Which is faster

[Temetka]

SD or Compact Flash?

I ask primarily because of ReadyBoost. So before I run out and buy an adapter and card, which is faster?

Which lasts longer?

I do know that gb for gb, CF seems to be more expensive. Considering that I would be using it for ready boost and the given cheapness of SD cards maybe they are the better way to go.

Your input here.

Thanks.

[jamiphar]

I don't happen to know for sure, but it seems that most higher-end cameras use the CF cards. We use 50X 1 GB and 2GB cards in our Rebel XT it they don't slow down the buffer at all. But maybe SD cards wouldn't slow it down either.

[dorin]

that's exactly the thread i wanted to start too!

i'd like to switch to sd for my new 30d

the advantage is obviously: i'll give up carrying one extra cable. the pcmcia if insterted has to be turned off...story short an sd will be just lovely, and a adapter for sd to cf are very cheap.

so, any ideas which is faster?!

cheers,
dorin

[rkawakami]

Some flash cards (CF and SD) will have "speed" ratings on them. Something like "50x", where "x" is the old CDROM 150KBS transfer rate. If you would like to believe the marketing hype, simply buy the card that has the highest rating at the price you are willing to pay.

All flash memories have a limited lifespan (known as write/erase cycles). Typically they are several hundred thousand to a few million cycles so you should not have to worry about the card going bad. Unless, of course, you are considering using a flash card as a substitute for a hard drive (e.g., ReadyBoost). With the wear leveling algorithm built into the flash cards (which spreads out the usage so that no single area of memory is written to or erased more than the rest), you could still probably get several years of usage out of the card before "sector" errors pop up. Depends upon how often the data gets changed. If you have enough physical memory, then you wouldn't be using that virtual drive anyway. If you don't have the physical memory and have to rely on the swap file a lot, then the flash memory will be exercised more and failure will come sooner.

I don't have any hard numbers that say you will get "x" amount of improvement using flash memory over a hard drive, but I would say that is has to be better simply because it's non-mechanical. One speed limitation is the USB port that you are plugging the flash drive into. My understanding is that even the most recent flash drives are still not running at the maximum transfer rate of 480Mbps that USB 2.0 offers.

ReadyBoost seems to be an affordable way of speeding up the OS because you can get a 1GB flash drive much cheaper than a 1GB SODIMM. That said, I would still opt for increasing the size of the system memory than to use a "band-aid" approach such as this.