Starting a ZEC mining farm: Maximum ROI strategy.

[Faboo005]

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.

[philipma1957]

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.

good luck with your setup

but  for some  smOS is a good choice for running the gear.  rather then windows
I run as many as 13 rigs with 4 gps each headless using sOS
I have world wide internet access via an email link
and can set clocks along with monitor gear.
I can also change from coin to coin or pool to pool

Still like what you did with your setup a lot

[arielbit]

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.

i still got my 80gb (sata) HDDs i'm using since 2013, they are still fine..make sure you got good sata cables (i also have reserve stocks of these).

guess what...the windows 7 64bit i'm still using was installed in 2013, they are rock solid..

all i did was clone each HDDs..if a file system/bad sector problem occurs i do testing and repairs (results determine if it will be thrashed of re utilized), if it is okay(repaired) ... a clone will overwrite it and became a reserve HDD along with others.

cloning takes ~15-30 mins with all the settings/tweaks/drivers/miner software are all there.

looked at the pics...i don't like those HDDs, I think those are not good, have experience with those HDDs in the past, i'm using seagate slim type...the western digital (colored black) was good too.

my motherboards are $18, socket 775  4 slots..rock solid 

[PovertyByte]

Did you factor electricity before going at that income made per month?

Those previous gen AMD's guzzle twice the power that Pascal cards do for less hashes. Also the network difficulty will rise since you are likely not even close to the only one making a farm. The profitability you see now will not be your profitability in 2 months from now. Also ZEC is going to lose momentum when XZC implements MTP

Do consider the fact that the difficulty rises and earnings dip

[philipma1957]

Did you factor electricity before going at that income made per month?

Those previous gen AMD's guzzle twice the power that Pascal cards do for less hashes. Also the network difficulty will rise since you are likely not even close to the only one making a farm. The profitability you see now will not be your profitability in 2 months from now

He said his power is free

[PovertyByte]

Did you factor electricity before going at that income made per month?

Those previous gen AMD's guzzle twice the power that Pascal cards do for less hashes. Also the network difficulty will rise since you are likely not even close to the only one making a farm. The profitability you see now will not be your profitability in 2 months from now

He said his power is free

Wall of text. I skipped to the hardware selection

Quite an arrangement to get free electric and nobody batting an eye at how much is being used

[64dimensions]

A couple of things:

1) Full up system for spares/test/development. Say one MB, PSU, CPU. One cheap monitor. One Win10. One PCIe riser.

2) Taxes.

3) Rainy day budget.

4) If your business plan depends on free power, certainly a careful reading of the lease agreement is in order. Do you know the electrical supply limit of your space? Do you have access to the fuse box?

5) You may want to consider a few wall plug mounted transient suppressors if you are in an industrial space and your neighbors are using any equipment that draws intermittent amounts of electrical power, like arc welders or big motors.



 

[arielbit]

if ROI (profit is also made) is achieved and you are about to reach the maximum electrical limit (with allowance) try adding the top of the line GPUs who have a very high hashrate and very efficient..one by one in the process upgrading your gear.

mining area (space) and efficiency --> put this into the equation

my mining area is already getting filled and my electrical Amperage is about to reach my target, that's why I'm looking at 1080 ti (waiting for aftermarket coolers by different brands). also waiting for vega release..

[sigb0y]

@Faboo005
What do you use to connect two PSUs to one mainboard and what that it cost?

[Tigggger]

@Faboo005
What do you use to connect two PSUs to one mainboard and what that it cost?

I don't know what the OP uses, but I have always used the add2psu adaptors in my rigs.

You can chain them together, so you can mix and match different power supplies, so a small one can power 2 cards, some 3 etc.

http://www.add2psu.com/

You can see one on my titan at the front of the desk in the middle, the PSU on the right stays switched on and you turn the machine on/off with just the left



HTH

[PovertyByte]

if ROI (profit is also made) is achieved and you are about to reach the maximum electrical limit (with allowance) try adding the top of the line GPUs who have a very high hashrate and very efficient..one by one in the process upgrading your gear.

mining area (space) and efficiency --> put this into the equation

my mining area is already getting filled and my electrical Amperage is about to reach my target, that's why I'm looking at 1080 ti (waiting for aftermarket coolers by different brands). also waiting for vega release..

I was starting to think the same thing since the goal of the thread is maximum ROI. The question is what is OP's current budget to start off at on this setup. It may either be better to start off with the older GPU's and than to start of with less efficiency GPU's

[Faboo005]

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.
 

[chohav]

...

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 believe this is not the best advise to a newbie who is going to connect two PSUs working together for first time. Better use add2psu module. Anyway, if you use the method suggested by Faboo, be careful when powering on and off. Also you should turn on automatic turn on after power loss in bios setting.
BR

[adaseb]

Basically make sure both PSUs are grounded together somewhere and with the 2nd PSU (not connected to motherboard) attach a fan or something so if the other one shuts off it doesn't run without a load.

[sigb0y]

Thanks for the answers. I would try the add2psu device.

EDIT:
What about this cable? https://www.amazon.com/gp/product/B007OUNHL8/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

or this one?
https://www.amazon.com/gp/product/B00O0M6Q0C/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

[philipma1957]

Thanks for the answers. I would try the add2psu device.

EDIT:
What about this cable? https://www.amazon.com/gp/product/B007OUNHL8/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

or this one?
https://www.amazon.com/gp/product/B00O0M6Q0C/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

That will turn the psus on at the same time .

But you still need to either isolate the psus to prevent shorts.

If you have the correct psus they can be linked and not short out.

If you don't fully understand this shorts will happen

[sigb0y]

That will turn the psus on at the same time .

But you still need to either isolate the psus to prevent shorts.

If you have the correct psus they can be linked and not short out.

If you don't fully understand this shorts will happen

I do not understand. So it is better to use add2psu?

My PSUs are "Thermaltake Smart DPS Gold 750W":
http://de.thermaltake.com/Netzteile/Smart_Series_/Smart_DPS_G/C_00002723/Smart_DPS_G_750W_Gold/design.htm

Are they ok to be used with a cable?

[arielbit]

if ROI (profit is also made) is achieved and you are about to reach the maximum electrical limit (with allowance) try adding the top of the line GPUs who have a very high hashrate and very efficient..one by one in the process upgrading your gear.

mining area (space) and efficiency --> put this into the equation

my mining area is already getting filled and my electrical Amperage is about to reach my target, that's why I'm looking at 1080 ti (waiting for aftermarket coolers by different brands). also waiting for vega release..

I was starting to think the same thing since the goal of the thread is maximum ROI. The question is what is OP's current budget to start off at on this setup. It may either be better to start off with the older GPU's and than to start of with less efficiency GPU's

less efficient/older/cheaper...up to 3kw of free electricity, the target is cheapest gear to achieve maximum hashrate..after ROI, and going above 3kw, use the most efficient GPU/ PC components because the electricity is not free beyond 3kw, if it is profitable in the long run he can add more rigs and start to phase out the old and less efficient gear and upgrade to the most efficient one by one.

......

BTW i've never used an add2psu since 2013, i just always make sure that the second PSU only powers the extra GPU (it''s riser included)...

[ermolex]

nice article!
quite inspiring!

[Ambros]

You are very lucky (because of the energy) and your strategy is good!
Also consider that right now we are all getting almost double that the reward that we got for the last 6 months, ROI can be a little bit longer than expected if this bubble explodes

less efficient/older/cheaper...up to 3kw of free electricity, the target is cheapest gear to achieve maximum hashrate..after ROI, and going above 3kw, use the most efficient GPU/ PC components because the electricity is not free beyond 3kw, if it is profitable in the long run he can add more rigs and start to phase out the old and less efficient gear and upgrade to the most efficient one by one.

......

BTW i've never used an add2psu since 2013, i just always make sure that the second PSU only powers the extra GPU (it''s riser included)...

OT: You noticed any problem or instability un multi-PSU rigs? I would love to build a couple myself but with I do not wanna buy any extra component.