Write speed halved in liveview - dropped frames w KB 1066x on 50D

Started by d4erla, September 02, 2014, 08:17:23 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

d4erla

This must be something trivial, but I've searched and searched and can't figure it out...

Benchmark gives me around 100 MB/s write speeds with a KB 1066x 64 MB card in my 50D. But when I run the test in liveview mode, its suddenly 45 or so (globaldraw off).

I know a reduction is expected, but from what I've seen it shouldn't be anything like this. I get around 20 s of raw recording in crop mode 25 fps before dropping frames....

It's driving me nuts, since I know I have the proper hardware for this!

Ps. Turned off auto lighting optimizer etc - as far as I can tell all the canon menu tricks are in place.

Walter Schulz


d4erla


Walter Schulz


d4erla

Fps override, 25 fps... Please let me know what else is relevant....?

But note however that the write speed drop reported by benchmarking happens in any case in video mode - crop or not. very slow compared to what others seem to be getting!

Happy to get a reply btw!

nikfreak

[size=8pt]70D.112 & 100D.101[/size]

d4erla

No - I have only one fast card unfortunately. The fact that speed are just fine in replay mode makes me doubt the card is problematic. Something makes it drop in movie mode. It does write at 60-70 when the actual recording starts, but the buffer fills upp quick at 1920 crop mode. Full sensor recording is fine. Benchmark really slow in movie mode, like I said above.

ayshih

Actually, I think there may some issue with the benchmark code, at least on the 50D.  The last time I ran it, a while ago now, it was unstable, and I didn't investigate it further then.

Don't worry about whatever the benchmark reports as long as you're getting the max rate (~70 MB/s) when actually recording.  The buffer filling up fast in crop mode is just a consequence of exceeding that record rate.
Canon EOS 50D | 17–40mm f/4L & 70–300mm f/4.5–5.6 DO IS | Lexar 1066x

d4erla

Ok. So continuous 1920 crop mode is not possible with a KB 1066x card on the 50d? Or did I have bad luck with this card? I do get >100 MB/s in replay mode.