HD 6850 should work - it won't be real efficient (nothing Terrascale works as well on ZCash mining as the newer GCN cards) but it SHOULD work.

 I did some testing on the GPU side of one of my A10-5700s a while back (which is ALSO Terrascale) and it mined - a whopping 11 or 12 sol/s compared to my 7750s that do about 50 (same number of cores and core clock, much slower memory for the A10, 7750 IS GCN).



 I seriously doubt 95% of ZEC mining is on Claymore - there are too many VERY competative alternatives.

Yes, unless you're willing to pay a CRAZY markup on the L3+, the best way is normally to go though Bitmain direcly - when they're in stock, like the S9/T9/R4 it would appear that BitMain has issues with not having access to enough foundry capasity to be able to get all the chips they want so they spend a lot of time "out of stock".

 ZEC is not particularly impressed with memory speed - it wants raw CPU quite a bit more, so bump core clocks up and memory clocks flat or DOWN a little for best results IME.

 It also depends a LOT on the specific card model, especially when you look at cards like my Gigabytes that have a FACTORY TDP of 180 watts (vs 154 or 155 for "1070 standard") and a high factory overclock.

 TDP as a percentage is MEANINGLESS unless you specify the actual card.

Always trust the "at the wall" measurements made with a real power meter over any software solution.

 It won't be that limited - most ETH is being mined by AMD cards, but those cards also work well on quite a few other algos.
 I expect to see probably the majority of those cards switch to ZEC, with a scattering to other algo coins like XMR that AMD cards are good on.

 I figure most of the NVidia cards on ETH (probably not very many, it's NOT even close to being the highest profit coins for most NVidia cards to mine) will move to ZEC, and a few to "all over".

If you are looking for max income from min power, take a good look at the Baikal ASIC miners.

The Bitmain Antminer L3+ is another option to take a hard look at.

Or go my route and build 3-card rigs with no risers and still have the spacing for good cooling - and they're not much IF ANY MORE per GPU than riser rigs while being noticeably easier to set up, get working, and tend to be more reliable.

 Mining generally does NOT need PCI-E 3.0 for full speed performance, as it's not bandwidth-heavy to the GPU in most cases - so going a lower-cost AMD route on the AM3/AM3+ socket and DDR3 (which is STILL cheaper at the low end than Intel's needed DDR4, though the price gap IS finally narrowing) is very viable.

I usually mine for "now" (defined as "I'll be selling it today or tomorrow) as I have bills to pay and usually have spare power capacity available to set up more miner rigs to use.

On RARE occasions when I have excess I might hang on to a few mined coins for up to a couple months when I think that coin is going to appreciate for a while (right now LiteCoin) *AND* I don't have enough spare coin to build a new riig yet.


 Last couple months have been different though - my power capasity where I'm at now is capped, and I've been in negotiations for a new place (then availability got delayed when the existing tenant took a month longer to get moved out than the landlord was anticipating) so I had to save up cash for first-and-deposit while keeping enough around to keep the current place paid up....

 Not only no but HELL NO.

 Laptops aren't designed to run at high load levels (like mining puts on them) and WILL overheat and often die if you try unless you take extreme measures to try to cool them that kill your profitability - and sometimes THAT isn't enough.

 Running a USB miner on a laptop isn't a big deal - the software doesn't put much load on the laptop as almost all the actual WORK of mining is being run on the USB-connected device.


 You should be able to run 4 x GTX 1070 comfortably on a Seasonic X-1050 - I run 3 on the X-850 with plenty of headroom - but I'd like to know where you are finding those now, NewEgg has been out for a week or so and Seasonic appears to have discontinued production on them in favor of that "Prime" series with the JUNK fan.

 EVGA G2 series would be my second choice - the G3 ALSO went to a junk fan and should be avoided.

 SSD on a mining rig is overkill, you don't need the extra speed - but the low-end ones are cheap enough they might be price-effective, since you don't need 500 GB on a mining rig as a general rule (BURST/STORJ/MAID is a different story).


 X11 is a bad choice to try to mine with a GPU - there are 3 different companies that have made ASIC miners for that algo ALL of which are a ton more efficient than any GPU.
 Scrypt (Litecoin, DOGE, etc) is a worse choice, as the ASIC for that algo are into at least their 3'd generation, each of which has gotten more efficient, and the FIRST ASIC generation was a lot more efficient than any GPU.
 SHA256 (Bitcoin etc) .... even worse than Scrypt by a wide margin, don't even bother THINKING about that with anything but a recent generation ASIC AND cheap power.

 Don't forget to allow about 20% derating on that "20 amps" for continuous usage, especially in the summer and ALLOW MORE if your breaker box is not in A/C in the summer.

 The capacity of a breaker is normally rated at 40C - that's only 102 F, and you have to factor in the breakers NEXT to it also getting warm, the box retains some heat, and that 20 amps is an "intermittant service" rating NOT a 24/7 continuous duty rating.

 Last summer when I was still in Iowa, I didn't use AC in most of my place (including where the breaker boxes were at), and with the temps hitting 100+ in the shade on a few days there were times that my 15A breakers were tripping with SLIGHTLY LESS THAN 10A OF LOAD on the circuit - on BRAND NEW QO breakers.

 Part of my issue was I was using those "2 breakers in one housing" breakers on a couple circuits - those need to be heat-derated a LOT more - but even the single-per-housing breakers would trip if I put 12A of load on their circuit for more than a few minutes.

 1070 doesn't do 480 sol - more like 450 if you push it or get VERY lucky in the memory sweepstakes, and 400-420 if you tweek it for more EFFICIENT mining.
 It's still VERY profitable at this point though on quite a few coin options - as are ANY current-generation card.
 
 AMD ROI has been getting hammered the last week, as the RX 4xx cards run out FAST and are getting price-jacked bigtime on the few remainders, while the RX 5xx haven't had their production ramped up enough yet to make up the shortfall and are ALSO getting priced at a premium as a result.

 Newegg doesn't have that crazy-low deal on the Zotac mini running any more, but they commonly have at least ONE decent 1070 model on sale at 379 and usually a few to choose from.


 If you want WIDE price and network hashrate variations, look at the smaller cap coins like DGB and GAME and such. 50% bounce in profitability from one block to the next is COMMON down there.

Be afraid.

Be very afraid.

 I just specified parts and priced out the first Intel-based rig I will have ever built since the Pentium 4 days (and THAT one-and-only rig was the first Intel rig I'd built since the Pentium MMX days, though I did end up with a pair of Pentium Pro systems at one point that quickly got upgraded to Athlon Thunderbird setups - the CASES were nice and cheap despite being "full systems").

 Up side - all PCI-E 3.x 16x ports for the GPUs, should help them when I send the rig Folding someday.
 Down side - I'm estimating half the performance out of the IGP on my Moo Wrapper/BOINC/RC5-72 work vs my usual AMD A10-7860 despite the Intel APU being almost the identical price.

 Tossup - MB + RAM + CPU ended up being almost identical cost to my usual choices, which I was a bit shocked at - Gigabyte has a sweet deal going for a NON-SALE price on the MB, quite a bit lower then the next-cheapest 3-card capable Intel motherboard I've seen for socket 1151, and DDR 4 at the low speeds has come down to where it's actually competative with DDR3 on pricing.


 Dunno if this is going to turn out to be ANOTHER one-shot setup - it all comes down to how well it does on Folding PPD vs my usual setups, though I expect it to be a tossup for mining as mining algos aren't generally PCI-E throughput-heavy like Folding is.


 I also noticed that the supplies of the RX 470/480 are pretty much all gone - and what's left is getting price gouged BADLY as AMD hasn't gotten RX 570/580 production up to full speed yet, thus THOSE cards are still going for a small premium to their intended "list" price range.
 I had ORIGINALLY intended to spec/price out a 4x card system using the Biostar Racing motherboard or a close equivilent, but no way am I going to try to space 4x 1070s (not Katanas as those have been "out of stock" longer than I've known about them) much less 1080s or 1080TIs that closely together.


 I still haven't decided between 2 x 1080 + 1 Gigabyte "ITX" 1070 or 2 x full-length 1070 plus the Gigabyte though.

64 isn't all that bad a temp on a modern GPU - but it does indicate a warm ambient temp OR you're not getting enough airflow TO the cards for them to cool properly.

 Part of it is comparing the current NVidia "started at the HIGH end of the lineup and working it's way DOWN into the mainstream" vs AMD "start at the mainstream and work it's way both up AND down from there" - with AMD not releasing it's first high-end cards 'till this June with the first VEGA cards.

 As I recall, the best cards AMD has at this point on ZEC are the old Fury/FuryX/Nano series (and the Pro Duo, which is basically a pair of Nano on one physical card) - which are a full generation behind the RX series on process node and tech and suffer as a result.

 Based on the "preliminary" and "estimated" specs I've seen about the "Vega Frontier" (same core count as the Nano/FuryX but clocks 50% or more higher), the Vega cards should at least be able to argue well vs. the GTX 1080 and likely the GTX 1080Ti on ZEC hashrates.


 Right now though, the only FAIR "same market segment and pricing" competition is the GTX 1060 varients vs the RX 470/480/570/580 (the 1050Ti / RX 460 and down don't do enough hash to justify buying them JUST for mining with).
 That's pretty close when you factor in that the 1060 clocks quite a bit higher but has a MUCH lower core count - enough so to indicate that the ZEC algo works a little better on NVidia architecture *OR* the NVidia code in current miners is a little more efficient *OR* a bit of both.

I VERY strongly recommend sticking with the NEC and using NEMA 6 plugs/jacks on any 220V circuit in the USA.

 Cords are not hard to find - plenty of sources for NEMA 6-15 or NEMA 6-20 to C-series cords on Amazon, and Newegg has a few.
 They DO tend to cost more than the VERY common NEMA 5-15 to C-series cord most power supplies and computers sold in the US are supplied with, due to how uncommonly used they are in comparison.

 As I recall, a 6-15P  WILL plug into a 6-20R or 6-30R, but a 6-20P won't plug into a 6-15R and a 6-30P won't plug into a 6-15R or a 6-20R due to how the contacts are orientated (an in the case of the 6-30 I believe the contacts are are longer as well).


 Most computer power supplies any more are auto-switching for any voltage from around 100 to around 240, but most OTHER items you might plug into a 220 outlet will die badly with a tendancy towards sparky fireworks and sometimes exploding capacitors if they are designed for 110.

 *ROFLMAOSC*

 A more realistic goal on CPU mining would be to achieve $2-3 dollars A DAY per CPU, and that is only possible due to the major price runup Monero has had the last few days and you need either a VERY high-end many-core CPU or a very recent high-end multi-core CPU to have a chance at that.
 Then you have to subtract the cost of the electric they use (14 core Xeons are quite power hungry as I recall).

 For reference, even with the recent MAJOR profitability increases in most coins, my highest-income rigs with 3 x GTX1070 GPUs pull in very close to $1/hour.

It also depends a lot on the brand of the memory on your specific 1070 - some just works better, which is critical for a memory-hard algo like ETH uses.

 I've NEVER seen a 1070 that could manage +1200 in afterburner (but I don't think any of the 1070 I have use Samsung - even my Gigabytes)
 With that said, bumping memory clock up as far as you can with reliability, bump power limit way down, and bump core clock down is the way to go on tweeking a 1070 for best ETH mining efficiency.

Looks like Caanan intends to go with GF or Samsung for their next gen then, as TSMC isn't going to be working on 7nm for a while and Intel uses all of their foundry space internally.

 R9 290 isn't a good ZEC choice anyway - they would be making more on ETH despite ZEC's recent price jump, abet not by a wide margin.

 In my recent testing of Claymore 12.4 on a pair of my R9 290 vs a pair of my R9 280x the 290s were just a very LITTLE faster on ZEC - but the 290 is right around DOUBLE the hashrate on ETH of a 280x.
 It would take a R9 290 being over 30% faster than the R9 280x on ZEC (400 sol/s vs 300 per card) to match the profitability of the R9 290 on ETH - but I was seeing less than 350 per card out of the R9 290s.

 Just to add insult to injury - my R9 290 have been bios modded via TheStilt, the R9 280x are pure stock.

 Better speed in miners actually DOES help some - for those that change over quickly.
 Some folks take a week to change, some have big enough farms it might NEED 2-3 weeks to get them switched over, some might only check once in a month on new stuff.

 It's not a significant help long-term though as folks WILL get moved to the newer faster stuff.

 I don't expect the pricing to burst soon - the movement of capitol into Crypto, coupled with increasing PUBLIC acceptance, seems likely to keep prices up for a while.

 I expect the PROFITABILITY bubble to burst when ETH goes mostly POS - but that's end of year at the earliest, and probably somewhat longer even if they DON'T have any more delays.