DRAM-less is fine for the deck. Playing games is mostly large reads and small writes for saves. When writing you're likely downloading which is going to be the slowest link in the chain. As you saw with this external drive, it could write quickly for 30GB. Getting bigger for less money is gonna be worth it, especially with the limited physical size of a 2230.

The key metric is game load times, which don't change much even for desktop systems on drives that read 400MB/s or 5GB/s. So don't worry about it too much.