I think it's fair to say that UDMA is definitely not a requirement, at least not if you consider that a lot of people are using non-UDMA cards without problems. That said, if you have a really important project, or have the budget, then why not use UDMA.

Among other smaller and slower-than-UDMA cards I own, which have all worked fine, I've also been using a 133x Kingston 32gig card I got from NewEgg for $60 (that's right, $60 for 32gb) without problems. On a rare occasion I see one light on the buffer, but it's always gone away before going to two lights, and I've never seen a dropped frame. Yes, it is a bit slower, and I can tell sometimes when rapid-firing 21mp stills, but the thing works fine and the price is oh so right...

In reviewing the specs on the cards, versus Canon's stated requirements, these cards double the maximum write speed, as I understand it. In fact most 133x cards seem to do so. As far as stills during recording. I have done that without error too.

I do wonder if the 16 would write as well, and will probably try one at about $35.00

Write Indicator
 

I have an 8gb Sandisk Extreme 3 that freezes my 5d. The write indicator bars fill up and the camera freezes. I have to pop out the battery and I lose the current take. It is a little frustrating and happens at random times. Any suggestions for correcting this? I have two slower cards that don't have this issue.

Thanks Guys! Problem solved courtesy of transend card reader. I was able to transfer my 4gb(HDvideo) files for only 3mins.

Card Write Indicator
 

I have an 8gb Sandisk Extreme 3 that freezes my 5d when shooting video. The write indicator bars fills up and the camera freezes. I have to pop out the battery and I lose the current take. It is a little frustrating and happens at random times. Any suggestions for correcting this? I have two slower cards that don't have this issue.

It appears your card crashes, quits writing, the 5D2 fills up its buffer waiting for the card, and then the 5D2 gets locked up waiting for a write operation to finish. It must not have a time-out for giving up on the card.

It sounds like a bad CF card. Just replace it.

Cheers

Nigel

I'm using a Transcend 32GB 133x I bought for around $70. Thought I'd try it out because the cost was reasonable and I could always use CF card for my other cameras if it choked on the 5DmkII.

I have used this card for a couple days of casual family shots (and lots of video) and it worked flawlessly -- didn't even register any buffer bars. None!

I think the UDMA cards are really nice, but they're not essential.

p.s. The above member who was complaining about a Sandisk ExtremeIII CF card causing problems -- I'm not an electronics engineer, but it sounds like a defective card to me. I have an ExtremeIII 16GB card and it works fine, never had any problems.

I have 3 of these cards and they've not shown this symptom at all

High end CF cards compared
 

Here's a good review of high end CF cards. Personally, the most interesting thing to me is the Addonics ADSACFW SATA CF reader listed on page 9 of the article.

Roundup: CompactFlash Cards For Professionals : Compact Flash Powerhouses Reviewed - Review Tom's Hardware

Frankly, none of the cards look bad. I'm more interested in reliability and cost per MB than the last 10% of performance.

Thanks for posting that link! But I didn't see the HoodMan RAW 300x UDMA card in there.

I've been using a $60 133x Kingston 32gig card without problems. Now that's a price/size/performance tradeoff I can live with!

Have you tried shooting stills in RAW format with the 133x cards, shooting as rapidly as possible? I have a 16GB Transcend 300x card which will has allowed me to shoot 21 RAW (with no embedded JPG) shots before the buffer filled and the camera slowed down. I also have a 4GB 133x card which only gave me about 17 shots before the camera slowed down. Neither card has any trouble with video, however.

Julian

I always like Ron Galbraith's website.
Rob Galbraith DPI: Canon EOS 5D Mark II

And what's the minimum speed the 5D2 needs for video again?