do i have to say this in every fucking thread? without litecoin and other altcoins, bitcoin mining would cease to be profitable. alt coins are necessary evils because they spread the hashing power out accross multiple networks, allowing everyone to profit in some way shape or form. without litecoin and altcoins. you could multiply the difficlut by 5 and decrease your profit by 50 percent. those are just guestimates of course.
No longer true in the ASICS era. The BTC network is approaching 20 TH. All the scrypt coin hash rates combined, if redirected to BTC, would only be about 2 TH.
With respect to BTC mining,
GPU's have become irrelevant