Unfortunately, the best hope right now is that Alpha Technologies will manage to ship their ASICs by the end of September, which is still nearly two months away. Their competition in the meantime continues to grow, the difficulty of mining Scrypt coins likewise continues to increase, and there's a real question on whether or not you can make a decent profit on the venture. As a point of reference, the difficulty of Litecoin mining has nearly tripled in the past two months; if that happens again, the chance of breaking even on an Alpha Technologies ASIC is going to drop quite severely (though it's more likely we'll see difficulty start to stabilize before it becomes unprofitable).
The good news is that the current specs for the Viper and mini-Viper are still quite promising, assuming of course that Alpha Technologies can deliver. If you run the numbers the Viper will do 1MH per 7.5W; doing the same 1MH with a GPU would require at least 300W in my experience, so that's a great improvement in efficiency. There's more good news as well: KnC's Titan miner is still not yet shipping, and considering their Neptune (which was available for pre-order about a year ago) has only recently shipped it might be 4-6 months before any Titan ASICs are running.
The problem is that while these two behemoth Scypt ASICs are still trying to reach production, other companies are not standing still. I've mentioned various alternative Scrypt ASICs in the past, but the estimated ROI for buying any of them was at best four months, which means six months ROI is more likely. And if difficulty skyrockets in the interim, you might only break even or come out with a 10% gain. That's not bad as far as investments go, but the risk of a pre-order is still huge so the reward should be commensurate.
There are of course other alternatives for buying mining hardware. One of the most popular places to go for Scrypt ASICs (or Bitcoin ASICs, even) is GAW Miners. One of the features that sets GAW apart from other operations is that they now support cloud-hosted mining, which isn't necessarily all that remarkable until you see their pricing for the hosting service. Many cloud mining services charge you so much that it's virtually impossible to hit ROI, but I've run the numbers for GAW's cloud-mining and they're basically charging what I already pay for electricity (around $0.10 per kWh).
Bitmain Antminer S3 Bitcoin ASIC. It will cost you $500, you'll be up and running within 24 hours, you get one month of free cloud mining, and after the month is up you only pay $0.90 per day. Considering the ASIC is using 366W according to the specs, that works out to 8.8 kWh per day, which means I'd be paying $0.88 per day to have that at my home. Now add on the fact that you get to remove that noise and heat source from your home (which is a major problem for me during the summer months) and it's basically a no-brainer. Of course, an Antminer S3 isn't the most profitable option right now, as it's less than 0.5TH. It earns around $6 per day, which means you could hit ROI in about three months (probably four with difficulty increases).
If that's not the best option right now, then what is? Assuming you don't want to fool around with pre-orders (the 4.5TH Spondoolies BTC ASIC for $3900 is supposed to ship in September if you're okay with pre-orders -- ROI estimate on that one is about two or three months right now), my pick would be one of the Zeusminer Scrypt ASICs. Wait, aren't those supposed to be some of the least power efficient Scrypt ASICs? Well, yes, but they're also substantially cheaper than the competition. The model I'd specifically recommend is the Lightning X6 40-42MH ASIC, currently priced at $800.
I do wish I could have jumped on their Vaultbreaker offer, but with money tied up in Alpha Technologies I had to sit that one out. 500MH for $7000 on 1500W is crazy to think about, and now it's been bumped to 750MH! If GAW manages to deliver on their promise of beating KnC's Titan to market -- "Scrypt Mining is my house, and I will not be beat in my own house!" -- well, KnC might have a few (more) unhappy pre-orders on their hands. Personally, I'm just going to take a wait and see approach. A lot of major promises have been made -- and broken -- by the ASIC companies, but GAW seems to be on a roll right now. Let's hope for the sake of my Lightning X6 ASICs that they continue.
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