Go Back   Steve's Digicams Forums > Digicam Help > Memory Cards, Microdrives, Card Readers

Reply
 
Thread Tools Search this Thread
Old May 26, 2007, 9:47 PM   #1
Senior Member
 
Join Date: Feb 2006
Posts: 172
Default

No shortage of buzz about the latest and greatest speeds in flash media. Ran into a guy recently who boasted he would never use any card less than a certain speed. I believe it was 80x.

Is the speed more of a factor in actual shooting, or, in downloading to computer? Some of both?

leeraff is offline   Reply With Quote
Sponsored Links
Old May 27, 2007, 2:12 PM   #2
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

That all depends on the camera.

Some cameras have *much* faster interfaces to media compared to others.


JimC is offline   Reply With Quote
Old May 27, 2007, 4:27 PM   #3
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,544
Default

leeraff wrote:
Quote:
Is the speed more of a factor in actual shooting, or, in downloading to computer? Some of both?
Usually, people are more patient when uploadingphotos to their computer. (You upload from small devices to large devices; you download from large devices to small devices.)

Speed usually matters most when people are trying to take sequential shots. The camera must transfer one photo to the flash memory card before it can take another, and if the card isn't as fast as the camera, then the user might have to wait a while before the camera will take the next shot. That's when people tend to get impatient, so that's when the speed of the flash memory card usually matters most.
TCav is offline   Reply With Quote
Old May 27, 2007, 9:02 PM   #4
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

leeraff

I'm assuming from your previous posts that you have a Canon EOS-30D now.

Rob Galbraith has some tests of popular media types in it at this link:

http://www.robgalbraith.com/bins/mul...?cid=6007-8478

The EOS-30D looks like it tops out at around 7MB/Second with a card capable of much faster speeds. So, you'll tend to get diminishing rates of return once you get to a certain card speed with it.

In other words, you may buy a card that's twice as fast and only see a small improvement, since the camera is not capable of writing to media at the 40MB/Second some of the newer cards support. IOW, I probably wouldn't rush out and buy an Extreme IV instead of an Extreme III. ;-)

See Rob Galbraith's tests for how some of them compare. Just keep in mind that card size can make a difference (FAT versus FAT32 comes into play), and manufacturers do tend to change components for the same card model from time to time (for example, a newer Ultra II may be faster than an older Ultra II).

Some cameras can write to media faster. For example, my discontinued Konica Minolta Maxxum 5D can write at almost 9MB/Second to a faster card, and the new Sony DSLR-A100 can write at almost 14MB/Second with a fast card like an Extreme III.

From my perspective, it's a real good idea to use faster memory cards with these models, since they have relatively fast write speeds to media, combined with a smaller buffer (fast internal memory) compared to a model like the EOS-30D if you are doing a lot of shooting in continuous mode (especially shooting raw).

Your EOS-30D has a larger buffer (fast internal memory). So, you're not going to see any difference in your shooting speed until that buffer fills up (and that's probably not going to be until you get to around 35 or 40 shots shooting in JPEG with a faster card, since it's writing while you're shooting before the buffer is full).

At that point (full buffer), the camera will slow down to match the speed it can write to media (and flushing to media for another full speed burst will be faster or slower, depending on the card speed).

Unless you're doing a lot of continuous shooting in raw. you may not need a faster card.

Even a very slow card will allow you to shoot just as fast until the camera's internal buffer is full. If you never fill it up (because you don't shoot in continuous mode much), you'll never see any speed difference. But, if you do fill it up using a slower card, your "buffer full" frame rate will slow down, and it will take longer to completely flush the buffer to the memory card.

A faster card can also help with browsing of images in the camera (faster load times).


JimC is offline   Reply With Quote
Old May 27, 2007, 11:27 PM   #5
Senior Member
 
Join Date: Feb 2006
Posts: 172
Default

Wow. Thanks a lot. Great info. I'd say that pretty well answers my question.

Just curious as the prices have come down so much, the difference in an Extreme III and Ultra? IV are negligible with rebates. (I'd peronsally hate to look back and see what my first gig worth of memory cost comprising of about 5 or so individual cards. Remember back spending $100 for 256mb or so? Spending about the same amount to double to a whopping 512mb?)

Yes, JimC, I have the 30d and, no, I don't see myself filling that buffer on a regular basis. For the $15 or so dollars more and Galbraith's rating as the IV being best (currently) for the 30d...

Finally, thanks for the correction on upload vs download. Makes sense.

All said and done, sounds like speed does come into play for both shooting performance and "uploading" to computer. Thanks for the detailed info.


leeraff is offline   Reply With Quote
Old May 28, 2007, 9:17 AM   #6
Administrator
 
Join Date: Jun 2003
Location: Savannah, GA (USA)
Posts: 22,378
Default

leeraff wrote:
Quote:
Wow. Thanks a lot. Great info. I'd say that pretty well answers my question.

Just curious as the prices have come down so much, the difference in an Extreme III and Ultra? IV are negligible with rebates. (I'd peronsally hate to look back and see what my first gig worth of memory cost comprising of about 5 or so individual cards. Remember back spending $100 for 256mb or so? Spending about the same amount to double to a whopping 512mb?)
I can remember spending close to $300 for a 128MB card (from an online discounter that had the lowest price I could find) not long after Lexar introduced their 8x 128MB USB Enabled CompactFlash Card. lol

Memory prices are dropping. But, with the amount of devices that use flash memory anymore, that's not surprising.

As for the price differences, you'll need to decide if it's worth it to get the "latest and greatest card".

Yes, that 2GB Extreme IV at the top of Rob's list tests faster. But, there is very little difference between it and the other Sandisk Cards in that size.

Here is what Rob measured shooting in raw using 2GB Ultra II, Extreme III and Extreme IV cards:


6.780 MB/Second with 2GB Extreme IV
6.415 MB/Second with 2GB Extreme III
6.406 MB/Second with 2GB Ultra II

So, even though the Extreme IV is rated at 4 times as fast as the Ultra II by Sandisk, Rob saw less than 6% improvement between them in a 30D. The camera becomes the main bottleneck with cards that fast.

If the price difference was very small (and I don't like rebates), I might go with an Extreme IV anyway. But, I would not personally spend much more to get one (because of the small gain you'd see). If you never filled the buffer, you'd see no real benefit at all.

JimC is offline   Reply With Quote
Old May 28, 2007, 10:00 AM   #7
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,544
Default

I'd like to add a few points to the excellent comments that JimCmade:

1. The difference in cost between an Extreme IV and an Extreme III isn't very much, and just because your current camera can't take advantage of the faster card doesn't mean your next camera won't.

2. The throughput ratings that manufacturers use when hawking their products should only be used when comparing products, not as an indication of the actual performance you will see. Different manufacturers test their products in different ways, and their performance figures will include several things that go on in the background (like reading and writing the File Allocation Table, verifying write operations, etc.) So the numbers they provide for throughput will not match up to what you will experience if all you look at is how long it takes to read or write a file.
TCav is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 11:29 PM.