I have performance issue on 0.6.1 as well :
0.6.0 :
2018-05-16 08:29:40| GPU2 55C Sol/s: 433.5 Sol/W: 3.65 Avg: 437.7 I/s: 236.2 Sh: 0.90 1.00 71
2018-05-16 08:29:40| GPU0 52C Sol/s: 453.7 Sol/W: 3.77 Avg: 449.3 I/s: 237.7 Sh: 1.50 1.00 71 +
2018-05-16 08:29:41| GPU1 49C Sol/s: 445.0 Sol/W: 3.69 Avg: 441.4 I/s: 237.4 Sh: 2.39 1.00 71 ++
2018-05-16 08:29:42| GPU3 45C Sol/s: 452.8 Sol/W: 3.71 Avg: 445.3 I/s: 238.6 Sh: 1.19 1.00 71
2018-05-16 08:29:43| GPU4 50C Sol/s: 471.4 Sol/W: 3.87 Avg: 462.9 I/s: 248.3 Sh: 3.28 1.00 72
2018-05-16 08:29:45| GPU5 51C Sol/s: 466.2 Sol/W: 3.89 Avg: 464.1 I/s: 247.8 Sh: 2.39 1.00 71 +
2018-05-16 08:29:47| GPU6 48C Sol/s: 461.2 Sol/W: 3.87 Avg: 461.4 I/s: 245.9 Sh: 2.09 1.00 71 +
2018-05-16 08:29:47| ========== Sol/s: 3183.7 Sol/W: 3.78 Avg: 3162.2 I/s: 1691.9 Sh: 13.74 1.00 71
0.6.1 :
2018-05-16 08:32:46| GPU0 50C 50% | 206.1 Sol/s 211.9 Avg 110.3 I/s | 2.01 S/W 107 W | 0.00 . .
2018-05-16 08:32:46| GPU1 48C 50% | 417.7 Sol/s 422.9 Avg 226.7 I/s | 3.51 S/W 121 W | 1.71 100 71
2018-05-16 08:32:46| GPU2 47C 50% | 162.1 Sol/s 171.1 Avg 89.3 I/s | 1.73 S/W 93 W | 1.29 100 72
2018-05-16 08:32:46| GPU3 44C 50% | 431.6 Sol/s 429.5 Avg 227.9 I/s | 3.56 S/W 122 W | 3.41 100 278 ++
2018-05-16 08:32:46| GPU4 44C 50% | 158.6 Sol/s 159.4 Avg 82.8 I/s | 1.80 S/W 83 W | 0.48 100 71
2018-05-16 08:32:46| GPU5 50C 50% | 437.5 Sol/s 440.9 Avg 234.4 I/s | 3.66 S/W 120 W | 2.34 100 71 +
2018-05-16 08:32:47| GPU6 44C 50% | 198.9 Sol/s 204.0 Avg 107.9 I/s | 1.93 S/W 111 W | 1.70 100 70
2018-05-16 08:32:47| ============== | 2012.5 Sol/s 2039.8 Avg 1079.3 I/s | 2.60 S/W 760 W | 10.93 100 105
the config is 7 * msi gaming 1070 on ubuntu 18.04, nvidia drive 390.48