Thank you for the tutorial, I also want to build my own one. But correct me if I’m wrong:

You want to support 2 graphic cards (on your motherboard), it requires you 16 PCI-e lanes each. But the i5 CPU you selected only supports “Max # of PCI Express Lanes 16” (from provided link https://ark.intel.com/products/97123/Intel-Core-i5-7500-Processor-6M-Cache-up-to-3_80-GHz) I guess you will not get full performance while training with multiple cards.

BTW, after spending some time playing with GPUs I have learned that feeding the GPU with data is one of the main bottlenecks that I have found, so thinking about upgrading the CPU seems to be a good idea.