AMD HD 6670 1GB, test using AMD Catalyst 13.12, Windows 8 x64, G1610 CPU:
1. ominer 0.8, 425 cpm, fixed to upcpu, pool fee 2%, net performance user gets: 417 cpm;
2. PtsGPUz 0.4c, 380 cpm, pool fee 3% at ptspool.com, net performance user gets: 368 cpm;
3. ominer 0.9 preview 2, 336 cpm, fixed to upcpu, pool fee 2%, net performance user gets: 329 cpm;
4. clpts 0.2.2, 218 cpm, fixed to ypool.net, miner fee 5%, pool fee 5%, net performance user gets: 197 cpm.
Note: clpts 0.2.2 seem to be the fastest on AMD cards with 2GB or more video memory, but slowest on cards with 1GB memory.