But both are very good to begin with, you shouldn't have any issues

In terms of product level reliability, no comparison here. CF >> SD. The reason is CF is a niche product these days. Volume is extreme small while profit is high. Manufacture didn't bother to go into cost reduction on CF product. CF these day still are on 19nm MLC or SLC. SD however, it is a volume product. Low cost is important. Most if not all SD today is in 16nm TLC. So from flash memory stand point, CF uses much higher quality flash inside.

Having the above said, for 5D3, CF as primary, SD as backup.

Thx for bringing me up to date with the internal technology of CF vs. SD packing, and fundamental quality level of limited quantity vs. volume economy products.

good stuff thats probably the answer i was shooting for! thanks for the info! This means I still rather have a more reliable CF as backup. Except hi-cap CFs are pricey!

and if someone is curious about speeds using a SD, looks like its decent (at least for me): http://blog.photoshelt​er.com …or-the-canon-5d-mark-iii/

again for me, im not too worried.

Compact flash as main card.
SD as "back up"

These days I end to shoot RAW to CF and jpeg to SD, but on occasion I write RAW to both as the in camera "RAID 1 Mirror" in case a car dfails.


I posted just recently on my own experience of CF reliability vs. SD,. I found that SD had something like a 30X higher failure rate than CF (again, only one mans' data)