I have an experimental rig asus prime z-370A + i3-8100
If you include 3 1050ti cards through risers into 3 GEN3 slots (3 16x - GEN3), you get the result: 150, 150, 250, if you connect 2 cards to GEN3, and third in PIC-E 1x, you get 150, 250, 250.

0-290.1 1-233.5 Total: 523.7 H/s  2018/06/03 20:20:03 1 - Yay, solution found!
0-309.1 1-245.0 Total: 554.0 H/s  2018/06/03 20:21:11 1 - Yay, solution found! - 2x1050ti Intel(R) Pentium(R) CPU G4400 @ 3.30GHz PCI-E 16x GEN3 without raisers

It is necessary to include PCI-E GEN3 everywhere. In the rig with the i3 8400, this changes the speed from 700 to 1000-1100. On the rig with the g4400 processor nothing has changed and the card 1050 gives still 150 h / s. The CPU load is 100% on all rigs and more than 1000 h / s with 1 rig is not obtained. Pentium g4400 it does not work out more than 700-800.

You can put at least as many cards as you like, but you can not get 1000-1200 hashes from 1 rig.

 0 01:00.0 GeForce GTX 1050 Ti (4039 MiB, 95.00 W)
 1 02:00.0 GeForce GTX 1050 Ti (4040 MiB, 75.00 W)
 2 06:00.0 GeForce GTX 1070 (8119 MiB, 200.00 W)
 3 07:00.0 GeForce GTX 1050 Ti (4040 MiB, 75.00 W)
 4 08:00.0 GeForce GTX 1050 Ti (4040 MiB, 75.00 W)

0-279.4 1-252.3 2-193.8 3-193.5 4-190.0 Total: 1109.0 H/s  2018/06/03 02:15:25 2 - Yay, solution found!

1070 - card number 3. And why 1 and 2 cards are approximately equal, when the system only 1 1070 and 4 1050?

NVIDIA-SMI 381.22   

I get different results depending on the operating system and drivers.
Gentoo, 1050ti@PCI-E 16x, AMD Phenom 2, 16gb
CUDA = 8
Driver = 381 , CARD COUNT=1 , WK=0x254
getGpuCount error:0

Init GPU Device 0: "GeForce GTX 1050 Ti" with compute capability 6.1

2018/06/02 20:20:33 Starting BTM mining
2018/06/02 20:20:33 0 - Initializing
2018/06/02 20:20:33 0 - No work ready
2018/06/02 20:20:35 login of bm1q6gt9njdkrr7tg0jlghwykrw8jj5sz7ckjnjxv3.0x254 success
2018/06/02 20:20:35 waitting ...
2018/06/02 20:20:35 New job received from stratum server
2018/06/02 20:20:36 0 - Continuing
Update seed cache on device 0
0-238.3 Total: 238.3 H/s  2018/06/02 20:20:39 New job received from stratum server
0-237.5 Total: 237.5 H/s  2018/06/02 20:20:58 0 - Yay, solution found!
0-237.7 Total: 237.7 H/s  2018/06/02 20:21:56 0 - Yay, solution found!
0-235.6 Total: 235.6 H/s  2018/06/02 20:22:19 New job received from stratum server
Update seed cache on device 0
0-236.3 Total: 236.3 H/s  2018/06/02 20:25:25 0 - Yay, solution found!
0-236.9 Total: 236.9 H/s

HiveOS, CUDA9 1070 PCI-E 16x, 3x1050ti PCI-E 1x i5-4590 CPU @ 3.30GHz, 32Gb:
0-307.7 1-274.9 2-200.5 3-197.8 Total: 981.0 H/s  2018/06/02 20:27:15 0 - Yay, solution found!
0-299.9 1-277.6 2-198.1 3-195.5 Total: 971.1 H/s  2018/06/02 20:27:21 New job received from stratum server
0-305.8 1-271.0 2-195.4 3-198.0 Total: 970.3 H/s  2018/06/02 20:29:10 0 - Yay, solution found!
I can not even figure out which of the cards is 1070 (
Very strange miner.