Adding more GPU makes the system see less GPU's

Mining
1

Hi everyone

Need a bit of help :slight_smile:

So i decided to upgrade my 4 gpu rig to 6 gpu rig,
My 4 gpu rig consist of:

1000 w PSU, 4 evga gtx 1070 sc 8 gb and Z170A gaming pro carbon motheboard.

I though - alright, I have 4 gpus on 1000 w, so let me add 2 more EVGA gpus and connect them to 550w, and use a splitter and verything will be great.

So everything just came with the post lady and I added the 550w PSU, connected them with the spiltter and added to 2 gpu’s to the new PSU and started up.

I saw 6 gpu’s and windows told me there where no resources for the 2 new ones.
Hmmm - rebooted and then my system only shows 3 gpus.

Disconnected the new psu and the new gpus, and my system shows 4 gpus again and are happy.

So - whats wrong here ? Did I make a mistake when ordering just a 550 w psu ?
My reasoning was just - hey 4 on 1000 w, then 2 extra on 550 w must be perfect :confused:

2

Try to uninstall the drivers, check if all the cards appear on the device manager and then reinstall the drivers

3

Hi Mineall

I thought about that - but in device manager it said that 2 of the cards ( the new ones added to the 550 w psu ) did not have enough resources, My big question is now: is a 550w too small ? :slight_smile:

4

When I’ve had a card say “Not enough resources”, I’ve found disabling the card and then re-enabling seems to help it out and initialized it.

Hope that helps.

5

I think the “not enough resources” message is referring to IO memory. Have you enabled 4G decoding in the motherboard bios? You need to do that for this many cards.

6

thanks alot for your help :slight_smile:
I went in to the bios and deactivated several things, and wupti, all 6 gpus are shown and have resources.

7

One wierd thing though

5 gpus are working at just about 400 sol/s while the 6th is at 250 sol/s - that is strange right ?

8

Open GPU Z and see if this 6th card is thermal or power throttling

9

Can you tell me what to look for ?

They have numbers really similair to each other.

Temperature is not the issue as the highest reported temp is 66 C and the lowest is 57.
All cards shows between 78% and 80 % TDP.

In after burner I have: Core +100, Mem +500 and Power 80%