Is a rack of Gridseed Orbs better at mining this than GPUs? The GPU rack might cost as much as a higher priced LTC ASIC.
Are Gridseeds better than GPU? Yes, however you will still pay more for electric than you can mine with those unless you have very very cheap (free) power. Gridseeds were the first Scrypt ASIC but since then more efficient machines have come out and replaced them.
Yes, but they are all over $500, aren't they?
Newer ASICS? Yes they are more expensive.
It depends on what your endgame is. If you are trying to make money by mining you'll need to buy the more expensive miners (or get free electric). If you just want to play and learn (at a profit LOSS) then gridseed are ok (as are GPUs or even CPUs).
Examples:
an average CPU is probably 40kh/s and uses 100 watts
a 7950 GPU gets about 600KH/s and uses 220 watts
a gridseed gets 330kh/s and uses 8 watts
a KNC titan gets 300MH/s and uses 1300 watts
using the current price of LTC and an electric cost of $0.10 these are what you could expect with each of the above:
CPU:
Expected Rewards Costs Net Profit
24 hours 0.00039023 LTC 0.00 USD 0.24 USD -0.24 USD
7 days 0.00273164 LTC 0.01 USD 1.68 USD -1.67 USD
30 days 0.01170703 LTC 0.05 USD 7.20 USD -7.15 USD
GPU:
Expected Rewards Costs Net Profit
24 hours 0.00585352 LTC 0.02 USD 0.53 USD -0.51 USD
7 days 0.04097461 LTC 0.16 USD 3.70 USD -3.54 USD
30 days 0.17560547 LTC 0.68 USD 15.84 USD -15.16 USD
Gridseed:
Expected Rewards Costs Net Profit
24 hours 0.00321943 LTC 0.01 USD 0.02 USD -0.01 USD
7 days 0.02253604 LTC 0.09 USD 0.13 USD -0.05 USD
30 days 0.09658301 LTC 0.37 USD 0.58 USD -0.20 USD
KNC Titan
Expected Rewards Costs Net Profit
24 hours 2.92675781 LTC 11.36 USD 3.12 USD 8.24 USD
7 days 20.48730469 LTC 79.49 USD 21.84 USD 57.65 USD
30 days 87.80273438 LTC 340.67 USD 93.60 USD 247.07 USD