On block 614,400 memory requirements of Autolykos2 will be increased. Miners are talking about “DAG size increase”, however, in case of Ergo this is not about a DAG, rather, a table.
Dear miner software developers, please check the following test vector for valid PoW solutions for height 614,400 (with low diff of 16,384):
"pk" : "03bedaee069ff4829500b3c07c4d5fe6b3ea3d3bf76c5c28c1d4dcdb1bed0ade0c",
"n" : "0000000000003105"
How much will the table increase by ?
By 5%, so will be about 2.03 GB, thus 3GB cards will still be in the game.
Ergo’s PoW is about finding 32 numbers in a big table, each of 31 bytes, such as hash of their sum is less than target (a variant of hard k-sum problem, where k = 32) . Table size is 67,108,864 (2^26) elements initially, which is about 2,013,265,920 bytes (roughly 2GB). Algorithm is trying to enforce storing the table in RAM (and currently miners are storing it fully). Starting from block #614,400 the table is being increased by 5% every 51,200 blocks (~71 days). Simple calculations show that 3 GB cards will be in the game for 9 epochs ( 2013265920 - Wolfram|Alpha+%281.05+%5E+n%29+%3C+3102410241024 )
a few of us made this a while back to help estimate table size over time…rough estimates, but hopefully still useful autolykos table size math