Awesome work. Please let the forum know the exact steps neccesarry. This may well be very helpful to enable bifurcation on "non bifuraction ITX Mainboards"Had success modding bios entries and bifurcating the last pci-e #5 slot on my motherboard by changing a few values in nvram. Only thing is I wish I could split down equally the channels to the M.2 onboard equally much like when you have two gpu's in slot 1 + 2 both know to operate at 4X. Unfortunately the way it is now if I enable both to PCI-E operation one shuts down. They must have a switch. So only way to get two NVME drives going is to use a two slot adapter and occupy the second slot with a pci-e m.2 adapter and forget about the onboard m.2 connector.
I wonder if the M.2 shares its lanes with the first 4 or last 4 lanes of PCIe Slot #5. Do you know?They must have a switch
I'm pretty sure its the last or second bus path that both m.2 and pci-e device share as indicated in the last image I posted. About the NVME drive yes its low profile. Its a Plextor AOC M8PEY drive and my case actually has a horizonal single slot mounting bracket built in positioned pretty much just 6 inches away from the pci-e slots. So this could work.I wonder if the M.2 shares its lanes with the first 4 or last 4 lanes of PCIe Slot #5. Do you know?
If it is the last 4 lanes it could work. If it is the first 4 you are out of luck in any way without a special riser. (This is probably the case, otherwise it would make no sense at all for MSI not to enable them both.) It would also explain the behaviour you were explaining.
Is your Slot NVME drive low profile? I could imagine a very simple riser putting the bottom 4 lanes top. I will probably send some new custom risers to fabrication in the near future so I could make one for you.
All in all very impressive work.
Step 1:Awesome work. Please let the forum know the exact steps neccesarry. This may well be very helpful to enable bifurcation on "non bifuraction ITX Mainboards"
Seems really groundbreaking,
Which picture? If that is really the case bifurcation should be visible in HWinfo when using the m.2 slot, even without your modification.I'm pretty sure its the last or second bus path that both m.2 and pci-e device share as indicated in the last image I posted.
So I take it it should be sufficient to modify the BIOS in amibcp and then load defaults?This of course is not permanent and a cmos reset will probably wipe this but its good for testing purposes before you flash your modded bios file you made earlier.
In post #609 I showed what it looks like for only the Plextor drive in Slot #5. It also looks the same for the onboard M.2 using the same bus port when that M.2 drive is set to PCIE Mode BUT the motherboard has a switch that completely turns off slot #5 when you do that. Is it because they’re using the same pcie port or bus? Will using a two slot Pcie riser adapter for the Plextor on alternate different bus or port allow simultaneous operation? I am inclined to believe that if I want to take advantage of all 8X lanes I would have to route both drives through the 8X pcie #5 slot. Cant use both at once. Furthermore in my experiments last night only certain IIO IOU2 variables needed to be set and the M.2 needed to be set to PCH Mode to bifurcate the 8X bus on Slot #5. Interestingly enough you could even bifurcate the M.2 bus when set to PCIE mode but it required all of IIOs to be set. So going to get that adapter maybe. Its $55 with shipping. See if I can truely bifurcate beyond HWinfo.Which picture? If that is really the case bifurcation should be visible in HWinfo when using the m.2 slot, even without your modification.
So I take it it should be sufficient to modify the BIOS in amibcp and then load defaults?
I've been using bifurcation for ~2 years now on my main PC, and trifurcation on a test PC, gotta say it's definitely the future.
Making a case for it, would love feedback from everyone in this thread: https://hardforum.com/threads/the-g-a4-layout-with-water-cooling-and-bifurcated-riser-15l.1948544/
Also planning a small version ~8L similar to DAN A4 with bifurcation.
That one wont do you no good as it bifurcates x16 into two x8.What model of Riser card is that??? Got in contact with Ameri-Rack. They recommend the ARC1-PERY423-C20. Is that it??
So I need a 8X to 4X4 split riser?? Do they even make one?? A 16X sized adapter won't be pin to pin compatible or backward compatible with a 8X Laned full size PCI-E Slot?That one wont do you no good as it bifurcates x16 into two x8.
I suggest you try that Fujitsu M.2Carrier Board D3352 with two m.2 slots I posted earlier.
If you wish I could design a custom riser for you, but it would be a waste if it wasnt working.
I will probably send out a new batch of risers soon so it would be OK price wise. Havent done M.2 so far however.
That one looks promising.Supermicro RSC-R2UU-2E4R 2U Right Slot 2x PCI-Express x4 + UIO Riser Card
Wow that looks cool. You should patent that design. How is it you can take it to fab? You own a company?That one looks promising.
As I said earlier I meant to add M.2 to my custom riser portfolio.
I took your efforts as motivation and this is what I came up with:
Sitting on the top will be the pcie slot for a low profile card.
I will send this to fab with some other order and see how it goes. I made quite a few experiments with this one (Lane Reversal, Lane Inversion, clock inversion, new M.2 Slot footprint, new card edge female connector footprint)
I will experiment and let you know. If they work I would gladly offer one to you.
Good point! However if you make these changes in BIOS they should survive a CMOS reset? No?Edit: Only one issue I can see causing a problem. That is the placement of the M.2 on the primary bus. I mean you want the drive that boots the OS on the first pci-e bus such that if theres a problem with the mod you don't lose your ability to boot into the OS. Unfortunately I have no idea which one that is. I would presume its the first quarter of the 16X physical slot.
That was my first idea of a "very simple riser" I was talking about. However its use would be only to some specific mobos and also I wanted to test my m.2 footprint.
I like your design as you could add a heatsink to your M.2 very easily. Right now my M.2 onboard is under my 2nd GPU so not sure if there would be room for a heatsink or fan placed over it.That was my first idea of a "very simple riser" I was talking about. However its use would be only to some specific mobos and also I wanted to test my m.2 footprint.
It would be much cheaper though... maybe I will do it too.
Sure... I have been giving them away against "donations" in the past so I can at least cover my expenses... 4 layer pcb's dont come cheap in low quantities... actually they are really expensive.Chris If your building a few of those can I make a donation for one?
Most of them are open drain so I can connect multiple endpoints.Just a little confused on how the pins before the keynotch such as the PRSNT1, SMCLK, + ClKREQ signals are routed with such an adapter and if it makes a difference whether a switch has shut off the first 4 lanes on the 8X slot?
Thank you. I'll tell you how I did it without getting too technical. Basically as you know I found out which variable in the Setup program was responsible for enabling bifurcation. These variables correspond to address locations and registers in the IntelSetup bios modules's memory space. I also used AMIBCP to change a few of the variable names on certain submenus that were hidden from view. For example there was one called PCI-E Lane Allocation or something with a '16/0' '8/8' selection choice. I revealed this hidden option by changing its access to 'USER' and found it useless causing my machine to lockup so I altered it to suit my needs. I renamed it 'Bifurcation support' and changed the '16/0' '8/8' to 'ON' + 'OFF'. From there I extracted the main Setup and Platform Bios efi driver modules using UEFITool. Setup module handled most of the common bios settings but there was the 'IntelRCSetup' category in AMIBCP.Awesome work! I am glad you are here.
Does this involve writing a custom efi module? Again I am very impressed and interested in how you achieved this.
I think I might donate one of my risers should they work.
First of all, great looking machine! Really gald everything worked out for you. Really making the most of your hardware!I am extremely happy to report that I was able to successfully bifurcate my 8X Slot into two!!!! Today the Supermicro RSC-R2UU-2E4R 2U arrived at long last and installed it with a 9 cm EZDIY Black X16 Riser cable:
I really didn't have to do anything beyond the modding I have already done. My bios automatically reset the onboard M.2 to PCI-E CPU operation where it was on the PCH before. I even benched both drives with AS-SSD and the scores were dramatically improved for the onboard M.2 as its now on the PCI-E highway.
Here are HWInfo64 images as proof:
The only thing that is a bother I guess is the green color of the Supermicro board and its handle! Also I found the EZDIY had a couple creases in it and not very flexible but not one bit of it went to waste. It fit perfectly onto the Slot and onto the Supermicro adapter.
This has got to be the most awesome mod ever! MSI said it couldn't be done and man were they so wrong!!!
Modding a laptop Bios is much more dangerous. You could end up with a brick. Usually those bios files are not standard and have protections and boot guard. But I have taken a look at them out of curiosity though I would never dare. At least with my machine I had a dual bios switch and a rom programmer just in case.First of all, great looking machine! Really gald everything worked out for you. Really making the most of your hardware!
Your work makes me curious what a laptop bios would look like under the hood. It makes me wonder if there would be certain options to add or unlock as OEMs like to keep most things pretty locked down.
Good to know, I'll be curious to look into it not that I'd do it myself more than likely. Thanks for the caution! Good luck with the build!Modding a laptop Bios is much more dangerous. You could end up with a brick. Usually those bios files are not standard and have protections and boot guard. But I have taken a look at them out of curiosity though I would never dare. At least with my machine I had a dual bios switch and a rom programmer just in case.
About what options there are check out Bios-mods.com. Lots of interesting unlocks for over clocking, Stuff like that.
Thanks for the compliment. Been wanting to water cool it next, got the parts, just not the time,
I had the same issue with a supermicro riser when I could only get gen2... Maybe it is hardware related? PCIe negotiates lower speeds when quality decreases.Had a WTF moment this morning. Besides my riser cable knocking the GPU fan ;( - the link speed dropped to 2.5 GT/S after making a minor bios setting change. Had to disable Bifurcation support. At that point the on-board M.2 disappeared. So I re-enabled my Bifurcation support bios mod option and rebooted back into Windows from the on-board M.2 and this time both were at 8 GT/s according to HWInfo. So it seems like weird things can happen but its working now like it should. This only proved that if anyone is looking to take advantage of their defunct last PCI-E slot when you've got a M.2 set to PCI-E mode your going to need to mod the bios...
Thats the best theory I have right now that its the riser cable not being the best quality maybe but honestly I have no idea. This has happened a few times on a warm boot. Sometimes turning off the bios settings on and off helps, sometimes not. Whats interesting is the L0s + L1 Exit Latency values are greater at 256-512 ns/32-64 us for the card on the riser adapter vs 2-4 us/32-64 us. I think that is the problem. The latency values need to be set correctly.I had the same issue with a supermicro riser when I could only get gen2... Maybe it is hardware related? PCIe negotiates lower speeds when quality decreases.
Looks great in any case. Maybe you could use some sort of an adapter or washer to counter balance the card attaching onto the case's screw holes.davidm71
OK.. got my low profile x8 -> x4 + M.2 Riser ready and tested.
PCIe working as expected.. polarity inversion on clock and data as well as lane reversal.
Also my M.2 socket footprint seems to be working perfectly.
Only thing I didnt get right is the height, so one cannot directly use the low profile bracket to screw into the full height slot as intended.
(I took the specified card height for low profile cards and not the slot height for my calculations which is obviously stupid)
Take a look. As always I have spare PCB's to sell should anyone be interested.
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