According to my latest messages, two MB's and another AM4 CPU will arrive today. Hope to have something useful to report on the original presenting question tomorrow! (How many gpus will a AM4 socketed motherboard run).

Tom

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A proud member of the OFA (Old Farts Association).

you can only get full 16x to slots 1,3,5,7. which is likely where you have all your cards plugged in.

slots 2,4,6 are only capable of 8x, if you look closely at the pictures you can see the [2,4,6] physical 16x slots are only electrically 8x, pins for lanes 9-16 are missing completely.

if you were to hypothetically run 7 GPUs on that board, you would be limited to 16x-8x-8x-8x-8x-8x-8x as per the manual.

if all of your GPUs are registering as PCIE gen 3 (8GT/s), then the PLX chips must be working on the CPU PCIE lanes only. research of the X99 block diagram is showing that the X99 chipset only provides 8 lanes of PCIe gen2. none at gen3.

Yes, I am running in those slots. Necessary for double-slot width cards. Just checked Nvidia X-server settings and all cards are running at PCIe Gen. 3 speeds at X16 lane width. Looked at the manual and you are correct with all slots populated, you are dropped to 16x-8x-8x-8x-8x-8x-8x. But we know with the Seti apps that lane width doesn't really effect the apps speed that much.

I know the dual PLX chips are working because until I repaired the motherboard, the bottom slots that were handled by the bottom PLX chip couldn't support any cards under load. Took me a day in troubleshooting to figure out what the problem was. Fixed, it is my most productive and stable system. My first foray into Intel hardware. I am impressed with the stability of this motherboard and cpu. I can't complain one bit. OK, maybe one, I wish I could run faster memory. I'm running 3000Mhz clocked memory and I think the system spec is only for 2400Mhz so still doing good. The cpu is only spec'd for 3.6Ghz but I have all cores running at 4250Mhz. Can't complain there either. I would recommend this board in a heartbeat to anyone running a 2011-V3 Intel chip. Much impressed.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

According to my latest messages, two MB's and another AM4 CPU will arrive today. Hope to have something useful to report on the original presenting question tomorrow! (How many gpus will a AM4 socketed motherboard run).

Tom

I think I may have a "hostile work environment." :/ The system booted once. Then the screen went black. When I restarted it the LED complains about bad this (reseat ram, reseat pcie devices, unplug usb devices [How am I supposed to do anything without the keyboard/mouse plugged in?}, reset cmos)that or the other thing. At least it is still booting.

That was last night. I will take another look today.

Tom

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A proud member of the OFA (Old Farts Association).

Finally got a working test bench after lots of DYI stupid tricks.

So far I have managed 4 gpus on a AM4 motherboard with 4 pcie slots and 2 non-pcie slots. This is using individual riser cards. I don't have the hardware adapters to see if I can add some gpu's via the m storage slots.

I may not get to anything until later Sunday evening. I have to verify the 5th GPU works before I try the 1 slot to 4 pcie expander again.

After this setup I have an x370 or something like that, that I will take another stab at because one the issues I was having had nothing to do with the MB.

Details at 11. :)
Tom

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A proud member of the OFA (Old Farts Association).

Semi-final results for an ASUS Prime B350 Plus.

Setup is 1600 watt psu, Ryzen 7 1700 running nearly stock bios settings. I bumped the memory speed to 3200/voltage to 1.35 and disabled to PSS (that is the speedstep on this brand of the bios).

It seems to be running reliably. I reset seti but am running it under an old (2990wx) computer id.

https://setiathome.berkeley.edu/show_host_detail.php?hostid=8606268

It will run upto 4 gpus (gtx 1060 3GB and/or 1 gtx 750Ti) using individual riser cards in the pcie slots. The MB has 4 pcie slots plus two other non-pcie slots.

It will not run more than 3 gpus if a 1 slot to 4 riser-card board is used.

I will order a 1 slot to 2 riser card board and see if I get different results.

That is why this is "semi-final" results.

Now that I have a working test bench I will go back and try to test a ASRock X470 Taichi MB next. It has 5 pcie slots and maybe an M.4 slot that I don't have the hardware to test.

Tom

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A proud member of the OFA (Old Farts Association).

Semi-final report on an ASROCK X470 Taichi.

This MB is running the same ram sticks as the previous test. It has an entirely different cpu a Ryzen 7 2700.

I was able to replicate the "I won't do more than 3 gpus" with the "known good, it runs 4 gpus on my Intel server" 1 slot to 4 pcie/usb connectors riser card. Sounds like I now have 2 or 3 reasons to get a 1 to 2 riser card/expansion card.

The thing that bothers me the most is this MB has 5 pcie slots. And I can't get it to recognize more than 4 gpus. It will boot with 5 gpus connected but "nvidia-smi" finds only 4 gpus. Yes they all crunch.
The MB clearly has 1 M.2 connector. So how is that being powered when I can't get 5 gpus to be recognized?

Tom

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A proud member of the OFA (Old Farts Association).

The current answer appears to be 4. Except someone reported 5 (but had stability issues) on a AX370-GAMING K7.

Tom

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A proud member of the OFA (Old Farts Association).

I had 5 on my Gigabyte AX370, but the problem I always have it keeping the risers seated properly in the slot. Likely it's just the brand I have now, I have new ones I want to try. Just the smallest little change in angle of seating makes a difference.

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I had 5 on my Gigabyte AX370, but the problem I always have it keeping the risers seated properly in the slot. Likely it's just the brand I have now, I have new ones I want to try. Just the smallest little change in angle of seating makes a difference.

I hope it works. It seems like there should be enough pcie lanes on the x370 MB's to make it work.

Its all those 14 gpu's Miner Rigs that are at fault for me wanting to see..... :)

Tom

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A proud member of the OFA (Old Farts Association).

A little while ago I googled "am4 mining board" and discovered there really was an AM4 socket motherboard out there with lots of pcie slots.

https://www.anandtech.com/show/11359/biostar-am4-mining-motherboards

Amazon has new and used ones in stock. Newegg was out of stock.

I have a "6 slot" AM4 socket mining motherboard on order.

I also have an Ryzen 7 cpu that I would dearly love to hang 6 or more gpus off of it.

Tom

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A proud member of the OFA (Old Farts Association).

A little while ago I googled "am4 mining board" and discovered there really was an AM4 socket motherboard out there with lots of pcie slots.

https://www.anandtech.com/show/11359/biostar-am4-mining-motherboards

Amazon has new and used ones in stock. Newegg was out of stock.

I have a "6 slot" AM4 socket mining motherboard on order.

I also have an Ryzen 7 cpu that I would dearly love to hang 6 or more gpus off of it.

Tom

Additional Notes:
If everything lights up but it won't boot, examine the "clear CMOS" jumper and make sure it is on 1-2 not 2-3 (on upper two pins not the lower two pins). I thought I got a new MB. But it was set for 2-3/Clear CMOS and would not boot.

The MB has had maybe 8-10 bios updates. You can do a "flash bios" update from F12 after you enable the "allow a bios update" in the Bios and save/reset that. Why is this important?
A reviewer on Amazon reported a long litany of workarounds to get most of the gpus working. And all those problems went away when he updated the bios. Right now I don't know if I am using the version he mentioned or not. But it is the "latest" bios update listed.

This box https://setiathome.berkeley.edu/show_host_detail.php?hostid=8684146 is currently running (right now) one gtx 1060 3GB (it was running two, until I started the MB swap).
Since this box also has an 750-850 PSU the next step is to swap in a 1600 PSU get all the powerlines sorted out and start reviewing the bios to find the "Upper 4G" pcie setting as well as disable the "cool 'n quiet" and the Cx settings. And make sure all the boost stuff is "on".

So at the earliest, I think I will have another report tomorrow.

Tom

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A proud member of the OFA (Old Farts Association).

A little while ago I googled "am4 mining board" and discovered there really was an AM4 socket motherboard out there with lots of pcie slots.

https://www.anandtech.com/show/11359/biostar-am4-mining-motherboards

Amazon has new and used ones in stock. Newegg was out of stock.

I have a "6 slot" AM4 socket mining motherboard on order.

I also have an Ryzen 7 cpu that I would dearly love to hang 6 or more gpus off of it.

Tom

Additional Notes:
If everything lights up but it won't boot, examine the "clear CMOS" jumper and make sure it is on 1-2 not 2-3 (on upper two pins not the lower two pins). I thought I got a new MB. But it was set for 2-3/Clear CMOS and would not boot.

The MB has had maybe 8-10 bios updates. You can do a "flash bios" update from F12 after you enable the "allow a bios update" in the Bios and save/reset that. Why is this important?
A reviewer on Amazon reported a long litany of workarounds to get most of the gpus working. And all those problems went away when he updated the bios. Right now I don't know if I am using the version he mentioned or not. But it is the "latest" bios update listed.

This box https://setiathome.berkeley.edu/show_host_detail.php?hostid=8684146 is currently running (right now) one gtx 1060 3GB (it was running two, until I started the MB swap).

Tom

Ok, without specifically enabling "above 4G" but where it mentions "mining mode" switching that to "VGA...above 4G" appears to have been the trick. For whatever reason "Mining mode 6x" stops at 4 gpus even with the pcie "Above 4G" is enabled.

I think I will let this run and see if it crashes.

If it doesn't crash, the next step is to install a 1 to 4 pcie expander card, some more power cables for the gpus and try for 7 or 8. I read in the Amazon Reviews someone managed to get 8 running, but said it was "finicky" :)

Opps, don't forget to install the GRUB command line patches.

Tom

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A proud member of the OFA (Old Farts Association).

Here is what the grub command line file should look like when you are "done."

Below are the steps to make the changes.

# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
#   info -f grub -n 'Simple configuration'

GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash pci=nommconf nomodeset"
GRUB_CMDLINE_LINUX=""

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console

You need to open a terminal command line session.

Then

tom@EJS-GIFT:~$ cd /etc/default
tom@EJS-GIFT:/etc/default$ sudo nano grub
[sudo] password for tom: 

This opens the grub file in a very simple editor called "nano".
You need to steer with the arrow keys but you can paste using the right click popup menu.
You need to use CNTL-O to write out the changes.  And CNTL-X to get out of nano.

tom@EJS-GIFT:/etc/default$ sudo update-grub
Sourcing file `/etc/default/grub'
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-4.15.0-46-generic
Found initrd image: /boot/initrd.img-4.15.0-46-generic
Found linux image: /boot/vmlinuz-4.15.0-45-generic
Found initrd image: /boot/initrd.img-4.15.0-45-generic
Found memtest86+ image: /boot/memtest86+.elf
Found memtest86+ image: /boot/memtest86+.bin
done
tom@EJS-GIFT:/etc/default$ 

This should fix a couple of "known" issues when you run a lot of gpus.

Tom

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A proud member of the OFA (Old Farts Association).

Ok, without specifically enabling "above 4G" but where it mentions "mining mode" switching that to "VGA...above 4G" appears to have been the trick. For whatever reason "Mining mode 6x" stops at 4 gpus even with the pcie "Above 4G" is enabled.

---edit---
Apparently it is "disable" the Mining mode and turn on the "above 4G" in the Pcie section.
You may need a cold boot to get it to recognize all 6
--edit--

I think I will let this run and see if it crashes.

If it doesn't crash, the next step is to install a 1 to 4 pcie expander card, some more power cables for the gpus and try for 7 or 8. I read in the Amazon Reviews someone managed to get 8 running, but said it was "finicky" :)

Opps, don't forget to install the GRUB command line patches.

Tom

Opps.

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A proud member of the OFA (Old Farts Association).

Ok, the current tentative answer is "6" with the right motherboard.

Tom

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A proud member of the OFA (Old Farts Association).

Ok, the current tentative answer is "6" with the right motherboard.

Tom

And 7 right now. 8 won't boot. Will take a stab at moving some cards around later. I also have a gtx 1070 I am going to replace one of the gtx 1060 3GB's with. I think I am going to have to buy some more riser cards if I want to run this one at high gpus and get my main box back up beyond 4 gpus.

Tom

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A proud member of the OFA (Old Farts Association).

Noticed the cpu wasn't running all that fast so jumped the multiplier 37. Had to jump the cpu voltage offset to something higher. It now is taking longer to crash. After 0.24 volts +, the scale goes yellow. At the 0.45+ offset the scale is red. I haven't seen a report of what the voltages are running at. May have to look around the bios again...

I also disabled the only place I could find a C1 report to OS.
I haven't found anything that might be the equivalent of the "cool 'n quiet" disable.

This would work much better with a miner's open case, though you would need an external startup button.

I am considering seeing how many gpus I can park on top of this "cube" case. It would free up table space for the other experiments. Maybe glue the video card bases to a light sheet of plywood. Since I have to keep the sides open for the cables, it doesn't matter if the top vents are closed.

Tom

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A proud member of the OFA (Old Farts Association).

Noticed the cpu wasn't running all that fast so jumped the multiplier 37. Had to jump the cpu voltage offset to something higher. It now is taking longer to crash. After 0.24 volts +, the scale goes yellow. At the 0.45+ offset the scale is red. I haven't seen a report of what the voltages are running at. May have to look around the bios again...

I also disabled the only place I could find a C1 report to OS.
I haven't found anything that might be the equivalent of the "cool 'n quiet" disable.

Got up due to insomnia and "it" is still running. So the last voltage offset did the trick. This looks like a production-level rig. Will play with moving the 1-4 pcie expander card around to see if I can get up to 8 gpus but I am not hopeful.

Tom

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A proud member of the OFA (Old Farts Association).

If you installed lm-sensors, you might be able to use sensors to report your cpu voltage level. Don't know anything about Biostar computers or which SIO monitoring chip they use. If it is a common one sensors should be able to poll it for current motherboards sensor readings.

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Seti@Home classic workunits:20,676 CPU time:74,226 hours

A proud member of the OFA (Old Farts Association)

Noticed the cpu wasn't running all that fast so jumped the multiplier 37. Had to jump the cpu voltage offset to something higher. It now is taking longer to crash. After 0.24 volts +, the scale goes yellow. At the 0.45+ offset the scale is red. I haven't seen a report of what the voltages are running at. May have to look around the bios again...

I also disabled the only place I could find a C1 report to OS.
I haven't found anything that might be the equivalent of the "cool 'n quiet" disable.

Got up due to insomnia and "it" is still running. So the last voltage offset did the trick. This looks like a production-level rig. Will play with moving the 1-4 pcie expander card around to see if I can get up to 8 gpus but I am not hopeful.

Tom

Nope, no joy on moving the 1 to 4 expander. Infact, it broke things. I finally got back to 6 gpus and have just discovered that one of my issues was a new to me gtx 1070 card that promptly shorted out.

And apparently there is no reliable bios settings to get 6 gpus running. You just have to start with the default 6X miners mode and keep trying till you get all of them working.

Tom

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A proud member of the OFA (Old Farts Association).