How fast can one write files from a PC to the GH2 using a class 10 card?

Sun

Sun

Carbonite Member
I have the USB3 ports and I wondered what the writing speed was from the desk top to the card in the GH2 should be?

I'm assumed this is how one knows the actual writing speed of the SDHC card?

I tested my class 10 card by dragging and dropping a 1.5Gb file and the transfer speed was only 5.25Mb per second. I did the same test on a class 6 card and I had identical results.

Both SDHC class 10 and 6 cards bog down in rapid frame capture mode. Is the camera writing speed limited or is this a card problem?
 
This can be a number of problems.

I do not have a GH2.

Class 10 card should have a MINIMUM speed of 10 MB/s regardless of write or read speed. Of course write speed is always slower, so the card should be a minimum of 10 MB/s write.

Problem can be that the GH2 does not do fast transfer speeds. Get yourself a nice little SDHC card reader, and use that.

Maybe it was 5.25 Mb/s at that specific moment in time. Although low 5.25 is still low, what is your average.

Maybe you are hitting the buffer of the camera with your rapid capture mode.

Check out h2testw and test your card. Maybe you have a faulty or fake card?
 
Sun said:
I have the USB3 ports and I wondered what the writing speed was from the desk top to the card in the GH2 should be?

I'm assumed this is how one knows the actual writing speed of the SDHC card?
Click to expand...

You're testing the speed of the USB subsystem on the GH2 as well as the file system interface of the GH2 as well, so this is not a good test.

The traditional way to test write speeds on a camera, is to fire off a series of shots eg 4 RAW shots in a row and time how long it takes to write them out to the card using the activitiy light on top. The RAW files should be in the range of about 20megs each, and you can easily generate 4 of them in a little over 1 second.

Unfortunately, testing on a computer is also not valid, since the controller in the GH2 is not the same and the in-camera speed is really the one that counts.
 
It can fire off 8 standard RAW files between 3.34 and 4.11 seconds on average. Yet under the fine RAW files setting it can take 5 pic between 1.93 and 2.05 seconds?

I think the buffer in the GH2 allows the first 4 or 5 pics even in the RAW format to be spooled off and stored in its memory after that the card is backing up?

It can shoot 8 images in the Jpeg format in 3.12 seconds and 16 jpeg in 7.7 and 8.2 seconds, the 15 image was the last of the fast pics.

Would an SDXC card help GH2 write faster? I've tried a few Class 10 SDHC cards and they all seem to transfer at around 5.2mb to 6.5Mb from the PC to the GH2. I didn't know this could be an inherent limitation of the GH2 transferring system.
 
Try it with 5 pics, fine RAW with the lens cap on, ISO 100, 1/1000 shutter manual focus and exposure. Time how long it takes from the 1st shot till the red activity light or icon on the LCD goes out. Divide the total size of the 5 files (probably 100megs or so) by the total time it takes to write it all out, and you'll have the actual max write speed.

I know that on my GH1, I can't take a video until the "writing icon" on the LCD goes out, so this should be a fairly accurate test.
 
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