Does anyone have experience using two identical Type A cards writing ARWs simultaneously in the a1 II or similar?
I'm trying to understand what to expect in relative buffer clearance with the a7rVI when using two cards for ARWs at 30FPS vs. one card. If it is drastically slower then probably not worthwhile. Thanks.
If they are identical cards, I believe they will be written to at the same speed as a single card. At least it seams that way. Softening my response as I'm not 100% sure.
I'd like to revisit this for the a7RVI. The buffer is not so great, but I am looking at trying two cards in parallel if only 10% loss or something like that. As of now I have 2320GB of Type A, but all 6 cards are different sizes, speeds and brands, so not easy to test.
I wish Sony allowed Type B, I have tonnes of those.
AFAIK, each card slot has an independent controller. So two identical cards write at the same speed as a single card. I only use CFE in one slot for raw and SDXC in slot 2 for jpeg backups. Jpeg size/quality in the camera is scaled to the SD card write speed. If my SD card writes at 1/4 the speed of the CFE, I use whatever jpeg is 1/4 the size of the raw. Then the SD card isn't a bottleneck. The CFE slots seem to only use v2 controllers and max out at ~800MB/s. I don't think any cameras actually have v4 controllers.
You can get a usable number even with mismatched cards. As far as I understand it, with simultaneous recording a frame only leaves the buffer once both cards have it, so the pair can't clear faster than the slower card on its own.
So: take the slower of your two best cards as the baseline. Same scene, same settings, a fixed 5 s burst at 30 fps, then time from the last frame until the access lamp goes out. Do that three times with the slower card alone, then three times with both slots set to simultaneous. The gap between the two averages is what dual writing actually costs you on that body. If it's close to zero, you're only limited by the slow card, and a faster matched pair later would just move both numbers down.
