In your experience what's the sort of time for finding a block at that speed? Are we talking days/weeks/months.......?
Thanks
Are you asking about how long you would expect 7TH/s to find a block solo mining? If yes, that's easy to calculate:
43971662056 * 2^32 / 7000000000000 / 86400 = number of days expected to find a block. So, 312.26 days at current difficulty.
If you're asking about p2pool, that's a whole different question. You get paid for every valid share you have on the chain when p2pool finds a valid block.
Using the same formula, you can calculate expected time to find a share...
10616061.28 * 2^32 / 7000000000000 / 86400 = 0.075 days = 1.81 hours. So, you would expect to find about 13 shares a day. Shares are weighted depending on network difficulty when found, and those weights are used to determine your payout when the block is found. Realize that the share difficulty retargets constantly depending on perceived network hash rate, as does the expected time to block.