oldtool2 Loc: South Jersey

This is the problem when trying to figure out what card speed to purchase. Very few, if any, manufactures make this information public.

I use a card reader to download my photos. My reader uses a class 3 usb port so I buy cards for that transfer speed. I am sure that the card will write faster to my computer than my camera will unload my buffer but this way I am sure I am taking full advantage of my cameras buffer write speed.

It might be costing me a few extra bucks but I have never had a problem by doing it this way.

Jim D

plewislambert

It isn't like driving a Ferrari at 45. That might be a lot of fun on a winding road. Using an SD card is not an emotional experience (until it fails!)

Having a fast card that reads and writes at high speed doesn't seem to have disadvantages. I bought a class 10 90mbs (what?) and my camera seems to empty a full buffer quicker than with the earlier slower card but not much. My Lenovo laptop seems to read the new card's 18mb Raw images quite quickly but it didn't seem slow before. Net benefit not a lot.
Philip

SharpShooter Loc: NorCal

Watching fotos download is like watching paint dry.
I always start a download and have dinner. When I return, theyre all done. Who cares how slow it is.
If you gotta have super fast udma's, go ahead, get'em, it's only money.
Not to mention good armchair fodder.

singleviking Loc: Lake Sebu Eco Park, Philippines

Jim,
Just to clarify, although USB 3.0 ports have a max transfer rate, it is not categorized in the same way as an SD cards or a memory module's read/write speeds. USB busses are made in 3 formats but all slower devices will function properly on the USB3.0 bus. This dtat speed is determined by your computer's MOBO and bus controller and not the memory media. In other words, you do not buy a CLASS 3 SD card and expect it to run at USB3.0 data transfer speeds, nor can you buy a USB3.0 card reader and expect that your SDHC cards will transfer data at that bus speed when the reader is plugged into a USB2.0 port. This speed is limited by where that data is being transferred to (ie. HDD or temp RAM storage) since the files will go into temp space while it is being processed and can only be written to the directed media storage at that storage device's data rate.

Pepsiman Loc: New York City

Now tell me! How fast a computer can copy your images? Is the computer faster than the fastest memory card? How fast are all the cameras?

You spend a lot of time editing but you must have a fast card... Now tell me (time wise) how long would a slow card download compared to a fast card? How much time will you save with a fast card?

singleviking Loc: Lake Sebu Eco Park, Philippines

Once you start the editing process, your photo files data should already be in your computer's HDD. Although the USB3.0 bus speed is approximately 6 Meg/sec., this rate can be significantly slowed down by your other storage devices like the HDD write speed, RAM amount and speed, bus controller's speed and the CPU speed and type. The actual
time saved in completely downloading a 4 Gig SD card with a USB2.0 versus USB3.0 Port and reader if this data was continually streaming, is actually less than a few seconds at best, but this is not how data is transferred. It is broken up, halted and waits for other devices to complete their function before resuming data transfer while post processing or transferring photo files. There is also the conversion of files into other formats used by PP programs.

The real reason for fast SD cards is to allow the camera's buffer to unload so the DSP can process the next photo's digital data. When your buffer's data transfer to the storage device, is halted your camera will not be able to take the next photo. This is demonstrated best when you shoot continuous frame or burst mode at the camera's max speed. If the buffer can't empty quick enough, the camera halts and stops till there is room in the buffer for the next frame's data.

Pepsiman Loc: New York City

THANK YOU! I learned something about the buffer. :thumbup: :thumbup: :thumbup: :thumbup:

planepics Loc: St. Louis burbs, but originally Chicago burbs

I found this chart on a website about my camera specs, among other data: (chart didn't copy correctly))

Very good to below average speed for a consumer digital SLR.

Buffer clearing time
5 seconds *
after 18 L/F JPEGs

Worst case buffer clearing time. -- This is the delay after a set of shots before you can remove the card. Some cameras won't shut down until the buffer is cleared.
6 seconds *
after 8 RAW frames
7 seconds *
after 4 RAW + JPEG frames

*Note: Buffer clearing times measured with a SanDisk Extreme III 8GB SDHC memory card. Slower cards will produce correspondingly slower clearing times.

This sounds like, if I get to Alaska and I see a glacier calving or a whale jumping, I'll only be able to take 4 RAW+JPEG pics at once, then have to wait 7 seconds before I can take more pics. I hope that's not right! Maybe I should go into my backyard and shoot a tree and see how long it takes for my camera to work. If I wasn't going on a cruise I might look for a new camera :(

GlennInEncinitas Loc: Encinitas CA

There are arguments to be made about whether it is worthwhile to get "faster" memory cards or not spend the money - how fast can your camera process photos? How fast can your computer download from the card?

Leaving that aside, Bestbuy.com is having an OUTRAGEOUS offer on one of the best SD cards. They are selling the Sandisk Extreme Pro SDHC card at a deep discount. Here is the link:

http://www.bestbuy.com/site/searchpage.jsp?_dyncharset=ISO-8859-1&_dynSessConf=&id=pcat17071&type=page&sc=Global&cp=1&nrp=15&sp=&qp=&list=n&iht=y&usc=All+Categories&ks=960&saas=saas&st=sandisk+extreme+pro+sdhc

marcomarks Loc: Ft. Myers, FL

Rule of thumb has been that a Class 6 card is more than adequate for still photos in any camera and Class 10 is necessary for video because the transfer rate is much higher for flowing video, no matter what GB of storage capacity the card is. I personally buy Class 10 cards for everything and leave it at that. 8GB for stills so I don't put all my eggs in one basket when shooting a lot, and 16 to 32GB for video although I've never even come close to filling one with family and friend video clips.

Some people can be satisfied with 200 horsepower in their car and others must have 500 although they rarely, if ever, use it. That's mostly why a MB/s race continues.

sloscheider Loc: Minnesota

When I'm shooting a dog show and have 15 gig worth of RAW images the class 6 card I used took nearly an hour to transfer all the images to my laptop. Using a good quality Sandisk Ultra 30MB/s card takes roughly 25 minutes. My laptop is a Toshiba i3 with 8 gig of RAM and a 750 gig hard drive.

I agree that if time is of no consequence you could save $10 and get the slower cards. I got 16 gig Sandisk Ultras on Black Friday for $20 and 32 gig cards were around $35 as I recall.

singleviking Loc: Lake Sebu Eco Park, Philippines

I believe that the bottleneck in the download to any computer is the speed of the USB bus. It has nothing to do with the speed of the SD card or CF card. USB 3.0 is twice as fast as USB 2.0 but downloads also are controlled by the program being used, the speed of the CPU and the mechanism where the data is being stored to (ie. HDD or SSD) SATA speeds at present, can only transfer and store data at 6 Gig/sec at best.
The read/write speed of memory cards is actually fully utilized in the specific camera and it's buffer and DSP chip as they process and then transferring data to your memory module thereby allowing space in the buffer to attain continuous high fps rates.

marcomarks Loc: Ft. Myers, FL

Do you import directly to hard drive with Windows Explorer or import through something like Lightroom? Are you using a cable instead of a card reader?

I've found LR4 to be exceptionally slow (go get a coffee with cream, play with my toddler, and talk to the wife for a few, type slow) about importing because it's converting RAW files as it goes, setting up library folders, and creating thumbnail views for them, while Windows Explorer only imports to a folder you created yourself and doesn't do anything else.

I don't use 16GB cards, just 8GB - 20MB/s PNY Professional, and a full one can download through my PC's card reader in 10 - 12 minutes or so.

Pepsiman Loc: New York City

Thank you very much for the info...

sloscheider Loc: Minnesota

So you're saying the reason the class 6 card took longer than the class 10 card is because of a bottleneck in the laptop? Explain the difference in time then... The only thing that changed is the card... same laptop, same bus speed.

I completely agree with you about card reader speed being dependent on machine capabilities, of course.