Kaolo

The Paywall of PCI-E Bifurcation

PCI-E provides CPUs the ability to connect with fast devices, like >10 Gbps networks, NVMe SSD, etc. Especially for the usage of workstations or servers, the number PCI-E slots means a lot. As a result, Xeon CPUs and server-level MBs provide more PCI-E slots than on the consumer level. On the other hand, the number of PCI-E slots on cheap MB is usually only 1 for GPU. However, those server-level MBs are more expensive.
PCI-E bifurcation is an approach to split x16 PCI-E channels into different combinations, like 8+8 or 8+4+4. Since some PCI-E devices are only in x4 or x8 speed. But unlike AMD, Intel consumer-level MBs rarely offer such an option in the BIOS, let alone the lower-end products.
Note: PLX chips can also help you like a switch, but they are also expensive.
Bypass the paywall

Let’s do some hacking to bypass such paywall. My platform is Intel Core i5-3450 + Z77, but I guess this method is also useful for any Intel CPU with public datasheet information, like 12th gen CPU[3].
First, go to the Intel ark document webpage to check the “PCI Express Configurations”, which will show all bifurcation modes that your CPU supports.
For my CPU, 16=8+8=8+4+4, which provides the opportunity to place one x8 HBA card and 2 x4 NVMe SSD in one PCI-E slot! 
 

 
Second, get the datasheet of your CPU, and search for bifurcation-related content. You will find the config (CFG) to control PCI-E bifurcation.
note: the datasheet contains infos like the definitions of LGA1155, so that we can control it manaully.
 

 
As the fig above, the value of CFG[6:5] controls bifurcation modes on my platform, and:
00: 8+4+4 10: 8+8 11: 16 note: CFG[17:0] means 18 pins of LGA1155.
And then we search the positions of CFG pins to hard-set their values as we wish.


 
It shows that CFG[5] is N35, and CFG[6] is L37. So that we can find the actual physical position of CFG[5] and CFG[6].
 

 
As mentioned above, I want to set 16=8+4+4, so the values of CFG[5] and CFG[6] should be both 0. So we can ground CFG[5] and CFG[6] by connecting N35<->M35 and L37<->M37. (VSS is GND, and VCC is PWR)
I used some silver paste to make such hard strap.
 
 
 
Last, get a cheap PCI-E bifurcation card with clock MUX, like multiple NVMe SSD in one card.


 
my config places one LSI2308 with other NVMe SSDs in one PCI-E card. 
 

 
Now you can enjoy multiple devices with fast connections!
 
 
 
Small modification, big impact. So why MB producers disable this feature?
 
FYI: I tried to use AMIBCP tools to modify potentially hidden options in BIOS firmware, but sadly found nothing
 

I rarely ever come to the forums & even less do I answer to topics, but this caught my eye so bad.
 
How is it that you made the choice to use the term "Kung-flu" and not anything else like everyone else?
 
While not having to say the real name is no problem, using the term "Kung flu" seems to be extremely racist & discriminating and it's a shame to see this kind of language on this forum.
 
 

I rarely ever come to the forums & even less do I answer to topics, but this caught my eye so bad.
 
How is it that you made the choice to use the term "Kung-flu" and not anything else like everyone else?
 
While not having to say the real name is no problem, using the term "Kung flu" seems to be extremely racist & discriminating and it's a shame to see this kind of language on this forum.
 
 

I rarely ever come to the forums & even less do I answer to topics, but this caught my eye so bad.
 
How is it that you made the choice to use the term "Kung-flu" and not anything else like everyone else?
 
While not having to say the real name is no problem, using the term "Kung flu" seems to be extremely racist & discriminating and it's a shame to see this kind of language on this forum.
 
 

I rarely ever come to the forums & even less do I answer to topics, but this caught my eye so bad.
 
How is it that you made the choice to use the term "Kung-flu" and not anything else like everyone else?
 
While not having to say the real name is no problem, using the term "Kung flu" seems to be extremely racist & discriminating and it's a shame to see this kind of language on this forum.
 
 

????
It's a pandemic.
Also, this is the LTT forum, not YT monetization.
 
You can read about, or discuss the Covid-19 pandemic here ;
 

have you tried turning it on and off again?

Just use one usb drive, download both liliusb and the iso, follow the instructions.
When your usb key is ready, shutdown your computer, start it and boot from the usb key

Very useful, thanks!
I feel like you could add LightShot, which is way better than windows default screenshot tool. It's way faster to edit them also

I've had great luck with Anker for various cables and such in the past, and their USB hubs seem to be well liked on Amazon. I'd suggest checking those out.
I do have a 3xUSB 3.0 + Ethernet hub from Anker, (https://www.amazon.com/Anker-Portable-Ethernet-Network-Notebooks/dp/B014ZOJX7W/ref=sr_1_12?ie=UTF8&qid=1499829327&sr=8-12&keywords=anker+usb+3+hub) great quality, haven't had any issues with it yet, and I've had it for around 6-7 months now.
 
4 Port: https://www.amazon.com/Anker-4-Port-Macbook-Surface-Notebook/dp/B00XMD7KPU/ref=sr_1_2?ie=UTF8&qid=1499829327&sr=8-2&keywords=anker+usb+3+hub
7 Port: https://www.amazon.com/Anker-7-Port-Adapter-Charging-iPhone/dp/B014ZQ07NE/ref=sr_1_1?ie=UTF8&qid=1499829327&sr=8-1&keywords=anker+usb+3+hub