R9 290 4GB is a better way to go that the R9 3xx series, if you can find a 290 - less expensive but hashes just as well and ROCK SOLID reliability. Flashing them with a mining bios from TheStilt makes them VERY VERY nice.


 Building mining rigs using old parts might be less efficient, but it tends to be a TON less expen$ive and overall likely to SAVE you money. The HUGE majority of my GPU-based mining has been done with systems that were largely used parts or "already on hand", then added GPUs for the actual mining work - and a few were systems I already had on hand doing OTHER stuff that I just repurposed.


 The "fire hazard" statement is BULLSHIT.
 There is no reason for used parts to be more of a fire hazard than new, *IF* you have any clue at all about how to build a system in the first place.

 Probably designed specifically to power a pair of R4 units - 1 PCI-E per hashboard, 6 hashboards + controller seems likely.


 While the ORDER page links seem to have been dropped or changed (perhaps posted in error), the PRODUCT link to the "comming August 29" page IS still up and active. Looks pretty "official" to me.

Looks like they went to a long thin blower-type fan setup.
Nothing new there, except perhaps in it's application to Cryptocoin mining.

 Price is going to be critical to acceptance, though it IS nice to see them finally backing down from the "barely able to power it from a standard 15Amp USA home circuit" level stuff.

for $500 assuming you don't have any existing hardware, you can BARELY put together a single-board RX470, RX480, R9 290/390 system.

 Technically, you MIGHT manage a system with a single GTX 1060 but that's pretty close to a money-LOSER even now, unless you have FREE power, as the 1060 isn't a good Ethereum miner and doesn't seem to be very good at mining anything else.

 The 290/390 will get you about 30MH on Ethereum at a fairly high power usage, the RX470/480 closer to 24MH with quite a bit less power draw.

 NONE of those options are going to be particulaly profitable, as the power draw is going to be noticeably higher per hash due to the MB/CPU/RAM power draw.


 On the plus side - if you build it with the right motherboard, you CAN expand it fairly easily later by just adding more GPUs once you have more money to put into it.



 The other thing to keep in mind is that Ethereum profitability has been dropping pretty hard the last couple months, combination of more folks pointing more rigs at it and the INHERENT "DAG file size increase" reduction in hashrate on any given setup.
 
 Achieving ROI on Ethereum for any new build is looking like "if you have FREE power, you might manage it, otherwise probability pretty much ZERO" at this point in time, unless you put together a build you can resell a few months down the line for VERY close to what you paid for it - and somewhat iffy even THEN unless you have VERY VERY cheap power.

 Part of the reason I moved - "summer" power rate where I was at in Iowa was 15-16 cents/KWH range for 3 months of the year, depending on how much the power company was gouging for their "energy surcharge" that month.

 Nope, it's not FM2+.

 The -UD7 IS one of the very few motherboards around that will handle 4x dual width cards WITHOUT risers though, and was a very well reguarded board in it's time, and it WOULD be a good board for a no-riser 3 card build that leaves SPACE between dual-width boards (and is even usable for 3 cards no-risers with "2.5" width cards like some of the HIS "Ice-Q" blower model cards).

 I forget the exact spec on the CONNECTOR used for a PCI-E 6-pin connection, but I would ESTIMATE it is probably rated for at least 288 Watts.

 The ONLY difference between a PCI-E 6-pin and PCI-E 8-pin connection is that 2 GROUND leads get added - which doesn't add significantly to the actual power carrying capasity of the connection since it's going to be limited in both cases by the 3 x +12V lines, and if anything the 8-pin connector is going to thermally derate the individual connection pins a hair MORE than in a 6-pin connection.

150 watts through one of those connectors should be very conservatively safe, the PCI-E 75 watt rating for them is conservative beyond belief.

I'd be VERY cautious about that site.

 (1) They are NOT affiliated with the actual BitMain company

 (2) Looking at their prices, they are claiming to sell new Bitmain products in a few cases for LESS THAN THE MANUFACTURER DOES SO.


 I am picking up a distinct smell of "scam" about that site.



 Your electric price should make an S7 profitable for quite a while - if I wasn't hitting limits on available power, I'd probably have bought a few S7 units by now (my electric rate is almost identical, I suspect we're near neighbors).

Zoomhash is legitimate, but they never carried the S9 at all (and I don't think they bothered with the S7, though they DO carry the Avalon 6).

 I tried that for a while, but it was worthless *FOR ME* when I only check my email 1 or 2 times a day.

 It also has the SAME issue that it takes them a LONG TIME to figure out a miner has gone down at all - that's WHY I want the individual miner charts ON ONE PAGE so I can just glance at them occasionally and SEE that a miner crashed commonly within a few minutes of it doing so, instead of waiting 2-3 HOURS a lot of the time for their web page to finally decide "yup, that miner went down".


 It's less of an issue today than it was yesterday - profitability on my GTX 9xx based rigs dropped enough that I finally pulled them from Ethereum mining in favor of what I ORIGINALLY built them for - and they're actually making almost as much while doing stuff I class as "more useful".


 Next step - get the bloody Trinity A10 APUs replaced with updated ones that don't get disabled FOR NO BLOODY REASON when I put a discrete GPU in the machine that's not crossfireable. A10-7870Ks have gotten pretty affordable (the 7890K is still too pricey and doesn't offer significantly better performance, the 7860K "TDP LIMITS" out way too easily due to stupid BIOS on modern motherboard FORCING it to do so way too soon).


 Now if I could find a bloody FM2+ motherboard that has 3+ 16x slots (preferably with PROPER spacing, right now NO FM2+ motherboard spaces the damned slots right that I can find anywhere) AND doesn't force me to use USB for the damned mouse, I'd be happy!

 IMO the only reason to risk buying new gear (or even not-super-cheap USED gear) for mining Ethereum with is *IF* you were going to buy it anyway for some OTHER use, and plan to mine Ethereum just to help pay PART of the cost of the gear.


 Technically, planning to "resell" the gear might count, but I'd hate to COUNT on that with the rapidly declining profitability of Ethereum mining.

Driver limits make that "3 in one" extender pretty close to worthless, unless you're running a micro-ITX or mni-ATX board that only has 3 PCI-E slots or less.

 If you're running a full ATX motherboard, just get one that has enough slots natively - it will be more reliable as you're not needing to plug PCI-E risers into an extender for a DOUBLE whammy of potential connector issues.

 It's still profitable for me on my AMD rigs - though the profitability has dropped about a quarter over the last couple months.

 Profitability has dropped enough on my GTX 950 and GTX 960 based rigs that I dropped them from their "only intended to do it a short time to help pay for them" Ethereum mining to doing their originally intended purpose. I figure they probably paid for over half the cost of the video cards (I already HAD most of the rest of the hardware involved) over the course of the last couple months for the GTX 960s, and the GTX 950s are pretty much paid for as they were mining longer *AND* cost quite a bit less.

 Those rigs *ARE* still profitable - it's just that the GPUs involved aren't very good for Ethereum, while they CAN do some other "more usefull" stuff while pulling in a fairly close profit level.


 I'm debating seriously about building a few GTX 1070 based rigs - will probably mine with them for a while if I do, then shift to the same stuff I'm doing with the GTX 9xx rigs now, as the 1070 makes a TON more hashrate for not all that much more power. The questions there involve "they make more per watt, but they also COST a lot more per $ income" and I'm starting to push limits hard on both available cash AND available power.....



 GTX 1070 is a MUCH better card for Ethereum mining overall than the GTX 1080 - very similar hashrate, same or lower power efficiency, FAR LESS COST.
 GTX 1080 kicks on gaming and certain other usages, but for Ethereum it's a waste of money.

 SP20 was a LOT more comfortable at 110C on the chips, but the RockerBox had an ON CHIP temp sensor.
 Most of them DID run for a long time reliably at the "stock" 115c setting.

 Bitmain has never done that with ANY of their chips AFAIK, and "board level" sensors are a TON less reliable for detecting how hot the chips ON the board are actually running.
 That's a VERY GOOD REASON to not even think about pushing Bitmain miner temps.

 Litecoin, like all Scrypt-based coins, is dominated by ASIC miners. No point to even TRYING to mine it with a GPU much less a CPU.
 

Your miner is likely SO SLOW it's not generating enough hashrate to get any accepts on the BTC (SHA256) side.

 The old Gridseed GC3355 based miners FOR SHA256 were very very low hashrate, and have been a waste of power for Bitcoin/similar for quite a long time now.

 They're getting very marginal even on the Scrypt side - worthwhile if you have FREE power, but anything over about 4c/KWH and you're losing money with them even on Litecoin.

Are you using stock BIOS on that R9 290, or are you using one of the BIOS from TheStilt?

 Ghods, how do you make ANY profit with that crazy high of an electric rate?

 Even Ethereum has got to be getting marginal to LOSING MONEY at that electric rate.

 Saving 1-2% over a gold PS isn't a big deal if your electric price is DOUBLE what most bigger miners are paying.

 I suspect my electric would cost less if I used an 80% efficiency power supply than yours would for the same rig using a TITANIUM (93%+) efficiency power supply.

 DC actually travels BETTER over distance, due to AC suffering from skin effect.

 The REASON AC is more common is that it's a much lower technology need to change the VOLTAGE of AC power, and HIGHER VOLTAGE is a much more important consideration on losses for power transmission than skin effect is.



 Bills are generally in wattHOURS, not watts straight up - though some electric companies charge a "use fee" on some of their rates based on the peak watt usage IN ADDITION TO the actual charge for watthours.



 The problem with common lead-acid batteries is that while they might have a "nominal" voltage rating of 2Vdc per cell, they ACTUALLY have a normal voltage a fair bit more than that. A common auto "12V" battery usually has more like 13.5ish volts output at low amperage draw when full charged, and charging circuits commonly go as high as 15VDC.
 "12V" Gel Cells like many UPS units and some solar setups use tend to be in the same range as they use the same technology with some minor modifications to allow them to be sealed.