The size of the memory is not playing seems to be no difference between
You need to set HashCnt > 512 to see the difference, but you cannot do it because of 1GB. Therefore, no speedup for 1GB cards.
I tried to 2Gb cards all possible values of the parameter h. And compared with 1Gb cards only in the negative (or 0 difference)
20:22:58:140 e20 parse packet: 303
20:22:58:148 e20 new buf size: 0
20:22:58:173 e20 Pool Diff 10000
20:22:58:178 e20 df has same pool, skip
20:22:58:283 da0 Round
20:22:58:302 2ec Round
20:23:00:605 c08 GPU 1: HashCnt = 448, time = 2258 ms, hashrate = 198 h/s
20:23:00:619 da0 GPU 0: HashCnt = 448, time = 2228 ms, hashrate = 201 h/s
20:23:00:628 c08 Round
20:23:00:639 da0 Round
20:23:00:651 f60 GPU 3: HashCnt = 448, time = 2265 ms, hashrate = 197 h/s
20:23:00:661 f60 Round
20:23:02:441 cd8 GPU 2: HashCnt = 768, time = 4047 ms, hashrate = 189 h/s
20:23:02:470 cd8 Round
20:23:02:617 77c GPU 4: HashCnt = 800, time = 4200 ms, hashrate = 190 h/s
20:23:02:650 77c Round
20:23:02:825 4d0 GPU 1: HashCnt = 448, time = 2166 ms, hashrate = 206 h/s
20:23:02:848 4d0 Round
20:23:02:864 ee4 Round
20:23:02:907 2ec GPU 3: HashCnt = 448, time = 2206 ms, hashrate = 203 h/s
20:23:02:919 2ec Round