You have to first identify and ensure the two devices and their ports are capable of reliably creating and absorbing that data rate too or you'll never know if it's the cable or the devices that causes the cables to fail. What if your devices can but only intermittently or a software/firmware update messes with it's capabilities?

Dedicated test equipment that can reliably and verifiably test these high speeds is niche and therefor expensive. There's not really a way around that issue.