PCIE Bifurcation

C_Payne

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You could try using a cheap card that has only 8 or 4 lanes and see if it boots, or isolate the last 8 lanes on your gpu with some tape.
But you can also go ahaed and order the splitter.
Ebay steals 10% ... thats why they cheaper in my shop.

My preference would be to bifurcate at the mainboard and use 2 cables from there. This may however only work with one of the bigger tops on this case. Not sure about the clearance there...
Use this one:
https://peine-braun.net/shop/index.php?route=product/product&path=65_59&product_id=68

If you have a better idea let me know, and I will make a custom one for you. Custom ones are more expensive though as I have to pay around €100 for the PCBs alone, add the hours of designing the PCB.
 

C_Payne

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ChronoDog
JokinenK
I also have news concerning the low profile x8x8 Splitter for the NCase M1:

It all seems to just barely fit together: I will make an x8x8 version first, and if it works the x8x4x4 with M.2 will follow on demand.
It will be a tad bit more expensive as the angled slots are €15 a piece without tax alone and the cradle mount slots are a pain to solder.

Bildschirmfoto von 2019-11-03 14-52-04.png

marcosscriven
This could also be an option four your case?!?
 
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News flash - found a combination that worked.

1. Download A40vA6 2019-03-07 - the version just before Ryzen 3 / Zen 2 support http://download.msi.com/bos_exe/mb/7A40vA6.zip
2. Modify as per this thread
3. Flash from a flash utility of your choice (M-FLASH on BIOS will refuse to downgrade)

This time choosing the 2x8 option does the right thing!

I see one extra (rather than three extra) PCI bridges:

Code:
00:01.1 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) PCIe GPP Bridge
00:01.3 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) PCIe GPP Bridge
00:03.2 PCI bridge: Advanced Micro Devices, Inc. [AMD] Family 17h (Models 00h-0fh) PCIe GPP Bridge
And the GPU negotiating the right speed:

Code:
LnkSta: Speed 8GT/s (ok), Width x8 (downgraded)
 
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So C_Payne - I just need to choose one of your splitters, and a second GPU! Thanks for your help.

This one: https://peine-braun.net/shop/index.php?route=product/product&path=65_59&product_id=68 looks like it would point upwards in my case, and as I don't want a top hat, I don't think that would work.

In the YouTube video I linked, he uses that one, but at the bottom. However, he can do so as he's used custom water blocks to make both GPUs single slot.

So that's one option.

Another is to get a 'mini' or 'itx' GPU leaving space nearer the front, like MaximumBurrito did here https://hardforum.com/threads/pcie-bifurcation.1870298/page-12#post-1042880213

But if I don't want a top hat, that needs a different splitter.

The NCase one you linked might work - not quite sure how that orients?
 
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As an aside - MSI support hinted they may fix this officially (even though I have it working for a modded older BIOS now):

Reply: 2019-11-04 15:51:49

Yes, we have duplicated the issue and we will fix it in new bios vA.B, please pay attention to the BIOS version at MSI Website, after we release the bios vA.B, please update the BIOS for a try.
 
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So I think I've settled on the two GPUs I think will work in the Ghost S1:

1. A small passively cooled 1030 to serve as a decent 4k @ 60Hz desktop GPU (essentially to replace the missing aGPU in the Ryzen) - https://www.msi.com/Graphics-card/GeForce-GT-1030-2GH-LP-OC/Specification
2. A mid-range GTX for use either in the host (via bumblebee) or in the guest (via passthrough) https://www.gigabyte.com/uk/Graphics-Card/GV-N166TIXOC-6GD/sp#sp

Here's a (pretty terrible) photo marked up to show where they'll go. The 1660 gets the official slot - the 1030 will be oriented veritcally, and I'll have to have a right angle HDMI coming out of the top, and routed to the back of the case. The PCI connector of the smaller GPU would be on its left side, next to the other GPU.

WhatsApp Image 2019-11-04 at 14.19.14.jpeg



You can see how the riser angles over the top to plug into the motherboard - I'd rather be able to keep that as is if possible, as the GPU slot screws into the case spine, and supports the card. Changing that would having to find another fixing.

C_Payne would any of your splitters work? I think I've got about 10mm from the side of the existing socket on the mobo, to the top of the case.
 
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C_Payne

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yes it needs BIOS support. It will look similar, but has an additional M.2 Slot. It will of course need Bios support.
The slots look different, because one is a right angled one and one is a craddle mount style.
 

JokinenK

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ChronoDog
JokinenK
I also have news concerning the low profile x8x8 Splitter for the NCase M1:

It all seems to just barely fit together: I will make an x8x8 version first, and if it works the x8x4x4 with M.2 will follow on demand.
It will be a tad bit more expensive as the angled slots are €15 a piece without tax alone and the cradle mount slots are a pain to solder.

View attachment 197126

marcosscriven
This could also be an option four your case?!?
This looks awesome and just what I need!

Can you give some rough estimate of the price with shipping to Finland?
 

C_Payne

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I am planning to sell it for €80
20€ more than usually because of the super expensive angled slot, and the painful assembly process.
 
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yes it needs BIOS support. It will look similar, but has an additional M.2 Slot. It will of course need Bios support.
The slots look different, because one is a right angled one and one is a craddle mount style.
Is there any way to make the part that slots into the main PCIE flexible in some way? Or is that just a case of having a super short riser cable?
 

C_Payne

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Is there any way to make the part that slots into the main PCIE flexible in some way? Or is that just a case of having a super short riser cable?
I am personally not manufacturing with cables, as it requires a lot of expensive tools and is a pain to do.

You could use a small 5 cm ribbon in combo with this one: https://peine-braun.net/shop/index.php?route=product/product&path=65_59&product_id=68
to offset the outputs a bit to the CPU. Signal strength will suffer though due to the additional connector and cable.

I think the Ncase M1 one may just work for you.

A third option is a complete custom one.
 
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I am personally not manufacturing with cables, as it requires a lot of expensive tools and is a pain to do.

You could use a small 5 cm ribbon in combo with this one: https://peine-braun.net/shop/index.php?route=product/product&path=65_59&product_id=68
to offset the outputs a bit to the CPU. Signal strength will suffer though due to the additional connector and cable.
I've gone ahead and ordered this one from your shop, as hoping it'll be more flexible for future projects. Do you happen to recommend a supplier for 5cm risers? If not I'll have to find on on eBay I guess.

I love the idea of custom, but image that's a lot of work and cost of producing a one-off.
 
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C_Payne - will the splitter work with one GPU that only has a x4 connection?

I bought a GT 1030 and when BIOS is in default 1x16 mode, it only negotiates at x4.

I subsequently read up on this, and it's just how that model is designed (and looking at the board in hand, you can see only the traces nearer the ports end of the board are wired up).

When I turn on bifurcation mode (without the split) I see no output at all at the moment, with just this GPU. Wondering if that'll be fixed when I use the splitter?
 

C_Payne

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Yes x4 should work without issues.

As for the missing Output my only idea is that your firmware has BIOS Compatibility enabled and doesn't open the VGA BIOS when bifurcation is enabled. Try disabling CSM and run UEFI only.
 
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Yes x4 should work without issues.

As for the missing Output my only idea is that your firmware has BIOS Compatibility enabled and doesn't open the VGA BIOS when bifurcation is enabled. Try disabling CSM and run UEFI only.
I don’t think it’s just no output in the BIOS, as it doesn’t proceed to boot either.

Will try as you say though. The splitter may arrive today so can hopefully try this out.

EDIT - Package status only just says 'leaving Germany' as of this morning. so I guess not.
 
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ChronoDog

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ChronoDog
JokinenK
I also have news concerning the low profile x8x8 Splitter for the NCase M1:

It all seems to just barely fit together: I will make an x8x8 version first, and if it works the x8x4x4 with M.2 will follow on demand.
It will be a tad bit more expensive as the angled slots are €15 a piece without tax alone and the cradle mount slots are a pain to solder.

View attachment 197126
This looks very promising, and the price you're asking for is very fair.

So, if I understand correctly, the idea is to use this riser in conjunction with a short (5-10cm) ribbon riser for the GPU?
This seems to be a rather narrow fit behind the graphics card, and require a steep bend on the cable.
Wouldn't in be better/cleaner to make the angled slot face downward, towards the motherboard?

As this kind of riser is only really necessary for ITX boards to begin with, I think it'll render the fact that it'll be harder to use on other form factors in such a configuration irrelevant anyway.
 

C_Payne

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Hello, has anyone had experience using this motherboard ASRock X399 PHANTOM GAMING 6 https://www.asrock.com/MB/AMD/X399 Phantom Gaming 6/ will x8x8 risers work on it
Couldn't find any info myself, however as it is physically possible you may as well try and if there is no option for x8x8 ask asrock to implement the feature in their BIOS. I assume they will have at least x4x4x4x4 support already.


This looks very promising, and the price you're asking for is very fair.

So, if I understand correctly, the idea is to use this riser in conjunction with a short (5-10cm) ribbon riser for the GPU?
This seems to be a rather narrow fit behind the graphics card, and require a steep bend on the cable.
Wouldn't in be better/cleaner to make the angled slot face downward, towards the motherboard?
There is no "left angled" slots to buy anywhere. also the available space would be too little. The PCBs came today and I will keep you posted. I have found a special ribbon cable that has the cable soldered 180deg. See picture. 15735853495926287600438998022804.jpg
 

JokinenK

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I want one, to be continued in PM.

EDIT: Can't send PM, so do I order from your site as well if I want the cable with it?
 

JokinenK

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Sent message and ordered one! Do you happen to know where I could possibly source the metal adapter bracket you posted in previous page?
 

C_Payne

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I disassembled it from another card: a startech pcie to pci adaptor
They are a bit expensive though, but my other customer insisted on spending it.
 

JokinenK

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Will do, most likely it will arrive next year if the history repeats itself, but when it does I will report back.
 

ChronoDog

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Also C_Payne, would it be possible for you to make this (https://peine-braun.net/shop/index.php?route=product/product&path=65_61&product_id=63) riser with the slots reversed, 8x4x4x instead of 4x4x8x? On top of that which motherboards support this riser?

I'm working on a case, that supports far too many expansion slots for ITX boards. And your risers have me pipe dreaming. Right now I've got an M.2 riser to low profile off the back of the board + planning a 8x8x bifurcation riser with 1 + 2 slot physical spacing but wondering if I should just support your 8x4x4x risers too. Because watercooling cards to make them single slot is too much fun.
 

C_Payne

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TheArkratos sorry for getting back to you late!
Question 1: I have yet to find a GPU that uses a significant amount of 3.3V so if using 2 GPUs additional 3.3V won't be necessary. This will likely be the same for most cards. M.2 SSDs will use 3.3V though.
Sata can provide 12V 4.5A which is just a bit shy of the 5.5A of a PCIe slot. PCIe Power or EPS would be better, however I am going the SATA way because one may not have a free GPU or EPS connector.

Question 2: I can gladly make a custom one for you. Due to the high PCB setup costs its a bit more expensive though.
Itx Mainboards I know of with x8x4x4 support:
Asrock Z370, z390, x99, x299 gigabyte x570
 
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TheArkratos sorry for getting back to you late!
Question 1: I have yet to find a GPU that uses a significant amount of 3.3V so if using 2 GPUs additional 3.3V won't be necessary. This will likely be the same for most cards. M.2 SSDs will use 3.3V though.
Sata can provide 12V 4.5A which is just a bit shy of the 5.5A of a PCIe slot. PCIe Power or EPS would be better, however I am going the SATA way because one may not have a free GPU or EPS connector.

Question 2: I can gladly make a custom one for you. Due to the high PCB setup costs its a bit more expensive though.
Itx Mainboards I know of with x8x4x4 support:
Asrock Z370, z390, x99, x299 gigabyte x570
Thanks for the info. For now I'll build the case with your 8x8x adapter, but in the future swapping to a 8x4x4x riser would be as simple as making a new internal bracket. You do good work C_Payne, I'm excited for the riser, should be way more flexible to use than the amerirack one I've had for a few years now.

I still really want to see someone make a case for this riser you made: https://peine-braun.net/shop/index.php?route=product/product&path=65_59&product_id=55
 
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So I've finally got bifurcation working thanks to C_Payne

However, now I've hit another issue - the plan all along was to passthrough the second GPU to a VM, but it turns out that both GPUs now appear in the same IOMMU group!

Does anyone know then if this fundamentally won't work?

Code:
IOMMU Group 2:
    00:03.0 Host bridge [0600]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse PCIe Dummy Host Bridge [1022:1482]
    00:03.1 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse GPP Bridge [1022:1483]
    00:03.2 PCI bridge [0604]: Advanced Micro Devices, Inc. [AMD] Starship/Matisse GPP Bridge [1022:1483]
    0a:00.0 VGA compatible controller [0300]: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere [Radeon RX 470/480/570/570X/580/580X/590] [1002:67df] (rev e7)
    0a:00.1 Audio device [0403]: Advanced Micro Devices, Inc. [AMD/ATI] Ellesmere HDMI Audio [Radeon RX 470/480 / 570/580/590] [1002:aaf0]
    0b:00.0 VGA compatible controller [0300]: NVIDIA Corporation GP108 [GeForce GT 1030] [10de:1d01] (rev a1)
    0b:00.1 Audio device [0403]: NVIDIA Corporation GP108 High Definition Audio Controller [10de:0fb8] (rev a1)
 
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