Thanks Godfrey for this detailed answer to my question that was, I must admit, rather fuzzy.
I was just curious about actual ratios. The imbalanced write vs read speeds quite makes sense to me, as the "80X speed" we are talking about is about comm, while the Flash techno has its own physical limitations, and comm time put aside, write latency is far greater than read latency. While writing, the comm is a comparatively small part of the total time, and because reading flash is much faster, while reading the same amount of data, the same comm time is comparatively more important, and has more impact to total time. I don't care much about read time (I'm very seldom in a hurry uploading files to my PC), and the DS buffer is usually enough for me. After all, I may buy one faster card (>=60X) just for the few situations in which I tend to curse the slower cards (although I haven't seen ANY 80X 1Gb card in this price range here yet!). Patrice 2006/3/28, Godfrey DiGiorgi <[EMAIL PROTECTED]>: > It's hard to be precise without more precise data, Patrice. > > Basically, an 80x card has the potential of transferring data at > about twice the speed of a 32x card, but that potential is > constrained by how fast the camera's data bus can support. The *ist > DS body can just about use the full potential of a 60x card's write > speed, cards faster than that will not appear to be any faster when > used in the DS. Depending upon how slow your current cards are, you > could see anywhere from substantial to relatively minor gains in > write speed, in camera, with an 80x card. > > I know that comparing my 45x PQI card to my 60x Transcend or Sandisk > Ultra II cards, I see about 15-25% reduction in write time on bursts > of five frames. And comparing an old 32x Sandisk card to the Ultra > II, the difference is closer to twice as fast. > > The differences are larger when it comes time to upload to the > computer. With a good USB 2.0 card reader, the Ultra II cards achieve > transfer times in the [EMAIL PROTECTED] range where the slower cards > take correspondingly more time to deliver data. A full Ultra II 1G > card transfers its data to hard drive in about 2.5 minutes, where > that same old 32x card takes just shy of 5.5 minutes. > > If you're more of a "one at a time" picture taker, the difference in > performance in-camera might never be noticeable. The camera's > buffering will just perform the writes while you go on with taking > other pictures. > > Godfrey > > On Mar 28, 2006, at 7:01 AM, Patrice LACOUTURE wrote: > > > For my info, can someone give an idea of write times for such a 80x > > card with a *ist DS? I only have cheap/slow cards now, and I'm > > wondering if I should "invest" in at least a few fast ones, as I shoot > > RAW.
