Is your problem fixed yet?
If not, check this:
1. Did you have latest driver for NVIDIA?
2. Did you have lot of program that are running in background?
3. Did you enable V-Sync or frame limiter on the game?
4. Check for CPU throttling.
5. Reset game configuration by deleting CFG file, and let the game build a new one.
4. Try to disable windows 10 "compressed memory"? It's problematic for some users and consume CPU usage. especially if you have more than 4GB of RAM.
If it only happens only to both games that you're trying to play, it means that the game is badly optimized or coded.
there are lot of i7s, which i7 you have? h81 chipset means, I hope it is LGA1150 socket, it is 4th gen i7 but again i7 K version or simple i7-4790?
As per you CPU temperature, 40-45C appears absolutely fine, it means CPU is not running at full percentage, it it runs at full utilization, temp should reach 65-75C, I hope it is not bottlenecking, we need to drill down to find the root cause
BTW GTX 1050TI cannot even bottleneck i3, cos GTX 1050 is slightly better than the GTX 750 TI
H81 means: Intel 4th gen PCH or chipset on motherboard. And I bet that the OP have Intel Haswell 4th gen CPU without K SKU, since H81 doesn't support overclocking, there's no point to get I7 4xx0K CPU except he wants to future proof his PC by buying B or Z series chipset later.
And it doesn't need to reach 65-75C to run at full utilization if you have good thermal solution like AIO cooler or huge heatsink.
Who said if i3 can't bottleneck 1050ti? If the game is more CPU dependent, then most likely is.
remember that i3 is only a 2c and 4t CPU.
And 1050ti is waaay more better than 750ti and comparable to GTX 960 2GB.