Is that really true? I mean the ETH DAG is bigger than 2GB now but I never felt that! Here are 2 case studies:

1. Seven months back I was new to mining ETH so I started with MinerGate as it was the easiest to start with. At the first day of my mining I noticed that after a full night (around 7 hours) of mining I spent only around 50 MB of data! Yeah, the mining started and I earned some ETH too! So clearly I mined without even downloading the full DAG. (Maybe a DAG Epoch?)
Interestingly enough, I even mined eth with MG on my laptop that has maybe 256 MB of graphics card or less when the DAG was around 2GB!! How was that possible?

2. Same thing happened when a month later I first started to mine with Claymore on Nanopool. Just few MB used per day. Till date I use Claymore on NP 24/7 and never seen the miner to download the full DAG.

So do we really need a card with memory size bigger than that of the DAG?
I guess that might be true with solo mining which I didn't waste my time trying. Enlighten me...