SD memory card speeds

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Hi guys,

Just a quick question on memory card speeds / rating. Given the huge difference in price between a Sandisk Extreme II and Extreme III SD cards, it got me thinking about whether I really needed the extra speed that the Extreme III can offer (30mb/s versus 15mb/s).

It's easy to realise that one card has the ability to dave data faster than the other one, and it's obvious what impact this will have on everyday use of my camera (450D). What I don't know is the quantum of this impact.

Has anyone actually compared the two? What were the real life impacts like? Is there a significant real life difference in, say, FPS in continuous shooting?

TIA :)
Nami
 
are some of the top end mem cards not pointless unless you have a top of the range current camera? I'm sure I read something about that because the camera cant keep up. Cant remember where i read it though. :confused:
 
I'm looking at getting a new memory card for the 300d(compact flash) and trying to decide bettween the various speed ratings(think I'll be going for 4gb as not sure if the 300d takes 8gb, also 4gb should be plenty as the 300d is a 6mp camera), as I'm thinking of upgrading to a x0d in the future trying to decide if its worth paying the little extra now on say the sandisk extreme 3 over the ultra 2(altho from what I've read its not till you get to the 5dmk2 that you see the speed benfit of the cards above 10mb/s, would link to it but its mentioned in a customer review on one of the compatitor sites).

another thing the kingston 133x is like 3rd the price of the sandisk extreme 3(kingston 4gb is ~£10 and sandisk extreme 3 £25-£30) but from the description is 25mb/s read, 20mb/s write which is not too far short of the sandisk extreme 3 claimed speeds(30mb/s). 2 things the sandisk has over the kingston(apart from the slight speed advantage) are the 'free' data rescuse cd and zip pouch that holds 2 cf cards).
 
Thanks for the responses.

I've had a good look on that site (as well as doing some other googling) and found some interesting information. There is some updated information for the 450D: http://www.robgalbraith.com/bins/camera_multi_page.asp?cid=6007-9424

This is interesting, as the speeds are suddenly much greater than those for the 350D, and the differences between the cards becomes much more apparent.

Having done other research, it seems that whilst SDHC class ratings are the best indicator of the minimum speed of a card there is still no obvious way of knowing which is the best performing card due to the usual marketing hype. Many class 6 cards (minimum 6mb/s) appear to claim that they can write at speeds of up to 30mb/sec, but don't specify for whether this is continuous or burst (or how long the burst may be for) so it's still not easy...... Couple this with the fact that a Class 2 card could outperform a Class 6 card (in theory, and has been seen in practice also) , and it still feels like a mindfield to me....

You're more likely to see a difference when transferring files to your PC from the card.

This is one area of performance that personally I'm not concerned with. I'm happy to start the transfer and make a cup of tea! So worth noting that I'm focused only on in-camera performance.

I think I might go for a Lexar Professional 4Gb as it seems to at least equal (if not outperform) the equivalent SanDisk card, and it's significantly cheaper also (33% cheaper!). Anyone have any experience of these?
 
The area that I find is greatly adffected by memory card speeds, is how long it takes to clear the buffer after a high fps sequence. For example if im shooting a bird in flight or sport, and hammer the camera at 8fps, the buffer quickly gets full. I then have to wait for the buffer the transfer to the card. Most of the time this isn't a great problem, but ocasionally I will miss shots as the camera isn't ready in time.
 
This is predominantly why I ask about the speed of cards. I use continuous shooting quite a bit, even if it's for portraits. You know what it's like when you get composition and exposure all just right and then someone pulls a funny face...... continuous shooting is great for this scenario!

I borrowed a cheapy SanDisk card a few weeks back and it took a significant time to save following a burst fire, so I want to ensure I don't get this really. But I also want value for money, which to me the Extreme III cards don't really offer.

I've ordered a Lexar Pro SDHC 4Gb so will let you know what it's like after I've used it in anger on my holiday to Sweden :)

Cheers for your responses.
 
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