I am grateful for all the people like you who have gone out of their way to help me understand crypto currency better and to mine them. I have done quite a bit of research into the altcoins and know which ones i agree with and think will succeed. Ive come across a few people who tell me i lack the hardware to mine any coins. I am wondering if you share that opinion?
Another question I have is what exactly do you mean by putting 50 in both SHA-256 MH/s field and scrypt KH/s field? On my macminer and under miner settings i see next to scrpyt says thread concurrency and wondered if I was supposed to type 50 there and couldnt figure out where to put the 50 with SHA-256..
Oh no! Sorry, I meant on the Coinwarz website profitability calculator. 50MH/s is a rough guess at how fast your video card will solve SHA-256 and 50KH/s is a rough guess of how fast it will solve scrypt. I didn't mean those numbers should go in MacMiner. Sorry for any miscommunication.
As far as whether you have the hardware to mine "any" coins, well, that coinwarz calculator will give you an estimate of what to expect. So you can probably mine about a half dozen DGC per day, or 100 SBC, or two days for one PPC, four days to get one TRC, or four months for one Bitcoin. Therein lies the value of pooled mining: you don't have to wait for a whole block, you can get your payments in a variety of intervals. Do pay attention to the minimum payout thresholds of mining pools—they vary.
So do you have the hardware to participate and do a small part in a grand distributed computing financial movement? Hell yeah! That's what the "distributed" part means. Do you have the hardware to raise enough money to be worth spending? In a couple weeks you might raise fare to ride the streetcar—and you might spend more than that in electricity. It's not about what you "can" or "can't" do—you should just have realistic expectations.
My (again, unsolicited) advice is to give it a whirl. If in a week you see the window open on your computer and think, "oh, is that still running? what was I thinking?" you can turn it off. If you spend the entire week excitedly checking your hashrates and voraciously trying to learn more, then maybe invest (I use the term loosely) in something that will do more than your current setup, and give your Mac a well-deserved rest. And of course there are many possibilities in between those options.
Don't let gweedo's attitude scare you off, but do be mindful of what he said about melting your GPU. smcFanControl is your friend, and start with lower intensities. When I mined on my GPU I didn't burn anything but it did make my computer sluggish and really difficult to use if the intensity was over 5. Your mileage may of course vary.