Here's a few deals on Samsung Media Cards you can't ignore. For GH4 owners this could also be good news. I've had a few days working with these Samsung SDHC cards and "so far" every bitrate/framerate i've been throwing at it has had no errors.
(yes I have a card collection)
Turns out with a max bitrate of 200Mb/s (bits) the speed requirements for your SDHC cards need only be 25MB/s (Bytes). Of course there's no guarantee the write speeds are 'sustained', but these Samsung SDHC cards are rated at 40MB/s Write and 80MB/s Read speeds, leaving a little bit of additional head room. If you plan to shoot 4K this actually drops down to 100Mb/s (less data rate) which means your card should support a constant read/write of at least 12.5 MB/s.
Just for kicks, here's a screengrab of the Samsung SDHC cards using the BlackMagic Disk Speed Test on my Mac.
Now if you're curious as the type of numbers a Sandisk Extreme Pro SDXC (found here) puts up, here's a screen grab. You can see the Read/Write speeds are much faster - but yes of course more expensive.
Another Samsung bundle is available for microSDHC / microSDXC Cards which work great for your GoPro Hero3+ cameras or anything that requires these small cards.
Samsung " 3 PACK" Pro Class 10 (UHS-1) 32GB microSDHC Flash Card with Adapter, Up to 70MB/s Read & 20MB/s Write Speed
For the GH4 camera, you need a card that can sustain a write speed of 25MB/s, which in most cases I can't seem to even get close to with my footage. Most of the stuff i'm shooting still sits way below this max requirement. Of course if you want something with even more than the Samsung 30MB/s, here's a more affordable Sandisk Extreme 45MB/s SDXC Card.
My tests below show that it can at least sustain over 40MB/s read/write speeds and less than a $1/GB. Check it out (found here)