Downloading the blockchain is easy. A much bigger resource hog is verifying the blockchain.
+1
I recently had to sync a new wallet from scratch, so I used a forced connection to a single up-to-date node on the same LAN. At first it was flying - several tens of megs transferred per second - but gradually the sync got slower and slower (more transactions per block?). Towards the end it was spending a second or two to verify each block.