Does CPU affect how many GPUs you can run?

[MrBilling]

I have been trying to get 5 to run with this CPU.


http://www.newegg.com/Product/Product.aspx?Item=N82E16819103953

Its an Athlon II 270.

[os2sam]

I have been trying to get 5 to run with this CPU.


http://www.newegg.com/Product/Product.aspx?Item=N82E16819103953

Its an Athlon II 270.

That's a much higher end CPU than most miners.  My Athlon II 250 runs around 5%.

So what problem are you having?
Sam

[MrBilling]

Not being able to run 5 GPUs.


I am using a mob on the BAMT compatibility list as working with 5 GPUs.


Plus I have read other people on here running 5 GPUs with it.


Its the ASRock 970 Extreme4.



I was just wondering if maybe the CPU had something to do with it.

[os2sam]

Not being able to run 5 GPUs.


I am using a mob on the BAMT compatibility list as working with 5 GPUs.


Plus I have read other people on here running 5 GPUs with it.


Its the ASRock 970 Extreme4.



I was just wondering if maybe the CPU had something to do with it.

I seriously doubt it.  I'm using Windoze 7 32 bit, so I don't know anything about mob's or bamt's.  Provide some details and maybe others would be able to help.
Good Luck,
Sam

[SkyNet]

people have been reporting issues with more than 4 GPUs in Windows. Linux works fine.
Which OS are you running?

[MrBilling]

I am using BAMT.  Thats why I was saying the mobo is on the BAMT hardware compatability list as working with 5 GPUs.


I have tried every combo.  Risers, both powered and non powered.  I have tried using all X1 risers.  It just wont boot with more than 4 GPUs.

[philips]

When you say it doesn't boot you mean it just stands there at the boot screen?
Or it starts and stops half way?

Try to start BAMT in safe mode (choose at the boot screen) and if it starts look in the upper right corner, how many cards are listed?

Or, enter in terminal:

Code:

aticonfig --list-adapters

[MrBilling]

I just got done doing some more testing.



This board has 3 X16 and 2 X1.


If I plug 3 cards straight into the board (no risers) and one card into one of the X1 slots it will work perfectly.  so this is 4 cards.  If I try three cards directly into the board and 2 cards on the X1 on risers it wont boot.  It will boot and show the BAMT loading screen but then it goes blank.



Another member told me that this board only has 22 lanes, they said 24 but after confirming the AMD 970 chipset only supports 22 lanes.




So I tried plugging 5 cards in all with 5 X1 risers.  It would boot into BAMT but no matter what I do it will not show the card in the second X16 slot.  I tried switching cards, switching risers cables, shorting the presence pins, nothing.


I see alot of people reccomend boards with the AMD 890FX chipset.   Like the 890FXA-GD70 MSI board.   The 890 chipset supports 38 lanes just like the newer 990 chipset does.


I might try ordering a 990 chipset board.  Like the ASRock 990FX Extreme4, or MSI 990FXA-GD80.

[philips]

 If I try three cards directly into the board and 2 cards on the X1 on risers  it wont boot. It will boot and show the BAMT loading screen but then it goes blank.

In this configuration try to boot BAMT in safe mode.

I have the same issue with 5 cards, in normal mode BAMT goes blank, while in safe mode it works just fine.
Never bothered to find out why, I just start it in safe mode.

[MrBilling]

 If I try three cards directly into the board and 2 cards on the X1 on risers  it wont boot. It will boot and show the BAMT loading screen but then it goes blank.

In this configuration try to boot BAMT in safe mode.

I have the same issue with 5 cards, in normal mode BAMT goes blank, while in safe mode it works just fine.
Never bothered to find out why, I just start it in safe mode.

OK So you are talking about failsafe right?  Where it says boot the BAMT then below that it says boot the BAMT (failsafe).



So I moved the cards back to three directly on the board no risers and one on a X1 adapter.  So 4 cards.  Just to make sure it still works that way.  It worked.

So I installed the 5th card into the other X1 slot with a X1 adapter.  Tried to boot.  No luck.  So I tried to boot into safe mode (failsafe) and it still wouldn't work.


So as a last resort I shorted the presence pins on the 5th card.  Tried to boot it.  No luck.  Tried to boot it into safe mode (failsafe) and IT WORKED!



So for the second time you saved my a** Phillips.  Thank you so so so much.




I hope it always works like this booting into safe mode.   So you have to boot into safe mode every time you boot your rig?

[-ck]

When I first put my 4 7970s into my rig, Xorg would refuse to start with the gdm gnome login manager. If I started a bare bones Xorg as a regular user, it would start. So I left it mining like that.

[MrBilling]

Ive got some tweaking to do.



Before with 4 cards I could get 600 KH/s.  Now with those same settings BAMT freezes up after about an hour.  I tried lowereing the clocks from 1100/1375 to 1050/1250 and it froze again.


Ive got it on 1000/1200 now.  See if it helps.  I also lowered the thread concurrency from 19000 to 16000.



Should running 5 cards be the same as running 4?  Or is running 5 cards generally more unstable?

[ewitte]

My celeron handles both BTC and LTC just as good as the 6 core Xeon.

[Operatr]

You can go very minimal for a mining processor. There is a  $40 Sempron in mine.

GPUs are actually doing all the work, so the processor doesn't have to be much in the way of power, just enough to to run an operating system with. Processors don't much use in mining as their multi-purpose architecture makes them very inefficient at hashing. GPUs architecture is much more hash friendly. You don't need much RAM either, anything beyond 2Gb won't make your rig mine any faster, you could probably use less though for general system speed I would say 4gb max, as memory is pretty cheap anyway.

All that really limits how many GPUs you can run is how many PCIe slots you have available, and your power supply.

[philips]

Ive got some tweaking to do.



Before with 4 cards I could get 600 KH/s.  Now with those same settings BAMT freezes up after about an hour.  I tried lowereing the clocks from 1100/1375 to 1050/1250 and it froze again.


Ive got it on 1000/1200 now.  See if it helps.  I also lowered the thread concurrency from 19000 to 16000.



Should running 5 cards be the same as running 4?  Or is running 5 cards generally more unstable?

What PSU do you have?

[MrBilling]

Right now I have 4 cards running off of a 1200W Silverstone Gold, and the other card running off of a 1200W Cooler Master Gold.


I was gonna eventually move the single card over to a PC Power and Cooling 500W.  But I wanted to run it like this at first so I knew I wasnt having power problems.


My Windows rigs run 4 cards off the same Silverstone 1200W.  (Not the same same but same kind)  All of these PSUs are single rail.



One of my windows rigs was freezing up until I lowered the clocks and now it doesnt do it anymore.  Last night I lowered this 5 card BAMT rig down to almost stock clocks and it froze not even an hour after I went to bed.



When it freezes the fans are still on 100% you just cant wake the computer up and get the screen to come back on.  And its not mining because its not showing up on the pool and not blowing hot air out of the cards.

[MrBilling]

If you think 4 cards it too much for a 1200W maybe I should try 3 on one and 2 on the other.


Wierd though because my other rig runs strong with 4 cards on the same PSU.

[philips]

If you think 4 cards it too much for a 1200W maybe I should try 3 on one and 2 on the other.


Wierd though because my other rig runs strong with 4 cards on the same PSU.

Yes, try that.
Power the risers only from the main PSU (the one connected to the motherboard)

[MrBilling]

Well I hooked it up like you suggested.  I got 3 cards runnning off of one 1200W PSU, and the other 2 running off of another 1200W PSU.  I have the 2riser cables molex's plugged into the same PSU as the mobo.



It will run for a little while then freeze.  I have the clocks at stock.  My other BAMT rig runs 24/7 with alot stronger OC and mining settings.





A little later today when I get some time I may try to install BAMT to another USB stick and try that.

[MrBilling]

Hey Phillips.  Do you know if BAMT runs better or mor3 stable if it is ran headless?


Like if I turn the rig on with the screen hooked up long enough to get the local IP address from it then disconnect the monitor and run it from SSH after that.



Do you think this would make it run more stable?





Thanks