I wish they would advertise that, didn't know about that discount.

 8-(

I'm pulling somewhat over $1000 (but paying out about $300 of that to the electric company) on my current set of miners per month.
Ballpark $450-$500 range from the A2 farm depending on Litecoin price/diff each day (which is pretty much paid off at this point, but those things eat ballpark 2/3ds of the electric) and the rest from an assortment of stuff mining ETH.
Just switched the NVidia rigs over to something else though that's just become more profitable (and happens to be my LONG-TERM intent for building those rigs in the first place), and have MOST of the parts on hand to add a couple more of those.

 I paid $49 or something like that for a 5-shelf "Muscle Rack" wood-shelf unit from Home Depot a couple months back.
 It's rated to handle MORE load than any wire rack I've seen short of high-end commercial EXPEN$$IVE stuff.

 It's "only" 36" wide not 48" but less $$ on a per-unit basis - should be able to handle 2 6-card rigs per shelf with enough space between the cards for decent cooling.


 I've seen the 4-shelf varients on sale regularly for around $30.

double-check your xorg.conf - Ubuntu 14.04 has a nasty bug where it will delete or overwrite that file when it reboots.

 Workaround THAT WORKS is to disable gpumanager in your grub setup.

 Mainstream cards - IF you can make enough of them - sell so many more that they make a TON more money - and AMD has been having cash-flow issues and profit issues for a while.
 They specifically targeted "where the money is".

 NVidia obviously felt they could afford to "coast" with their existing 9xx series cards for a while in the "mainstream" area.

 You have them too close together, or you aren't getting adequate air feed TO the cards from outside the case - perhaps both.

Actually, the reason is that for most cryptocoin algorythms the AMD stream processors are EQUALLY effective as the NVidia CUDA cores - but AMD cards of the "same class" have MORE stream processors.

 I don't think I've seen ANY CUDA card (possible exception for one of the Titans) that had 3000 CUDA cores - but AMD has put up to 4096 on cards (FuryX and Nano specifically) - NOT counting "dual GPU chip" cards like the Duo or the R9 295X.

 Clock rate is also a factor where the core count matters, but that's usually been quite close between the two manufacturers at any given time.

 Why not just buy one of the wood-shelf type racks instead of having to use a seperate piece of wood (that adds cost)?

 Home Depot, Menards, and Lowes all sell low-cost ones, usually for the same OR LESS than those wire-rack things.

It doesn't look like you set up your xorg.conf file?

 aticonfig --initial --force should fix that part.

 without xorg.conf set up right, the fglrx driver never gets loaded.

 Unless you have free electricity, you will never make enough from ANY stick-type miner to pay for it's cost.

 On the plus side, the Gekko gets the CLOSEST to doing so.

 Your best bet with it is probably to treat it as a "lottery" device and solo mine with it.
 Alternatively, use it to learn how to set up stuff for a miner with the plan to eventually get at least one Bitcoin miner with a SIGNIFICANT hashrate at some point in the future.

 Much less of an issue with the 14/16nm generation, as ASIC mining gear has caught up with semiconductor state-of-the-art now - we won't see 6 month to year "generation" cycles any more as in the past when the tech in the miners was still BEHIND the state of the art for semiconductors as a whole.

 I expect to see more like a 3-4 year "cycle" in the future, as that's been what general semiconductor tech has been averaging for a while - and we're looking at a significant change of a longer "blip" right now as EVERYONE that does semiconductor manufacturing research has stated that 10nm is "END OF THE LINE" for silicon.

 I have a feeling we're getting down far enough into "quantum effects are a major issue" territory on semiconductors that we might only see 1 or 2 more generations before 2030, unless there is a HUGE paradigm shift in the industry.


 I won't be shocked if the S9 remains a profitable unit into the mid-2020s at 4c/KWH electric.

 The Thermaltake can take 3 x 38MM fans in the front with minimal to no modification though. 3x Delta 200+ CFM fans WILL keep your cards cool, though realistically you only need 1 or 2 down in the area the cards are in - the 3'd one installs in place of the external drive mounts and doesn't blow much air down to the GPU area if any. Or move the drive cage to the middle, mount both of the included 25mm 120s at top and middle, and a Delta 38mm in the bottom.
The main issue with it is that the clearance between the last card and the PS is low - not an issue if you're using blower-type cards and a fairly short PS as the blower fan will stick out past the PS.
 (edit) still no clue what the difference between the V34 and the V35 is, but they have a V31 with front-mount buttons/USB instead of the top-mount stuff on the V34, that's probably going to be the case I go with in the future for any case-type builds I do, or if/when I decide to sell off some of my existing builds to gamers.

 I don't like side fans as a general rule 'cause they just don't tend to work as efficiently as straight-through flow does - and if you intend to rack mount a system, side fans are NOT AN OPTION.


 I've tried a couple other "8 peripheral slot" cases and been VERY UNHAPPY with them due to very poor cooling design restriction to 25mm OR THINNER fans in too many spots, though I haven't tried any Rosewill models yet.


 Back plates are a major PAIN for multi-card builds, they restrict the airflow too much.
 I avoid the things.

 I suppose I should try my pair on XMR sometime - they're only pulling about 10MH/s on ETH though that's at 75ish watts, which isn't bad for last-gen cards.



 Down side of the FX 8xxx and comparable Opterons that get higher hashrates is the power draw is also fairly high - comparable to most mid-range GPUs.
 Seems like Intel beats AMD hands-down on XMR mining, better AES-NI support or something.

GTX 960 (no M, not sure if that's the "MOBILE" version or something else?) is good for around 11Mh/s on Ethereum at fairly low wattage without pushing the memory clocks to unstable levels.


Forget trying to mine Bitcoin (or ANY OTHER SHA256-based coin, any Scrypt-based coin like Litecoin and Doge, or any X11-based coin like DASH) on a GPU, as ASIC have taken all of those over and are a TON more efficient, having bumped difficulty on ALL of those so high you can't break even on a GPU even with super cheap electric. On Scrypt and probably on X11, you won't make enough to pay for the card before it dies on FREE electric. On SHA256, you won't even get CLOSE - if you can mine $1/YEAR worth of Bitcoin on any GPU available today I'd be supprised.

 For perspective - best GPUs mining on Bitcoin before the first FPGA and ASIC units were introduced mined at ballpark 1 GH/s - might manage 2-3 GH/s on the best cards available today - and you'd be eating well over 100 watts to achieve that.
 The S9 (current best-efficiency ASCI miner) manages appx 14 THOUSAND GH/s - on about 1300 watts power usage. Over 1000 times as efficient.
 Even the 2 generation old S5 units (that are no longer MADE 'cause they aren't efficient enough) managed over 1100 GH/s on appx. 550 watts power usage, still over 200 times the efficiency.


 "A few decades ago" even on Bitcoin though isn't right - for X11 more like early THIS year, for Scrypt about 3 years back, 5-6 for SHA256.


 FREE electric isn't a requirement to mine profitably, though very very LOW cost electric is a major factor in being able to achieve ROI on any piece of mining gear.


 Additionally, NVidia cards aren't particularly good on most cryptocoin mining algorythms.
 They're closer on the memory-intensive ones like ETH/ETC but tend to cost more for the same hashrate vs AMD cards even there, and on many algorythms AMD cards blow away NVidia on hashrate entirely.
 There are a few algorythms the NVidia cards are competative on in a Hash/Watt basis, but on hash/$ they're not competative even on THOSE algorythms.


 I won't say GPU mining is AMD-specific - but it's strongly AMDcentric.

 Someone that is mining with Titans has either bought them used recently, or has LONG SINCE paid off the cost to buy them.

 Also, why ASSUME spread cost over 12 months - the Titan has been around a lot longer than that, the S9 hasn't been around THAT long yet.

 "September release" in THIS industry, even from reputable makers, usually means "we're AIMING for end of September, but might slip into October or even November".

RX 480 has a few more cores than the RX 470, but seems to use the same or nearly the same memory subsystem.
It's possible the RX 470 uses cores designed for the RX480 but disable one section internally due to testing showing that one section bad.

 8GB vs 4GB should not affect hash rates, unless one size uses different memory modules with faster timings.

 CPU mining for ETH or ETC = don't bother, not even close to efficient compared to GPU.

 CPU mining for XMR seems do depend a TON on your specific CPU, and if it supports the AI-NIS (might be mispelling that) cryptography-specific instruction set extensions.
 I'm not sure where Intel started that support exactly, 2-3 generations back though - AMD started that support with the Bulldozer-based cores AFAIK (any APU and the same timeframe FX series)

 That Rosewill case SHOULD work for a 4 card build on the Biostar motherboard Phil said he's using.
 Case I found that would also work though clearance between the PS and the last card is marginal is a Thermaltake:
 http://www.newegg.com/Product/Product.aspx?Item=N82E16811133270
 Their V35 model appears to be the same case, I've never figured out what the difference between those 2 is.

 But I'm going with "open" builds as of my last build (parts for 2 more in shipping right now).

 Mining CAN be profitable - but it's largely a function of your electric cost as to the probability of it being profitable ENOUGH to make back what you pay for the hardware, and there also tends to be a "timing" aspect on every generation of gear.


 To those that claim solar power is cheap - try factoring the COST OF THE EQUIPMENT over it's expected lifetime. Without major subsidies, Solar is one of the MOST expensive ways to generate power on a 24/7 basis unless you live VERY FAR out in the boonies where running a power line would cost a ton.

Realistically, you'll need AT LEAST 2 motherboards - you'll pay a LOT less splitting it into 2 rigs than trying to put all of those cards on one rig.
You're going to NEED 2 power supplies as well to handle THAT many 280x.

 The FuryX and Nano had 4096 shader/Stream units - on 28nm process on a single chip (the Duo had 8196 but that was 2 chips on one card).
 No reason 14/16nm can't end up with half again to double that on a true high-end card.