Rig with 4 GPU's, 2 fast, 2 slow

[Hi-Fish]

Hi

I' ve built a new 4 GPU rig and have a weird problem with it....

Hardware:

Mainboard= Asrock Z490 (I had a CPU for it lying around)
CPU= i5 10400
Ram= 2x4GB
PSU= 750W Corsair
GPU's= 4x Nvidia 1660 Super (2 onboard, 2 with riser)

Now my problem is that i've got hashrates around 27Mhs on 2 cards (one in #1 pci-e 16x onboard, one with riser) and only 20Mhs on the other 2 cards (one in #2 pci-e 16x onboard, one with riser).

Things i made/tried to solve the problem:

BIOS update
installed new nvidia driver, using DDU
installed new chipset driver
enabled/disabled above 4k decoding in the BIOS
tried different miners (Phoenix and t-rex)

Nothing changed... Any idea here in the forum?!?

Cheers Hi-Fish

PS: Temps are ok



 

[miner29]

try swapping a slow in place of a faster one. 

Does the problem follow the card or stay with the slot?

[Hi-Fish]

The problem stays with the slot(s)....

[miner29]

ok make sure you have the slots to gen2 and if it offers 8x/4x/4x in bios

Are you using any m.2 drives/devices as they use pcie lanes also and can be an issue.

[JayDDee]

Are all GPUs same brand and model with same specs?
Compare the clock, temp and voltage between the fast cards/slots vs slow.
It might be simpler to focus on 2 slots and rotate all cards through both slots
comparing all performance stats.

Try different algorithms to see if you get the same problem.

I assume you're using Windows. Try a live Linux mining OS to see if you get the
same results.

I find it bizarre that 2 x16 slots would perform so differently with the same card.
I also find it bizarre that 2 slots would underperform identically. Shared bandwidth
with other devices isn't usually an issue, x1 bandwidth is enough. I/O bandwidth isn't the
bottleneck with Eth anyway, it's mem bandwidth.

[Bitbtc8]

The problem stays with the slot(s)....

No it's not the slot......

OP download GPU-Z on your PC to detect the type of memory that those GPUs are using, this is the only way we can tell you the right settings for each, also download Msi Afterburner,

Open Msi Afterburner and downclock just like what you see in the image below



Power limit = 65%
Core Clock = -502
Memory Clock = -502
Fan speed = 57

This will drastically give you 30MH to 31MH per second on the graphic cards

Make sure your RAM is up to 4 gig size

[miner29]

Some responses missed that op moved cards and the problem stays at the slot...doesnt matter which cards are there.  See his response where he states the problem stays with the slot.  


OP - which os the exact model mobo you have ... there are severa asus Z490’s.

https://www.asus.com/us/site/motherboards/Intel-Z490/

[bobben2]

Hi

I' ve built a new 4 GPU rig and have a weird problem with it....

Hardware:

Mainboard= Asrock Z490 (I had a CPU for it lying around)
CPU= i5 10400
Ram= 2x4GB
PSU= 750W Corsair
GPU's= 4x Nvidia 1660 Super (2 onboard, 2 with riser)

Now my problem is that i've got hashrates around 27Mhs on 2 cards (one in #1 pci-e 16x onboard, one with riser) and only 20Mhs on the other 2 cards (one in #2 pci-e 16x onboard, one with riser).

Things i made/tried to solve the problem:

BIOS update
installed new nvidia driver, using DDU
installed new chipset driver
enabled/disabled above 4k decoding in the BIOS
tried different miners (Phoenix and t-rex)

Nothing changed... Any idea here in the forum?!?

Cheers Hi-Fish

PS: Temps are ok

If your BIOS has an  Above 4G decoding  then enable it and connect your display to the onboard HDMI/VGA/DP  (ie on the mobo).
Also, in the BIOS, see if there is an option to select 1st gen PCIE.  I think you would have better luck connecting all your GPUs via risers.  
If your mobo has more than 4 PCIe slots, then try to use any of the other slots.
You may also  want to disable ports not in use, ie  serial, parallel, even disable USB.  I once had a heck of a time with an AsRock  Fatality Z87 board.  I got it to work with 5 GPUs after a lot of trial and error.

[Hi-Fish]

No it's not the slot......

Open Msi Afterburner and downclock just like what you see in the image below

https://i.imgur.com/Bt098qo.png

Power limit = 65%
Core Clock = -502
Memory Clock = -502
Fan speed = 57

This will drastically give you 30MH to 31MH per second on the graphic cards

You sir are my helping hand! It works like a charm ! 

Thank you so much....

You also know good settings for 1070 cards?

Hi-Fish

[JayDDee]

Some responses missed that op moved cards and the problem stays at the slot...doesnt matter which cards are there.  See his response where he states the problem stays with the slot.  

That was the problem, everyone else believed it.

[Winscosinally]

No it's not the slot......

Open Msi Afterburner and downclock just like what you see in the image below



Power limit = 65%
Core Clock = -502
Memory Clock = -502
Fan speed = 57

This will drastically give you 30MH to 31MH per second on the graphic cards

You sir are my helping hand! It works like a charm ! 

Thank you so much....

You also know good settings for 1070 cards?

Hi-Fish

It depends on which brand of gtx1070 you have with you, use GPU-Z to check the memory type on the graphic cards, they have different settings for their mining sweet spot, mine is at

Core clock : +0
Memory clock : +800 mhz
Power limit : 60%

Some gtx1070 can't go over 800MHZ, some are stuck at 600mhz