EWBF 0.3.4b:
GPU0: 454 Sol/s GPU1: 672 Sol/s GPU2: 687 Sol/s GPU3: 679 Sol/s
Total speed: 2492 Sol/s
+-----+-------------+--------------+
| GPU | Power usage | Efficiency |
+-----+-------------+--------------+
| 0 | 153W | 2.97 Sol/W |
| 1 | 203W | 3.31 Sol/W |
| 2 | 198W | 3.47 Sol/W |
| 3 | 201W | 3.38 Sol/W |
+-----+-------------+--------------+
yours:
> GPU0 Sol/s: 454.4 Avg: 454.4 I/s: 240.1 Shares/s: 0.000
> GPU1 Sol/s: 684.6 Avg: 684.6 I/s: 365.5 Shares/s: 0.000
> GPU2 Sol/s: 683.4 Avg: 683.4 I/s: 367.8 Shares/s: 0.200 ++
> GPU3 Sol/s: 686.0 Avg: 686.0 I/s: 365.4 Shares/s: 0.000
==== Sol/s: 2508.5 Avg: 2508.5 I/s: 1338.9 Shares/s: 0.000
2492 Sol/s vs 2508.5 .. hahah . is no difference

) dstm's ZCash Cuda miner is the fastest zcash miner!
waiting windows verson, and fee 1% (today 2%)
That is just 1% difference. So it is comparable.