What does it mean?
It means the DAG isn't being created as a file on your HDD anymore. Instead, it's being created by GPU, and stored in memory directly. There's a post not long after he released the version which made that change, where he explains exactly that.
this can make you mine even with 1GB system ram now?
No. dag is the secret sauce ethereum runs on. It grows a little bigger from time to time. Claymore moved it off computer storage and directly into the GPU- we all still have it but now it creates faster when needed and doesnt take up space in your hdd or ssd. 1gb graphic cards still cant run because they are still using the same dag, just generated directly to them instead of read from the pc somewhere.
It is not the GPU memory I'm referring to..it is the system memory..
in windows 64bit, before claymore made this miner..you can't mine with 1gb or 2gb system ram.