Class Speed rating for SanDisk Extreme IV

[allenbirnbach]

The recent story on dpreview about video says that a Class speed rating of 6 is best for CF cards.  I cannot find info on the SanDisk site about what the rating is for the Extreme IV cards.  If someone knows this information, I'd appreciate hearing what that is, as I would like to buy some larger capacity cards for my Canon 5D MkII.

[Gary Brown]

The recent story on dpreview about video says that a Class speed rating of 6 is best for CF cards.

SD and SDHC cards have class ratings. As far as I know, CF cards don't use "class" ratings, but just give a number of MB/s.

The Extreme IV CF card press release here says they're up to 40 MB/s.

[allenbirnbach]

Yes, I've seen the speed ratings, but I guess that is the maximum the card is capable of.  The Class speed rate apparently indicates  the slowest  rate which I guess affects the performance with video.  Since the article talks about it, I have to think the number exists for the Extreme cards.  It's just not apparent on the website, or in any search I do on Google.  Maybe someone can point me in the right direction. :-)

[terence_patrick]

The new 90mb/s Extreme Pro cards are UDMA 6, the 60mb/s Extremes are UDMA 5, so my guess is that the 45mb/s Extreme IVs are UDMA 4? The Extreme III cards, which are 30mb/s have worked just fine for the 5DMk2 in terms of video (for my studio at least). We've used footage for two major brand commercial spots shot on the 5DMk2 and 16gb Extreme III cards without a hitch.

[allenbirnbach]

Thanks for the info, particularly as to your experience with the 30mb/s speed.  Much appreciated.

The new 90mb/s Extreme Pro cards are UDMA 6, the 60mb/s Extremes are UDMA 5, so my guess is that the 45mb/s Extreme IVs are UDMA 4? The Extreme III cards, which are 30mb/s have worked just fine for the 5DMk2 in terms of video (for my studio at least). We've used footage for two major brand commercial spots shot on the 5DMk2 and 16gb Extreme III cards without a hitch.