mikegreenwald Loc: Illinois

I've been troubled by the extremely long times required to transfer large files from memory cards to the computer. The read speeds of my cards are 140MB/s or slower. In searching the internet, I find cards available (high prices!) with read speeds up to 560 MB/s, write speeds slower.
Has anyone significant experience with these high speed cards - reliability, bottlenecks other than the cards? etc? Do the speeds match the advertised rates?

DaveO Loc: Northeast CT

I would not be blaming the cards so quickly. Are you downloading through the camera or an appropriate card reader? Also you're computer may share in the blame. I'm betting that faster cards may not solve your dissatisfaction.

Dngallagher Loc: Wilmington De.

While the read/write speeds of course are important, you might want to look at the connection - how are you transferring? Card reader? USB 1.1, 2.0 or 3.0? Direct camera to Computer via USB cable? Find your bottleneck first, then adjust to increase your speed.

Basically a super ultra fast SD card does you absolutely no good if your USB connected reader is running at USB 1.1 or 2.0

https://en.wikipedia.org/wiki/USB

rjaywallace Loc: Wisconsin

Depending on the size and nature of the file (RAW?) you are trying to transfer, you want to use cards with the highest Write speed. The Read speed affects how fast your camera records the file and is ready for the next shot. As an alternative consider using the cable that should have come with your camera to transfer files directly from the camera to your computer. If you place the cards in a slot on the computer, you might consider buying one of those card reader devices which transfer files to your computer, generally using a USB cable connection.

Dngallagher Loc: Wilmington De.

Don't you have that backwards? READ speed is how fast the file on the card can be read WRITE speed determines how fast the camera can write the file to the card. For the complete speed both the card and camera hardware need to be known.

Using the camera cable will lock you to the speed of the slowest part - possibly the camera USB speed. A card reader is almost always the fastest method of transferring images, assuming USB 3.0 for the computer USB connection and USB 3.0 for the card reader.

This site has real world speed tests, ratings of cards based on camera speeds and costs - very handy.

http://www.cameramemoryspeed.com/

DaveO Loc: Northeast CT

Keep in mind that a particular camera can only write so fast,so faster cards would be a waste for some in that aspect. I believe the 160mbs read speed is being hindered and agree with a bottleneck.

John_F Loc: Minneapolis, MN

This reply caused me to look at that little camera manual to discover its 'write file' speed is. Answer - no specification. Thus, writing to a card is at the mercy of the card. It a Sony a6300. Sigh.

DaveO Loc: Northeast CT

You can put a jet engine in your car and it still can't fly. The write speed is dependent upon the attributes of the camera if the card can handle it. If the card has higher capabilities than the camera,it will not be used. I'm not going to research cameras for the write speed capabilities,but I believe many can not fully utilize what we purchase. I'm sure there are members who can be specific.

Dngallagher Loc: Wilmington De.

The A6300 is a UHS-I speed camera, so it has a bus that should support up to 104 mbs write speed.... BUT, apparently Sony limited the camera write speed for some reason - see further down.
Camera manuals may not list everything, so look around.

http://www.cameramemoryspeed.com/sony-a6300/fastest-sd-cards/

And for an explanation of UHS- speeds....

http://panasonic.net/avc/sdcard/industrial_sd/performance.html

If you read down the page, the documents show that while the A6300 has a UHS-I bus, it is write speed limited by design. so even the fastest cards are down to mediocre write speeds...

"Sony A6300 Test Analysis

Like its predecessor, A6300 is limited in write speed. It measured up to 35.5 MB/s average write speed during continuous shooting of RAW images. The previous A6000 reached 35.9MB/s maximum write speed. Although write speed is limited, the A6300 has a decent buffer which makes the camera feel responsive during high frame rate bursts shorter than seven seconds regardless of the memory card used. Because the camera is write speed limited the difference between memory cards in this camera is not as pronounced as other cameras.

The buffer allowed continuous shooting at full frame rate for 21-25 images in RAW+JPEG mode, which is similar to the previous model. However in RAW mode the A6300 improved by allowing up to 28 shots, while the previous model only captured 24 at full frame rate. The range for JPEG mode was 33-50 shots at full frame rate before it slowed, which is a slightly larger range than the 46-49 shots of the A6000. The range is largely a result of the write speed, with fast cards able to clear the buffer faster during shooting which allows extra shots.

The performance of memory cards is most apparent after the buffer has reached capacity. In RAW+JPEG mode the frame with the buffer full was 1 fps using the fastest card and 0.3 fps with the slowest card. In RAW mode the range was 1.5 fps to 0.6 fps. The frame rate with the buffer full in JPEG mode was as high as 1.7 fps and as low as 0.9 fps. This an improvement over the A6000 which was about 1.2 fps for nearly all cards. The the number of JPEG images captured in 30 seconds improved to 118 over the 79 of the previous model with the fastest cards.

While the A6300 supports UHS-I it does not support the fastest SDR104 mode (104 MB/s) which requires a high bus speed. The A6300 does not have the UHS-II interface, but UHS-II cards can be used because the cards revert to UHS-I mode using the standard card interface. Using a UHS-II card offers no speed benefit over UHS-I cards in the A6300, but UHS-II cards will allow faster image downloads when used in a UHS-II

Unfortunately, it seems that the A6300 looks a bit slow, even though it has a UHS-I bus."

I guess sort of like a V-8 engine, but a 1 bbl carb to save on gas used.

mikegreenwald Loc: Illinois

Card reader is 3.0.

mikegreenwald Loc: Illinois

Camera is a 5D4, but because I use a card reader, that has nothing to do with the speed of downloads to the Mac Pro (1915) computer.
Apparently I have the read/write speeds reversed, but the faster cards are generally faster on both sides, so the problem is not solved.
My original question is still valid: Does anyone have experience with the very high speed cards, and if so, does it make a material difference?

jethro779 Loc: Tucson, AZ

Read this article. It breaks down the read & write on this camera. It says the average write speed is 112 mb/s max on the cards tested.

http://www.cameramemoryspeed.com/canon-5d-mark-iv/sd-cf-card-speed-test/

mikegreenwald Loc: Illinois

These tests are primarily for in-camera transfer speeds. They offer some help in the recommendation for the demonstrated download speed of UHS II cardreaders.
None of the tests mention the 560 MB/s claimed for a few cards, and that's what I'd like to learn, in actual field use.

DaveO Loc: Northeast CT

It is quite apparent that you will not be satisfied until you buy the fastest card available. Do it and get back to us with your results,or keep hoping that you get the answers you seek about a faster card solving your issue. Save some time and order it today and be sure to order the UHS-11 if the possible gain is worth it to you. Thank you,

DaveO Loc: Northeast CT

You must not have read the whole link,here's the end when using a SSD: Downloading images from the Canon 5D Mark IV:

The Canon 5D IV has an integrated USB 3.0 port that allows images to be transferred directly to a computer. To test this transfer method Secure Digital and CompactFlash cards with 7GB of RAW images were used. The camera was connected using a USB 3.0 cable and images were transferred to a fast SSD drive in a computer. The Lexar 1066x 32GB CompactFlash card completed the transfer in 108.5 seconds and averaged 61.2 MB/s. The SanDisk Extreme 95MB/s UHS-I U3 32GB SD card took 185.5 seconds at an average transfer rate of 35.8 MB/s. The CompactFlash transfer rate was just slightly above the 53.4 MB/s speed measured in the 5Ds, however the SD card transfer rate was well below the 65.4 MB/s of the 5Ds.

The preferred method to transfer images when speed is important is to use an external memory card reader. Transfers of RAW images from SD cards using a USB 3.0 card reader typically average 90 MB/s with UHS-I cards and 250 MB/s for UHS-II cards. CompactFlash cards can reach 140MB/s copying actual RAW files using a USB 3.0 card reader. Several card reader tests with various memory cards can be found in the Card Reader Reviews.