Consider your current system and needs before choosing an upgrade.
Consider your current system and needs before choosing an upgrade.
To connect a graphics card, you need Thunderbolt. USB isn't suitable—it usually has only a couple of ports, all linked to the same controller. I won’t dwell on the differences between USB, PCIe, Thunderbolt and their standards. Those issues can’t be fixed with custom software. I’d advise against trying to upgrade it yourself; it’s like trying to fix a broken balloon with patches. Sure, it might keep holding air, but a proper solution would be a better, new balloon. You’re better off getting a used PC and upgrading it instead.
I recommend upgrading to a CPU paired with a GTX960 or RX 550, which frees the integrated graphics from workload. These options are roughly around 100USD new, potentially cheaper on eBay if you search quickly. This should improve Minecraft performance at reasonable settings. Don’t forget to check for driver updates for the 620 Integrated graphics, and be aware the 6500T may no longer receive support—consider the latest available driver instead.