1000 txs/sec might be referencing the total of transactions happening on the Tangle.

The number of txs/sec a Node receives depends on three things: how many light nodes are connected (and submiting transactions) to it, how many transactions it is receing from its neighbors and its download bandwidth. So we can see that it's a value that changes from Node to Node depending on its specs. The number of txs/sec a Node can push to the Tangle depends on its upload bandwidth.