It looks to me as though your personal experience supports the hypothesis that a class 6 Sandisk Extreme III card performs at about the same transfer speed as a Class 10 Transcend card for bulk transfers.
That wouldn't surprise me. I'm also inclined to suspect that your K-7 might not be the limiting factor here. Back when I switched to using SDHC cards in my K10D I decided, based on the information I could find, that paying the additional cost of a class 6 card was a good match for the performance of the camera, but that the price premium for the Sandisk cards (which generally showed higher sustained transfer rates) didn't match my expected use. That was for a camera design now two and a half generations (and almost five years) old; I'd be very surprised to find that modern cameras had data rates that could be satisfied by a class 6 card. I believe somebody on Pentax Forums has measured the performance of these cards in a K-5, and shown a noticeable speed improvement. My personal experience with Transcend cards has been very good; I bought 2GB Transcend 150x SD cards when I purchased my K10D, and later on upgraded to 4GB and 8GB Transcend Class 6 cards. I haven't had problems with any of the cards, and both of the 2GB cards are still in regular use (one in the Olympus E-PL1, and one on the PS3 being used in a USB reader as a thumb drive). I wouldn't hesitate to buy Transcend cards again. I am aware of the prevalence of counterfeit Sandisk cards; I would only buy these from a reputable source. I think B&H qualifies; if I do find the cards to be fake I'm pretty sure I'll have no problems getting them replaced. On Wed, Jul 20, 2011 at 04:27:49PM -0400, Igor Roshchin wrote: > > John, > It sounds like a reasonable deal. > > I might just add (for what it's worth): > It is important to realize whether the K-5 can utilize extra speed > of the cart (if any). > > I've been using two 8GB SanDisk Extreme III Class 6 SDHC cards with > K-7, and three 8GB Transcend Class 10. I haven't seen any practical > difference in the speed with the K-7 or with the ImageMate USB 2.0 > Reader by SanDisk. > > Even though I didn't do any formal tests, I've been watching the > transfer rates with the card-reader, and I don't seem to see much of > a difference. > So, either both cards' transfer rate is above the capabilities of the > K-7 and the card reader (most likely), or the cards' transfer rates > are about the same. > > I am not sure if K-5 can utilize a faster write rate than K-7 can. > > Even though I had been concerned about Transcend's reliability, - so far > I haven't seen any problem with any of my 3 Transcend cards. > > Besides, Sandisk cards appear to be more likely to be counterfeit. > So, if I would consider Transcend for my next cards. > > > Igor > > > Tue Jul 19 12:57:11 EDT 2011 > John Francis wrote: > > > If you buy 2 or more, B&H will sell you 8GB Sandisk Extreme > > Class 10 SDHC cards for $20 each, with free shipping. > > > > The Sandisk part number B&H quote on their website is the > > one for the 30Mb/sec cards (aka Extreme III), so these > > should be good enough even for those who own (or who are > > considering) a K-5. > > > > You can still get cheaper cards - a Transcend class 10 > > card is about 2/3 of that price - but the extra bandwidth > > might make paying a bit extra worthwhile if you anticipate > > shooting fast enough to fill up the buffer, or shooting a > > lot of HD video. And most other places (including Amazon) > > still want $30 or more for the Sandisk cards, so $20 is a > > pretty good price for these (for today, anyway). > > > > According to Rob Galbraisth's SD card testing site, these > > perform quite well in a variety of (Canon or Nikon) bodies. > > > > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above and follow > the directions. -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
