7x 5830 in 1 rig and GPUs only at 75% load

[MadHacker]

I have a problem with my mining rig.
I have 7 5830 saphire extream cards in 1 rig.
the motherboard is a P8P67 so 7 PCIe slots (4 16x, 3 1X)
Powersupply is a Antec AX1200 Single rail.

I have the cards set up to use PCIE cable extenders and the 3 1X cards are using 12v molex connectors on the extenders.

earlier today i only had 6 cards in the board and was running at 100%GPU load.
Power from the wall was 900 to 950W
adding the 7'th card dropped my GPU load to about 75%, this occurs even when running with stock settings.
however they are all mining.
I'm using CGminer as the mining software running in windows 7 64bit.

why is it only running at 75%.
I would like to get it up to 100% again.

any help on this would be great.


edit
using ATI 11.8 drivers

[mike678]

You only have 1 1200 watt psu for a 7x5830 rig?

[MadHacker]

You only have 1 1200 watt psu for a 7x5830 rig?

yes...
u think i need an extra PS? i have more lying around

[tritium]

what % is your CPU and how many cores/threads does it have? the catalyst driver has a CPU utilization problem

[mike678]

You only have 1 1200 watt psu for a 7x5830 rig?

yes...
u think i need an extra PS? i have more lying around

Each 5830 needs at least around 180 watts. 7x180=1,260 watts

That's before you take into account the rest of the rigs power needs. I'm almost positive its because you don't have enough watts. Try doing a dual power supply set up.

[Transisto]

first thing I though,  7x ,,,, What MOBO

It seems those card have 3 or two  PCI slot.

What version is it ?

[MadHacker]

first off the motherboard is a P8p67 ws revolution http://www.asus.com/Motherboards/Intel_Socket_1155/P8P67_WS_Revolution/
running with I3-2100 usualy set affinity to 1 core, but changing it to all cores make no difference.
i move one of the video cards to its own powersupply but made no difference at all. (runnig all cores)

[BkkCoins]

If your CPU utilization is high then try 11.6 drivers first. If that doesn't improve the GPU utilization then look at your power.

[MadHacker]

If your CPU utilization is high then try 11.6 drivers first. If that doesn't improve the GPU utilization then look at your power.

I tried using an extra 750W PS hooking up 2 video cards to it and I had no luck.
don't think its power since i have another almost identical machine but instead has 4 5830 and 1 6990
it pulls more power from the wall... 1050W on a 1200W PS. and it works fine.
i didn't try using 11.6 version of drivers.

I put the card in another machine and all is good for now..
I don't know of anyone else that has 7 5830 video cards running in a single machine.

[jjiimm_64]

I am back at the point where you said you had 7 GPU's running windows.  I thought the limit was 4 on windoz

[MadHacker]

I am back at the point where you said you had 7 GPU's running windows.  I thought the limit was 4 on windoz

use to be but with the 11.7 drivers the limit is now 8.
why they put a limit is beyond me...
they should just determine how many video cards there are and just allocate the memory for it.
so if you want a MB with 8 PCIE slots and 8 6990 video cards it would work... but no they don't do that.

[bulanula]

I thought the limit of GPUs was around 4 for Windows. Or maybe the 11.8 drivers took out this limit ?

[MadHacker]

I thought the limit of GPUs was around 4 for Windows. Or maybe the 11.8 drivers took out this limit ?

read post above.

[plastic.elastic]

If your CPU utilization is high then try 11.6 drivers first. If that doesn't improve the GPU utilization then look at your power.

I tried using an extra 750W PS hooking up 2 video cards to it and I had no luck.
don't think its power since i have another almost identical machine but instead has 4 5830 and 1 6990
it pulls more power from the wall... 1050W on a 1200W PS. and it works fine.
i didn't try using 11.6 version of drivers.

I put the card in another machine and all is good for now..
I don't know of anyone else that has 7 5830 video cards running in a single machine.

Does the other rig runs the same motherboard?
I suspect its the motherboard,

LOL at folks who thinks its the PSU. That AX1200 is plenty for this rig. I guess they follow that highly over requirement from ATi.....

[MadHacker]

Does the other rig runs the same motherboard?
I suspect its the motherboard,

LOL at folks who thinks its the PSU. That AX1200 is plenty for this rig. I guess they follow that highly over requirement from ATi.....

I have 4 identical motherboards running various video cards.

2 rigs running 4 6970 (Silver stone stider 1500w PS)
1 rig running 6 5830 (AX1200)
1 rig running 4 5830 & 1 6990 (AX1200)

my inital plan was to to build frames for the systems and then get 7 video cards in each machine
however now that the BC price has dorpped so much... i'm in no hurry to buy more video cards.

but would still 'like' to have as many cards in a single machine
if i can reduce my motherboard count by 1 then it would be some power saved.

[plastic.elastic]

Does the other rig runs the same motherboard?
I suspect its the motherboard,

LOL at folks who thinks its the PSU. That AX1200 is plenty for this rig. I guess they follow that highly over requirement from ATi.....

I have 4 identical motherboards running various video cards.

2 rigs running 4 6970 (Silver stone stider 1500w PS)
1 rig running 6 5830 (AX1200)
1 rig running 4 5830 & 1 6990 (AX1200)

my inital plan was to to build frames for the systems and then get 7 video cards in each machine
however now that the BC price has dorpped so much... i'm in no hurry to buy more video cards.

but would still 'like' to have as many cards in a single machine
if i can reduce my motherboard count by 1 then it would be some power saved.

You're truly going overboard with PSUs. But i  be its good investment and safe setup.

The last rig shows you have plenty of power for 7x 5830s. Its not the power issue, its rather the mobo or crappy extender.

I really think its the mobo. You can remove that 6990 with 2 x 5830s, i bet you would have the same issue.

I think the ceiling is 6 cards. Or you can shuffle the cards around to see if the order of slots matter. I wouldnt spend too much time tho. 6 cards are probably better for cooling and noise.