CF writes 3 times faster than SD

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 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.

I 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?

[PaulSM]

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 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.

SD was not designed for FAT32.
You'll need to reformat your SD card with a formatting utility from sdcard.org and redo your test then I'll believe you.

SD was not designed for FAT32.
You'll need to reformat your SD card with a formatting utility from sdcard.org and redo your test then I'll believe you.

So you think I'm making this stuff up??

I've never heard that SD was not "designed" for FAT32. Where have you seen this documented?

I DID format in FAT and FAT32 with the same results. Is Windows XP not capable of formatting FAT even though there's an option for it?

There's at least one other poster here that reports that FAT and FAT32 give the same speed....

[PaulSM]

So you think I'm making this stuff up??

I've never heard that SD was not "designed" for FAT32. Where have you seen this documented?

I DID format in FAT and FAT32 with the same results. Is Windows XP not capable of formatting FAT even though there's an option for it?

There's at least one other poster here that reports that FAT and FAT32 give the same speed....

You may want to check out this site: sdcard.org

You may want to check out this site: sdcard.org

I did. I saw that they offer a formatting utility but not anything about what formatting SD was "designed" for.

SD was not designed for FAT32.
You'll need to reformat your SD card with a formatting utility from sdcard.org and redo your test then I'll believe you.

Well, I tried the command prompt format to FAT in Windows as well as the Panasonic utility from sdcard.org. The results for writing speed are the same as what I got before: SD card is much slower than CF for writing!!

So there goes the "SD was not designed for FAT32." theory!:exc:

I just realized another thing: if SD cards were not "designed" for FAT32, then why does my card work so well in a USB adapter when formatted in FAT32??

Still waiting for a credible source to back up your "design" statement. Till I see it, I WON'T BELIEVE YOU!!

interesting experiment. maybe it's the way the x51v handles the sd & cf cards?

I suggest you put the SD in the CF slot using an adapter and repeat test to see if you get a different result :)

[PaulSM]

Well, I tried the command prompt format to FAT in Windows as well as the Panasonic utility from sdcard.org. The results for writing speed are the same as what I got before: SD card is much slower than CF for writing!!

So there goes the "SD was not designed for FAT32." theory!:exc:

I just realized another thing: if SD cards were not "designed" for FAT32, then why does my card work so well in a USB adapter when formatted in FAT32??

Still waiting for a credible source to back up your "design" statement. Till I see it, I WON'T BELIEVE YOU!!

Will this make you BELIEVE ME? :headscrat
http://panasonic.co.jp/corp/news/off...n060309-3.html
and this
http://consumer.usa.canon.com/ir/con...&modelid=12812

[PaulSM]

Here's the snapshot, just in case:

Here's the snapshot, just in case:

Not sure where this comes from, but I'm glad you posted it. Is handily proves that SD cards DO support FAT32!!!


Just look to see what it says in the "File System" section:

Current SD Memory Card complies with FAT16 or FAT32

The other links certainly DON'T support your claim either.

The Panasonic press release does not mention anything about SD cards not supporting FAT32.

The Canon link mentions that SD cards CAN be formatted in FAT32:

Some Windows Operating Systems allow the formatting of memory cards in the FAT system as well as other file systems such as FAT32 and NTFS.

Canon cameras may not support FAT32 but SD cards sure do!


Based on your "evidence" I'm still at a loss as to how you came up with the "SD was not designed for FAT32." theory!

Good Grief!, give it up....

interesting experiment. maybe it's the way the x51v handles the sd & cf cards?

I suggest you put the SD in the CF slot using an adapter and repeat test to see if you get a different result :)

I think you're right, the Ax clearly handles the two cards differently.

As for your suggested experiment, it's a good idea. I don't have an adapter and am not going to buy one just for testing. Running this test may not be all that conclusive since it introduces another variable with the adapter. If anyone else can try this I'd be interested to see the results.

[PaulSM]

Not sure where this comes from, but I'm glad you posted it. Is handily proves that SD cards DO support FAT32!!!


Just look to see what it says in the "File System" section:


The other links certainly DON'T support your claim either.

The Panasonic press release does not mention anything about SD cards not supporting FAT32.

The Canon link mentions that SD cards CAN be formatted in FAT32:

Canon cameras may not support FAT32 but SD cards sure do!


Based on your "evidence" I'm still at a loss as to how you came up with the "SD was not designed for FAT32." theory!

Good Grief!, give it up....

I think, you'll need glasses. It says "FAT12" NOT 32

[0gopogo]

Guys, get this discussion back on the ground. You are both right and wrong at the same time.

[PaulSM]

Not sure where this comes from, but I'm glad you posted it. Is handily proves that SD cards DO support FAT32!!!


Just look to see what it says in the "File System" section:


The other links certainly DON'T support your claim either.

The Panasonic press release does not mention anything about SD cards not supporting FAT32.

The Canon link mentions that SD cards CAN be formatted in FAT32:

Canon cameras may not support FAT32 but SD cards sure do!


Based on your "evidence" I'm still at a loss as to how you came up with the "SD was not designed for FAT32." theory!

Good Grief!, give it up....

Either you don't know how to read or just plain ignorant

I did a Google search on the subject and every article I read says you can format an sd card with fat32.Some even advice the larger sd cards work better with fat 32.