balazer wrote:This discussion is rather silly, because you can't distill card performance down to a single number.
Just because one card can support a certain sustained write speed with some host writing a certain way doesn't mean it will perform that way in the BMPCC the way the BMPCC writes to it.
If you want a rule of thumb, it's simple: buy SanDisk Extreme Pro cards from authorized SanDisk resellers. Time and again these cards have been shown to be better performers and more reliable than other brands.
This discussion has become about why most cards are dropping frames with the Pocket, not about which card is best, we all know the Sandisks are top of the line but when I have a card that can record 227Mbps in a Canon with Magic Lantern without dropping frames but that same card and a 172Mbps video is dropping frames on the Pocket, that points to a flaw in Blackmagic's design. We are just trying to find more information as to why this is happening so we can gauge if it will be fixed with firmware or if it's a major hardware issue that requires a hardware refresh :/
Rafael Molina wrote:One should know that there are a number of different transfer modes or transfer protocols used in sd-cards, e.g. using 1-bit or 4-bit serial transfers at different clock speeds. Not all controllers (in the card and/or the reader/writer) support all transer modes equally well. It really is the _combination_ of card and reader
Could you be a little more specific and expand on that? Are you saying that Blackmagic may have designed its controller to only support a transfer mode used in the top end Sandisks? I've read that Sandisk is using 3-bit multi level cell NANDs in 128Gbit(16GB) sizes, if that's true they would need a few more NANDs in their 64GB and 128GB cards which supposedly helps to increase random IO speeds and could explain why the 32GB Sandisk Extreme Pros were not approved.
Craig Seeman wrote:I've mentioned it before and it's exactly the same experience when the Sony EX1 started to use SD cards, It's not simply the speed of the card but, apparently, the controller built into the card. Some work better than others. Sandisk also worked unusually well with the EX cameras.
That's because Sony was working with Sandisk on the EX1's SxS media, so when they started adapting SD cards to the SxS port it was no surprise when Sandisk worked the best in an interface they helped design but at least they weren't the only cards that worked, other brand's faster cards still worked with the EX1. Why this would be happening again with Blackmagic and a standard SD card slot is the question.
Craig Seeman wrote:stick to the list - or forget the list and buy Sandisk SSDs and cards - I use them in the Pocket and the BMCs
I think some of us just can't throw money at problems without knowing precisely why.
Craig Seeman wrote:that write speed is perfect for marketing - bigger numbers always sale better and the average Joe Shmuck will never come close to them anyway, with his point and shoot box.
Actually we were talking about benchmark test results here but thanks for your thoughts about the average Joe Schmuck and marketing...