SXM2 over PCIe

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CyklonDX

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Nov 8, 2022
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I have a question. Since there is an Oculink connection on this GPU board, what are the two PCIe interfaces on it for? connect to motherboard pcie?
The PLX bridges are only visible over AOM-SXM-BRG connection.
@MildHotSauce hopefully can share his setup and thoughts in near future.
 

line

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May 13, 2023
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The PLX bridges are only visible over AOM-SXM-BRG connection.
@MildHotSauce hopefully can share his setup and thoughts in near future.
522232005.jpg

Will this device work properly if I connect these SFF 8611 links to the PCIe interface on the motherboard, insert a V100, and connect four power sources?
I bought the wrong connector wire. It should have been SF8611, but I accidentally bought SF8654 instead. That's why I'm asking.
 

CyklonDX

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Nov 8, 2022
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You need to connect either side or both (depending where the GPU's are connected). (purple or lime)
 
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gsrcrxsi

Active Member
Dec 12, 2018
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Interesting item. Other than being far too expensive for what it is, what do you lose by only having one of the SXM2 connectors on board rather than the two connectors on the GPU modules? 2x6-pin also seems like not enough power supply for most SXM cards in this class.
 

line

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May 13, 2023
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You need to connect either side or both (depending where the GPU's are connected). (purple or lime)
What wattage is your power supply? I seem unable to start without inserting the V100 using a 1250W power supply.
 

CyklonDX

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Nov 8, 2022
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Servers come in with 2kW PSU's and support up to 4 v100's.

I know that @MildHotSauce used ASUS Z790-P, not sure what PSU he used. He managed to get this working.
(I have some images of his setup, but i won't share unless he confirms its ok - but would be better if he posted them on his own.)
I think 1250W should be fine for 2 x V100's.
 

line

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May 13, 2023
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Servers come in with 2kW PSU's and support up to 4 v100's.

I know that @MildHotSauce used ASUS Z790-P, not sure what PSU he used. He managed to get this working.
(I have some images of his setup, but i won't share unless he confirms its ok - but would be better if he posted them on his own.)
I think 1250W should be fine for 2 x V100's.
After connecting the wires this way, the motherboard cannot detect the AOM-SXMV. I am not sure whether the GPU or the motherboard is faulty, or if there is a compatibility issue. Do I need the AOM-SXM-BRG? Can you help me identify the problem?
 

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gsrcrxsi

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Dec 12, 2018
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Are you using EPS (CPU) or PCIe (VGA) cables for the power connections? (I would assume they should be EPS connections)

have you tried swapping the order of the two PCIe data cables going to the PCIe slot on the motherboard?
 

line

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May 13, 2023
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Are you using EPS (CPU) or PCIe (VGA) cables for the power connections? (I would assume they should be EPS connections)

have you tried swapping the order of the two PCIe data cables going to the PCIe slot on the motherboard?
I used PCIe cables for power connection, but I changed the wiring sequence, and I also tried swapping the order of the two PCIe data cables going to the PCIe slot on the motherboard. However, it didn't work, as the motherboard couldn't detect any device connected to the single PCIe interface.

So I'm confused. Could it be that the GPU or motherboard was damaged before changing the power cables?

1685646024450.png GPU borad power supply,


1685646062592.png PCIE 8Pin power supply,
I swapped the wire sequence.
 

line

New Member
May 13, 2023
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Are you using EPS (CPU) or PCIe (VGA) cables for the power connections? (I would assume they should be EPS connections)

have you tried swapping the order of the two PCIe data cables going to the PCIe slot on the motherboard?
Before swapping the wire sequence, I attempted to power on the system but it did not boot up. I am concerned that this may have damaged the GPU motherboard.
 

gsrcrxsi

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Dec 12, 2018
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It’s possible the GPU was damaged yes. Impossible to know for sure unless you had a known working system to put it into and test it.
 

CyklonDX

Well-Known Member
Nov 8, 2022
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After connecting the wires this way, the motherboard cannot detect the AOM-SXMV. I am not sure whether the GPU or the motherboard is faulty, or if there is a compatibility issue. Do I need the AOM-SXM-BRG? Can you help me identify the problem?
where heatsink at? | and you didn't connect your pcie port... (the lack of bridge pcie port won't prevent you from booting the system - but you will need it -ex. you can use this sc raiser SUPERMICRO RSC-G-6 to connect that pcie with your motherboard pcie)
1685651254716.png


the power connectors should be your 12V 8-pin GPU power supply connectors. (std pcie connectors)
 
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gsrcrxsi

Active Member
Dec 12, 2018
312
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where heatsink at? | and you didn't connect your pcie port... (the lack of bridge pcie port won't prevent you from booting the system - but you will need it -ex. you can use this sc raiser SUPERMICRO RSC-G-6 to connect that pcie with your motherboard pcie)
View attachment 29325


the power connectors should be your 12V 8-pin GPU power supply connectors. (std pcie connectors)
agree on the lack of heatsink, but I’m a little confused by what you mean about the bridge connectors being required. The first few posts in this thread seem to be saying that the whole idea of this is to circumvent those connectors completely (you said they kept dying, leading you to use the oculink ports instead). Is that not correct?

if the bridge connections are truly required and you can’t use the cable connections solely, this seems like a non-starter for getting this board on a different system. Those bridge connections, while electrically look to be PCIe, are physically non-standard and I don’t think an adapter for them exists. Unless you can link to one. if you mean for the SUPERMICRO RSC-G-6 you referenced to accomplish this, it wont physically fit on the AOM-SXMV. it will impinge on the GPUs.

and the manual seems to indicate that the power connections are 12V EPS (CPU) connections. not standard VGA PCIe connections (based on the pinout). enterprise GPUs tend to use EPS connectors (4x 12v, 4x gnd) not the PCI connectors (3x 12v, 5x gnd, flipped orientation)
 
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