Thanks. I've just looked over DS and 3DS game card sizes to try to find when each size was first used, although it's tricky to find reliable sources on these things, and I've updated the graph:
For the trend line I've just used the size of launch games for each device, as I feel that's the most appropriate for our current discussion. (A game like Ni No Kuni releasing in 2010 probably wasn't pushing the boundaries of technology at the time, considering 2GB 3DS games arrived just two months later). I've also seen other claims that Ni No Kuni was actually a 256MB game card, and it seems Rub Rabbits was the first 128MB, so I honestly can't be 100% certain on anything other than the launch games anyway.
Here's the data, in case anyone has any corrections:
Code:
Release MB
Various 16/11/04 32
Meteos 10/03/05 64
Rub Rabbits 20/10/05 128
ASH 04/10/07 256
Ni no Kuni 09/12/10 512
SSF:IV 26/02/11 2048
RE:R 26/01/12 4096