For sale is the 280X part of my farm. They use too much power to suit my garage any longer.

These ideally suit somebody with low electric cost. They average 300H/S ZEC, so are still perfectly profitable even with standard electric costs. They run about 200w/card- slightly higher for the 7970s.

They have been used as miners for around 4 months. They are stable, have good fans, and have always been run in a very well ventilated garage keeping them cool and happy. They are all 100% tested and working, and are mostly mining as I type, bar the 4 I had to switch off to stop the fuse blowing.  

The items for sale are:

10x R9 280X Cards - £120 each, mixed brands, assume no boxes.  **Now Reduced to £105**
2x 7970 Cards,- £100 AMD reference coolers.  ***Now Reduced to £90***

Items are in the UK, near Gatwick. If you are local you are very welcome to come see them working and pay cash. If you are not local you are welcome to see a video of them working and pay BTC escrow. Shipping will be tracked and signed for. Shipping to the UK is free if you take the lot, or £6/box if you don't take them all. Shipping to the EU will be an extra £20/box.

Priority will go to a buyer taking all of them. Serial numbers will be recorded, along with video evidence of the cards working before shipping.

I can include the DVI Dummy plugs if required. The other hardware is not included, but feel free to inquire about it if you really want it.

Shit wrong sub. Mods please move, i cant delete.

For sale is the 280X part of my farm. They use too much power to suit my garage any longer (when my wife puts the drier on the fuse blows and I get shouted at), so need to find a new home.

These ideally suit somebody with low electric cost. They average 300H/S ZEC, so are still perfectly profitable even with standard electric costs. They run about 200w/card- slightly higher for the 7970s.

They have been used as miners for around 4 months. They are stable, have good fans, and have always been run in a very well ventilated garage keeping them cool and happy. They are all 100% tested and working, and are mostly mining as I type, bar the 4 I had to switch off to stop the fuse blowing.  

The items for sale are:

10x R9 280X Cards - £120 each, mixed brands, assume no boxes.
2x 7970 Cards,- £100 AMD reference coolers.

Items are in the UK, near Gatwick. If you are local you are very welcome to come see them working and pay cash. If you are not local you are welcome to see a video of them working and pay BTC escrow. Shipping will be tracked and signed for. Shipping to the UK is free if you take the lot, or £6/box if you don't take them all. Shipping to the EU will be an extra £20/box.

Priority will go to a buyer taking all of them. Serial numbers will be recorded, along with video evidence of the cards working before shipping.

I can include the DVI Dummy plugs if required. The other hardware is not included, but feel free to inquire about it if you really want it.

Most miners dont support ATI cards older than the R9 series. So if youre on a 6870 or something it probably wont work, and even if it did it wouldnt be profitable.

Yeah make sure you plugged in the power for the 8 pin. Also try a CMOS reset on the jumper if you have not already.

Another thing to look for is any short circuits, if you have it installed on a metal frame or some kind of getto shelf or whatever.

I mine with 295x2 cards.

I mine on ETH, they produce about 55MH each.

The main problem with them is finding a tidy place to put the fan, and keeping them cool. Also avoid automated driver updates at all cost, as some of the more modern drivers will break your cards. This is also a good reason not to mix in modern RX cards.

I wrote more about this here: http://blockchurn.com/2017/07/04/is-the-r9-295x2-the-miners-holy-grail/

I need more of these cards. what's the asking price?

Are these still for sale? Do you have the original coolers? Would take all 3 GPUs at £115 each or BTC equivalent, but i don't want to run them in a water loop.

If youll take 450 i'll take it off your hands. I'm afraid I don't think it's worth more than that.

Not really. Even with electricity at 10p/KW I loose only about 1/3rd the income. It's still highly viable.

Yeah I find the second PSU thing works totally fine without any supporting hardware or anything like that. Just short the green and black wires to switch it on, and use it to power additional cards. I don't really understand why people are saying that doesnt work or is bad. I've been running systems like that for months with no damage to PSUs or hardware.

We rent an industrial unit for another business I run. As part of that we get free electricity. I can push what I've got right now (about 3kw) as part of the lease. The landlord agreed I could use up to 10kw, but I'd have to pay £0.10/KWh for everything I use beyond the 3KW, and pay for some rewiring to get it to our unit from the main inlet. Right now with the high value of ZEC/BTC 10p/kw is viable, but i don't know how long that will last so i'm cautious of scaling.

I think cheap 80GB hard drives would probably work, if they were at least in good condition. The ones we got used off ebay must have seen a lifetime of heavy use. I guess there is a luck factor here too.

Using two PSUs to power one rig is easy. Plug one into the motherboard normally and use its PCI cables to connect up a couple of graphics cards. Then on the second one just force it on by shorting out the green wire to a black wire on the main motherboard header- then use it's PCIE connectors and Molex's to power cards.
 

I started a small farm! I have been building it this week. This is what i've learnt.

I now make £1260 per month. I spent around £3225.

I get free electricity included in my industrial rent so that wasn't a concern. My goal was the quickest possible ROI. I got it down to about 10 weeks to recoup 100% of my costs with this method.

Album here: http://imgur.com/a/xj449 (note this was before completion, just the first rack was done. Some detailed changes were not yet made).

Software
This is what you want to install on your hard drive when you set up:

I've been running clean installs of Windows 10. I tried linux, but unless you know what you're doing everything just takes 10x longer while you figure it out. Stick to Windows 10 if you're new. You can get windows from M$'s website, create a bootable USB, and install. When it asks for a product key, just tell it you don't have one and then install Pro. If it ever demands it you can buy them on ebay for ~£15.

Once installed, install the various chipset drivers, along with the AMD drivers. Using the right drivers DOES make a difference, so use the recommended 15.12 (make sure you uncheck the auto-update it asks for at the end of the install). If you're using RX4* series cards, you'll have to use newer drivers.

Claymore's miner (versions 12 and on) and Optimer (versions 1.6 and on) are both great. I think Claymore produces higher hashes overall. Use one or the other.

Claymore talks about putting in Environment Variables and setting the virtual memory, but doesn't explain where to do this. Right click the start icon, choose system, then advanced system settings. The virtual memory is under Performance settings, and the Environment Variables are at the bottom of that box. Once youve opened Environment Variables, click New under System Variables,  set the Variable Name as per Claymore's Readme, and the value as the number he gives. Then Ok when done. If i'm honest i've not noticed this making a huge difference on my systems. Also in windows add the miner to the startup list so you don't have to do it after a reboot, and change the power options to HIGH PERFORMANCE so it doesn't set the computer to sleep after half an hour of mining!

For remote access, use Teamviewer. It's simple and it works. That way you don't have to have a monitor etc. plugged into every rig.

Hardware
GPUs I went the route of buying cheap GPUs on Ebay or other used stores. I got about 15 R9 280X cards for an average of £70, and a handful of 290x for around £100. If they don't work, you can return them so who cares. Cards the seller claims are artifacting almost always hash fine. Cards with bad fans are easy to fix (take the bad fan out, strap an 80mm fan on instead with some cable ties). Buying cards with irrelevant defects will save you a fortune. You can also find some great deals by just watching ebay for auctions ending at bad times (I got a 7990 for £140, and a Pro Duo for £370. That's 1.6KH right there, in just two slots.) I think these cards will loose no more than £20 value/year, so you can always resell them when it's time to upgrade. Note that 280X cards are power hungry. I can't expand the farm because i'm using all the power I can get without pushing the wiring too far. That is the only major flaw- to go bigger i'd need to use lower power cards.

PSUS
When people say on here that cheap PSUs are a waste of time, they're right. I tried those 1000w on ebay for £30 PSUs. They both broke after running a single 280x for about 2 weeks. Utter garbage. Then again I think the £180+ 1000w brand name PSUs are also a waste of time and a hard to resell. Brand name PSUs hold their value very well so are a fairly safe investment. I like PSUs around the 750w/£60 mark from the half decent brands (Cooler Master, Antec, EVGA). Yes you need 2/rig, but I'd rather have 2 PSUS per rig for a total cost of £120 than one running £180 or more. It also means you can keep hashing at half speed if one breaks, and they are easy to sell on Ebay later for just a little below retail, so also very little risk of value loss.

Motherboards & CPUs
Motherboards and CPUs loose value faster than GPUs and PSUs, so I think you want to be careful here. You also want as many PCIE slots as possible. But the big 6+ slotter motherboards are now all £120 plus, often £150 or more. Give it a few years and they will be worth 1/3 of that. I went with the ASUS H81M-PLUS giving 4 slots for around £50. Stick a celeron in there for about £25, and a stick of cheap DDR3 (at least 2GB) and you're good. The cost/slot here is fine, that's all you're really interested in.

Harddrives
I made the mistake of going for cheap ebay 80GB HDDs for £5 each.  That was the biggest mistake i made in this whole project. I invested hours into install windows and drivers onto hard drives that then died outright, or were PAINFULLY slow at the desktop. Either buy £25 60GB SSDs, or NEW 80GB mechanical. Don't go cheap here,  it will drive you nuts later.

Risers
Get the good risers on ebay, they should be about £5 each. There is a cheaper version than that, the ones without the little PCB board at the base of the slot- but I found those had a very high failure rate- and were a short circuit risk.

Molex Adaptors ETC
I found a website called http://www.kenable.co.uk/ which if you're in the UK does some really handy stuff like Molex>8pin adaptors for very little money. Quality seems okay.

Casing
Those metal cases people are selling for £100+ are a stupid idea if you want to make your money back fast. I used old wooden ikea shelves we had laying around. Use whatever you can find. Plastic tubs look shit, but they work. Plastic or wooden shelves are where it's at!

Cooling
I went to Wicks and bought 10 lengths of wood for £11. I built them into a large frame (95x85x160cm) which sits around the miners. It is wrapped around the sides and top with bubble wrap to insulate and keep the heat in. There is a 3m plastic tube duct (£7 from amazon) which goes into the top of the frame through the bubble wrap, which extracts the warm air (I happened to have an in-line cooling fan, but those can be expensive) and pumps it out an open window. Cooling sorted. Otherwise the room does cook.

That's it! I hope that helps somebody.

Cost break down:
15x 280X £1050 4200H/S
3x 290X £360 960H/S
2x Dual GPUs £510 1600H/S
5x mobo/cpu/ram/hdd £575
10x PSU £600
20 x Riser £100
1x Misc £30
Total: £3225

Return: £1260/month.

I get more like 300 on stock settings with stock bios, 8GB card, Claymore 12.4, i8. Probably could be pushed to 330 with a bit of work.

Does anybody know how much system RAM volume matters to intensities?

I have various cards spread over a few rigs. I've noticed some reduce intensity on the basis of not enough memory, where other rigs with the same GPUs dont. I assumed this was linked to GPU memory, but the cards are the same with the same 3gb. So is this reduction actually linked to system RAM volume?

This card is still available. Price is negotiable, as noted above RRP has dropped a bit.

Picture of card:

Im at home now. Ill get you a picture from the office tomorrow.

I have an excess used Sapphire RX480 8GB that I lack a spare PCI slot for. All tested and working fine.

I'm asking the spot BTC, ZEC, or GBP equivalent of £240 (or best offer) UK next-day delivered for it, or £245 with a riser.  Will ship to Europe too- mainland Western Europe shipping is £8. Further afield may bit a little more.

Escrow is fine if you cover any fees.
 

Okay. Ill PM.

Would you ship to UK?