CF Card can't keep up - 1DMK3

So I noticed a problem while shooting the other day in ai servo, hi fps. I'll fire off 10-15 frames and it takes my camera a long time to catch up and finally display an image on the LCD - the red light stays on for a good 15 seconds. I didn't realize this at first and because it was still buffering I lost shots.

I currently have a Sandisk Ultra 30ms 8GB CF writing Hi JPEG and a Sandisk Ultra 8GB SD card writing RAW files. They are recording simultaneously.

Could the problem be that they are both writing simultaneously ?

Hi alexxn...Don't know the maximum Burst for the 1Dm3, but it is 20 for the 1Dm4 for RAW+JPEG so I suspect the 1Dm3 is similar...At 10-15 shots, you're pushing close to this...Particularly if either of your cards is slow writing.

SanDisk Ultras are slow cards. Get yourself a SanDisk Extreme and you'll get a lot more shots before hitting the wall.

Ultras are 30MB/s, Extremes are 60MB/s.

I have a sandisk extreme 8gb 60mb/s card and it does quite well. But I shoot a lot of bursts so am going to get the sandisk extreme pro 16gb 90mb/s card. I shoot RAW and have it to auto switch media when one card is full.

It may be that you technically are writing twice as much data, is there a reason for you to have both jpg and RAW?

Brendo666 wrote in post #14534499
I have a sandisk extreme 8gb 60mb/s card and it does quite well. But I shoot a lot of bursts so am going to get the sandisk extreme pro 16gb 90mb/s card. I shoot RAW and have it to auto switch media when one card is full.

It may be that you technically are writing twice as much data, is there a reason for you to have both jpg and RAW?

Actually I don't need both, I think I'll get one good card and have it write to one.

I was thinking having it write to both as a backup.

As there was (is?) a rash of counterfeit Sandisk cards out there, perhaps this might the situation here?

I suspect the lag is actually the sd card.

You are sending large Raw files to it and from experience the sd cards are not as good at this.

itsafastworld85 wrote in post #14534927
I suspect the lag is actually the sd card.

You are sending large Raw files to it and from experience the sd cards are not as good at this.

Good point, I'm going to try to record only to the CF card and see what happens.

TeamSpeed wrote in post #14534910
As there was (is?) a rash of counterfeit Sandisk cards out there, perhaps this might the situation here?

Maybe ?

I bought them brand new from Costco 2 years ago....

alexxn wrote in post #14535019
Good point, I'm going to try to record only to the CF card and see what happens.

If you really want both types of files try recording RAW to the CF card and jog to the SD card.