SM H12 New BIOS and IPMI Released

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MasterControl

New Member
Jan 15, 2023
11
5
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So I have an update, today SuperMicro sent me a BIOS with REBAR support to test for the H12SSL-i. Right now I am upgrading to it to verify it works for them, but I can confirm that REBAR support for this motherboard will be available soon!
Will be monitoring this thread closely... Hopefully Supermicro adds REBAR support for the H12DSi as well.
 

MasterControl

New Member
Jan 15, 2023
11
5
3
Its very strange but I just updated my BIOS to 2.7 and I no longer see VRM temps, nor any power usage or fan readings, in the BMC. I was on 2.4 before. Anyone know what's going on here?
wdk1190,

I am now running BIOS v2.7 and no issues to report. All temps/fan readings are reported correctly in the BMC.
 

noobsaibot

New Member
Mar 16, 2024
2
2
3
So I have an update, today SuperMicro sent me a BIOS with REBAR support to test for the H12SSL-i. Right now I am upgrading to it to verify it works for them, but I can confirm that REBAR support for this motherboard will be available soon!
I'm monitoring this as well as an owner of a H12SSL-NT and an Intel ARC A770 card. Arc cards perform much worse even on transcoding without access to SAM/ReBAR so I'm hoping it gets added to a future BIOS update. I've seen people using the ReBarUEFI project to add it that functionality to much older and lower spec'd motherboards including owers of Supermicro H11 boards. Unfortunately H12 boards added checks for signed bios updates and makes it harder than simply flashing through IPMI. I'm going to dig into it a bit more and see if I can flash it regardless but I would obviously prefer using an official bios.
 

vvkvvk

Member
Feb 1, 2023
82
31
18
If you use Linux you can just unbind the driver, raise up the BAR and it should be enabled; here's how my system does it with NVIDIA card on VM (/etc/libvirt/hooks/qemu.d/virt-instance/prepare/begin/bar.sh):

Code:
echo 0000:01:00.0 > /sys/bus/pci/devices/0000\:01\:00.0/driver/unbind
echo 0000:01:00.1 > /sys/bus/pci/devices/0000\:01\:00.1/driver/unbind
echo 13 > /sys/bus/pci/devices/0000\:01\:00.0/resource1_resize
echo "10de 2783" > /sys/bus/pci/drivers/vfio-pci/new_id
echo "10de 22bc" > /sys/bus/pci/drivers/vfio-pci/new_id
(You'd use your i915 or whatever the driver is and their paths and device IDs, mine are for 4070 super)
 

gnif

New Member
Feb 15, 2024
4
11
3
If you use Linux you can just unbind the driver, raise up the BAR and it should be enabled; here's how my system does it with NVIDIA card on VM (/etc/libvirt/hooks/qemu.d/virt-instance/prepare/begin/bar.sh):

Code:
echo 0000:01:00.0 > /sys/bus/pci/devices/0000\:01\:00.0/driver/unbind
echo 0000:01:00.1 > /sys/bus/pci/devices/0000\:01\:00.1/driver/unbind
echo 13 > /sys/bus/pci/devices/0000\:01\:00.0/resource1_resize
echo "10de 2783" > /sys/bus/pci/drivers/vfio-pci/new_id
echo "10de 22bc" > /sys/bus/pci/drivers/vfio-pci/new_id
(You'd use your i915 or whatever the driver is and their paths and device IDs, mine are for 4070 super)
No you can not, Intel screwed things up here.. On the PCIe bridge on the GPU, they decided to use the same 64-bit, prefetchable address space as the resizable GPU BAR itself and Linux PCI code won't move this resource to make room for the GPU BAR.

It is possible via a kernel patch, but it's a janky hack that causes other issues. The only real solution here is a BIOS from SuperMicro.

An update on this. I have the new BIOS, the new option is available however it causes the system to hang during post when rebar is enabled and any VGA device with rebar support is installed (Intel, AMD or NVidia). I am waiting for an update from SuperMicro at this time.
 

Gonkers

New Member
Mar 26, 2024
1
0
1
No you can not, Intel screwed things up here.. On the PCIe bridge on the GPU, they decided to use the same 64-bit, prefetchable address space as the resizable GPU BAR itself and Linux PCI code won't move this resource to make room for the GPU BAR.

It is possible via a kernel patch, but it's a janky hack that causes other issues. The only real solution here is a BIOS from SuperMicro.

An update on this. I have the new BIOS, the new option is available however it causes the system to hang during post when rebar is enabled and any VGA device with rebar support is installed (Intel, AMD or NVidia). I am waiting for an update from SuperMicro at this time.
Thank you for your diligence on this. I just picked up a H12SSL-i on ebay and have an Arc A380. The transcoding perf of the A380 is decent, but I don't want to leave perf on the table.
 

noobsaibot

New Member
Mar 16, 2024
2
2
3
I just checked back in on this thread and I couldn't have summarized it better myself. Thanks for following up on this and keep us posted on your bios adventures!

No you can not, Intel screwed things up here.. On the PCIe bridge on the GPU, they decided to use the same 64-bit, prefetchable address space as the resizable GPU BAR itself and Linux PCI code won't move this resource to make room for the GPU BAR.

It is possible via a kernel patch, but it's a janky hack that causes other issues. The only real solution here is a BIOS from SuperMicro.

An update on this. I have the new BIOS, the new option is available however it causes the system to hang during post when rebar is enabled and any VGA device with rebar support is installed (Intel, AMD or NVidia). I am waiting for an update from SuperMicro at this time.
 

learnedmachine

New Member
May 22, 2024
3
3
3
An update on this. I have the new BIOS, the new option is available however it causes the system to hang during post when rebar is enabled and any VGA device with rebar support is installed (Intel, AMD or NVidia). I am waiting for an update from SuperMicro at this time.
Hey, any update on this? I finally got around to trying to setup p2p on my GPUs and was massively disappointed to realize the board doesn't have resizeable bar support.