emmee

I just got a 2GB Ridata Pro SD memory card claimed to be 120X speed. I'm comparing it to an older 256 MB Sandisk UltraII CF card in my Axim X51v.

In a quick speed test I'm copying a 4.1 MB file from internal flash to either the SD or CF card. The file copies to the CF card in about 5 seconds. It takes about 15 seconds to copy to the SD card! The CF card looks 3 times faster.

Copying the same file back to internal flash takes about 11 seconds for the CF and 6 seconds for the SD card. For reading, the SD card looks twice as fast as the CF!

From what I've read on Aximsite and other places SD and CF cards are supposed to have comparable speeds in the X51v.

Since I "stole" the CF card out of my Olympus camera it's still has the original raw fromatting. The SD card is formatted in FAT32. Since I'm dealing with one big file here, I wouldn't expact formatting to make much difference.

I also got an Ezonics SD2GO USB adapter with the Ridata SD card. Using this adapter it takes about 5 seconds to write a 55 MB file to the SD card, so it looks like the card itself is not the limiting factor. This time is the same with my Kinsgston 512 MB DataTraveler USB stick. So the write speed is 32 times faster in a PC as compared to the X51v!!

Is this similar to what others have seen or am I doing something wrong?

bigbop

The flash card drivers on the Axim X50 are not optimized at all, which is a pity. However with that said, at least a slower write means that the device is not being pushed to its limits and the data 'should' be written without any corruption.

emmee

Originally Posted by bigbop

The flash card drivers on the Axim X50 are not optimized at all, which is a pity. However with that said, at least a slower write means that the device is not being pushed to its limits and the data 'should' be written without any corruption.

I'm not sure that's the problem. I just compared writing speed of the internal flash with that of the Cf and SD cards. One change is that I formated the SD card to FAT32 with 16 k cluster size which approximately doubled writing speed from the 4 k cluster seting.

For writing a 46.7 MB file the internal flash took 5.5 minutes, the SD card took 2.5 minutes and the CF took only 1.25 minutes. So again, the CF card blows away all others.

As for the slow write times being better for preventing data corruption, I'm not sure how you can come to this conclusion without knowing where the delays are coming from. In any case, my SD card writes over 30 times faster in the USB adapter, so its far from being pushed in the AXIM.