1DS3 - Writing to both cards slower?

I'm thinking of utilizing both card slots on my 1ds3

My query is, would writing full sized Raw files to CF (which I already do) and then to Full Jpeg on the SD card make for slower burst mode?

Or would I be better writing Raw to both as there's no need for Jpeg compression?

I've tested this with a Transcend 300x UDMA CF card and a Transcend Class 6 SDHC card.

There was practically zero speed difference when shooting raw to CF + large jpeg to SDHC versus shooting just raw to CF. In both cases the buffer was fully cleared in about 15 secs. When shooting raw to both cards it took a couple of extra seconds to write the files to both cards.

The jpeg processing doesn't seem to slow down the camera, it's the size of the raw files that increases the transfer/write time and takes those extra seconds.

Gel,
Nope, I don't think so.... Here's a Q/A from Canon's site for the Canon 1DIII (note: not the 1Ds3, but I assume the sample principle applies)

How are you liking the 1Ds3? I don't like the time it takes to preview a photo after taking it (compared to the 5DII).

BTW. I gripped one of my 5DII, and you're right... a gripped 5DII is more monstrous than a 1Ds3. Although I do prefer the ergonomics of the 1Ds3 better.

-David

the 1Ds3 and the 1D3 are similar in a lot of features.... So my last response was based on this fact:

http://www.usa.canon.c​om …ArticleAct&arti​cleID=1886

-David

dKweddings.net wrote in post #10883356
the 1Ds3 and the 1D3 are similar in a lot of features.... So my last response was based on this fact:

http://www.usa.canon.c​om …ArticleAct&arti​cleID=1886

-David

They are not similar in terms of file transfer speeds. The 1DsM3 is UDMA-capable, the 1DM3 is not. The 1DsM3 has a faster file transfer rate when using UDMA CF cards.

Petri wrote in post #10883365
They are not similar in terms of file transfer speeds. The 1DsM3 is UDMA-capable, the 1DM3 is not. The 1DsM3 has a faster file transfer rate when using UDMA CF cards.

Oh. My mistake. In that regards.... I don't have any information of my own to add.

-David

The burst of Raw is longer than Raw + JPEG, it always cuts down slightly on the burst size. Then once the buffer is used up it can take longer to write to both cards if you have a slow SD card in the second slot. It writes simultaneously but it has to wait for the first shot to write to both cards before it starts on the next shot.