Which DT swiss hubs are they?
Regarding rims,317s are OK but 717s would be about 40g per rim lighter,and something like Stans 355 lighter again.
So a bit to be saved at the rims,but not much,hubs you may save more but need to know what you have now.
As said above what tyres are you running? Many 2.1s are 600-700g each.Swapping to soemething like a Nobby Nic or Maxxis Aspen might save you 100g or more each end,if you can live with them,and a much cheaper way to lose significant rotating mass.