How big a rig is too big?

[joblo]

It's a boring Sunday afternoon so this topic popped into my head. There' been a lot of discussion about
rig building with some nice pictures, very interesting stuff.

But how big is too big? What is the limiting factor? Power limits of household circuits comes to mind
but that can be overcome with commercial power. Hard limits in software? With a well matched CPU and
lots of RAM just how many cards could a single rig support? Most big rigs seem to have 6 cards,
are there any bigger?

[sp_]

My fork supports up to 16 gpu's in a single rig. But most bioses have problems with more than 8. This might change with the nvlink interface.

[Tmdz]

Pci-e slots on the mainboard seem to be the primary factor.

[joblo]

Pci-e slots on the mainboard seem to be the primary factor.

I believe there are extenders to create more slots. PCIe bandwidth isn't an issue because you
can run a miner with one lane, so 1 16 lane slot could drive 16 GPUs mining theoretically.

OS and driver limitations could be an issue since neither Windows nor Nvidia are opensource.
Linux and open source AMD drivers (do they work?) might be a possibility since anyone with
the skills could mod the code to raise the limit.

[Ayers]

i think it's not wise to go with many gpu on a single rig, you need anyway to pay for additional psu, nothing will change for the wattage, and you need to buy splitter that cost a lot, like the other part of another rig, which are cheap anyway

[Searing]

It's a boring Sunday afternoon so this topic popped into my head. There' been a lot of discussion about
rig building with some nice pictures, very interesting stuff.

But how big is too big? What is the limiting factor? Power limits of household circuits comes to mind
but that can be overcome with commercial power. Hard limits in software? With a well matched CPU and
lots of RAM just how many cards could a single rig support? Most big rigs seem to have 6 cards,
are there any bigger?

Well my 4th (kinda) Titan is going up under my 100 amp service (no issues but I have boiler heat and no central A/C) no issues

14 cubes 3 controllers 4 power supplies (3 corsair 1200i's and 1 seasonic 860w all platinum)

So if you flip your question to how big is too big...probably already too big (so addicted i am to home mining)

it is 'nerd city' in my basement however

lostgonzo.imgur.com (10 cubes shown no pics of last 4 cube rig yet)

Also note the 8 slot sub panel off my 32 sized slot 100 amp panel ...check out YouTube videos on such ..easy to do  if you need more slots.

(addicted I am to home mining ..the horror)

[joblo]

i think it's not wise to go with many gpu on a single rig, you need anyway to pay for additional psu, nothing will change for the wattage, and you need to buy splitter that cost a lot, like the other part of another rig, which are cheap anyway

I tend to agree. Once you start needing multiple PSUs and port multipliers it's probably better to build a
seperate rig.

[philipma1957]

i think it's not wise to go with many gpu on a single rig, you need anyway to pay for additional psu, nothing will change for the wattage, and you need to buy splitter that cost a lot, like the other part of another rig, which are cheap anyway

stick at 5 or 6 cards per rig.  


make a second rig at that point.


reasons are simple enough.

1)  if one rig fails  you are still mining on the other rig.

2)  cooling may be easier with two rigs   ie use a  separate room

3)  you can do one rig at each pool

4) cost for the asrock board is under 100

5) cost for windows 7 is under 50

6) cost for some ram is under 40

7) cheap ssd is under 60    

8 ) so the net extra is  under 250     you get a lot for the 250

9) if a second coin arises  besides Eth  one rig on eth on rig on new coin

[joblo]

i think it's not wise to go with many gpu on a single rig, you need anyway to pay for additional psu, nothing will change for the wattage, and you need to buy splitter that cost a lot, like the other part of another rig, which are cheap anyway

stick at 5 or 6 cards per rig.  


make a second rig at that point.


reasons are simple enough.

1)  if one rig fails  you are still mining on the other rig.

2)  cooling may be easier with two rigs   ie use a  separate room

3)  you can do one rig at each pool

4) cost for the asrock board is under 100

5) cost for windows 7 is under 50

6) cost for some ram is under 40

7) cheap ssd is under 60    

8 ) so the net extra is  under 250     you get a lot for the 250

9) if a second coin arises  besides Eth  one rig on eth on rig on new coin

Well put. A few comments:

2) limited cable length would increase the card density and heat concentration.

3) hadn't thought of that, a little easier than running 2 instances on one rig.

5) linux is free and has better remote management.

10) No risk rig will overload electric circuit.

[Amph]

well windows 7 is actually free, you know what i mean, you can argue that we can be infected because of torrent and stuff like that

but i have my own 100% secure copy(plenty of btc transaction using this copy, no infection in years) that i'll use for all my rig

[QuintLeo]

Windows 10 is OFFICIALLY free (in at least one version) for a short while longer - if you don't mind issues with buggy driver versions etc.

 Seems like the only time Microsoft does a SERIOUS beta test of any of their OSs is right after they release a serious turkey (anyone remember MS-DOS 5 being the FIRST Microsoft OS with a wide beta release - after MS-DOS 4.0's issues with Smartdrive)?

[QuintLeo]

IMO the hassles of coordinating multiple power supplies isn't worth doing - so however many cards you can run from one PS would be where I set the limit.

[Amph]

Windows 10 is OFFICIALLY free (in at least one version) for a short while longer - if you don't mind issues with buggy driver versions etc.

 Seems like the only time Microsoft does a SERIOUS beta test of any of their OSs is right after they release a serious turkey (anyone remember MS-DOS 5 being the FIRST Microsoft OS with a wide beta release - after MS-DOS 4.0's issues with Smartdrive)?

windows 10 is not that good if you have nvidia and want to mine etheruem, even with the drivers fix, you still will not reach the same hash like in windows 7

[sp_]

If you have more than 6 cards,you need powered risers . A 750ti draws 50-60 watt depending on what you mine. So a 16 cards rig will only draw around 1000W. The bios might need to be cracked to support 16 cards, and more than 8 cards in windows is a pain.  Have anyone tried 5 7990's in one single rig ? (10 gpu's)
You probobly need linux. Expensive PCIE splitters etc.

[atp1916]

You'll be limited in the end by the OS card limits AND the make of card you're using (AMD or NVidia).

With Windows, it's usually 6-8 AMD cards (see lbr's AMD driver mods - tip him, plx) 

I have seen higher limits with *nix OS kernels, but that's with some serious hackery.

NVidia cards i am not sure about given my lack of experience with them and mining.

[Ayers]

If you have more than 6 cards,you need powered risers . A 750ti draws 50-60 watt depending on what you mine. So a 16 cards rig will only draw around 1000W. The bios might need to be cracked to support 16 cards, and more than 8 cards in windows is a pain.  Have anyone tried 5 7990's in one single rig ? (10 gpu's)
You probobly need linux. Expensive PCIE splitters etc.

powered riser are useless if you have asrock h81 with two molex, i always used ribbon standard risers and they work fine for every card out there, also cost less than powered riser

[Gotomoon]

If you have more than 6 cards,you need powered risers . A 750ti draws 50-60 watt depending on what you mine. So a 16 cards rig will only draw around 1000W. The bios might need to be cracked to support 16 cards, and more than 8 cards in windows is a pain.  Have anyone tried 5 7990's in one single rig ? (10 gpu's)
You probobly need linux. Expensive PCIE splitters etc.

powered riser are useless if you have asrock h81 with two molex, i always used ribbon standard risers and they work fine for every card out there, also cost less than powered riser

That is right. When I use the H61 or H81 pro btc motherboard, I do not use powered risers. It is just a waste.

[MinerDudeRigs]

I like 6 cards per rig, it's my happy medium.

[joblo]

If you have more than 6 cards,you need powered risers . A 750ti draws 50-60 watt depending on what you mine. So a 16 cards rig will only draw around 1000W. The bios might need to be cracked to support 16 cards, and more than 8 cards in windows is a pain.  Have anyone tried 5 7990's in one single rig ? (10 gpu's)
You probobly need linux. Expensive PCIE splitters etc.

powered riser are useless if you have asrock h81 with two molex, i always used ribbon standard risers and they work fine for every card out there, also cost less than powered riser

I have to disagree. Although the mobo can supply the power cheap risers sometimes can't. At least with powered risers
you're not trying to push 75W through a ribbon wire. It also reduces the overall power going through the mobo. The cost
difference is trivial, no more than .05 BTC with risers on all 6 cards.

If using two PSUs (not my thing) I believe you need powered risers to isolate them.

[Ayers]

If you have more than 6 cards,you need powered risers . A 750ti draws 50-60 watt depending on what you mine. So a 16 cards rig will only draw around 1000W. The bios might need to be cracked to support 16 cards, and more than 8 cards in windows is a pain.  Have anyone tried 5 7990's in one single rig ? (10 gpu's)
You probobly need linux. Expensive PCIE splitters etc.

powered riser are useless if you have asrock h81 with two molex, i always used ribbon standard risers and they work fine for every card out there, also cost less than powered riser

I have to disagree. Although the mobo can supply the power cheap risers sometimes can't. At least with powered risers
you're not trying to push 75W through a ribbon wire. It also reduces the overall power going through the mobo. The cost
difference is trivial, no more than .05 BTC with risers on all 6 cards.

If using two PSUs (not my thing) I believe you need powered risers to isolate them.

average wattage per card today, especially with new nvidia is very low, they consume 150w on average, very low as i said they will use the 8 pin if not enough current come from the x1 slot, i think you don't need to provide 75w fromt he slot, lol future gpu with 10nm or less, will consume so low that not even a 6 or 8 pin would be required, only the riser