16GB is overkill for Pi-hole + Unbound.

Yes, it’s overkill. 8GB is already more than enough, and a bump to 16GB won’t reduce query latency one bit.

Pi-hole and Unbound together idle at maybe 200-300MB of RAM. Even under heavy use you’re not hitting 1GB. On that Atom x5-Z8350, the bottleneck is CPU and network latency, not memory. Throwing more RAM at DNS queries doesn’t speed up resolution — it just gives you empty DIMM slots and a lighter wallet.

That extra 8GB will sit unused, drawing a tiny bit more power for no gain. If you want faster DNS, look at your upstream resolver or your network’s round-trip time. If you’re just running Pi-hole and Unbound, save the money and spend it on something that actually matters — like a UPS or a faster SD card.

The Atom chip is the weak link here, not the RAM.