Confusion between processor PCI lanes and motherboard PCI lanes

[nonono]

Hey!!!

I am bit confused about the difference between PCI lanes of PROCESSOR & MOTHERBOARD

Edited January 22, 2017 by Glenwing
Removed caps lock from title

[Guest Kloaked]

A CPU can support a maximum number of lanes. The motherboard actually has the lanes.

[knightslugger]

CPU lanes are wired directly to the PCIe slot.

 

MB lanes are wired to the CPU behind DMI.

[typographie]

I'm not sure what specifically you're confused about. The CPU lanes can be used at up to PCIe 3.0 16x, and on most motherboards are allocated to the full-length slots with locking mechanisms and usually used for graphics cards. Chipset lanes (on Skylake/Kaby Lake systems, anyway) are limited to PCIe 3.0 4x due to the speed of the connection between the chipset and CPU.

[manikyath]

a cpu has a number of direct pci lanes, the chipset has another number of lanes available, and the motherboard can choose to implement those in the way they see most fit.

[Mira Yurizaki]

Shameless plug.

[nonono]

2 minutes ago, Kloaked said:

A CPU can support a maximum number of lanes. The motherboard actually has the lanes.

i7 6700k has 16 pci lanes while gigabyte z170x gaming 5 motherboard 1x16, 1x8, 1x4, 2x M.2 & 3x Sata Express

[nonono]

3 minutes ago, typographie said:

I'm not sure what specifically you're confused about. The CPU lanes can be used at up to PCIe 3.0 16x, and on most motherboards are allocated to the full-length slots with locking mechanisms and usually used for graphics cards. Chipset lanes (on Skylake/Kaby Lake systems, anyway) are limited to PCIe 3.0 4x due to the speed of the connection between the chipset and CPU.

i7 6700k has 16 pci lanes while gigabyte z170x gaming 5 motherboard 1x16, 1x8, 1x4, 2x M.2 & 3x Sata Express

[nonono]

2 minutes ago, manikyath said:

a cpu has a number of direct pci lanes, the chipset has another number of lanes available, and the motherboard can choose to implement those in the way they see most fit.

i7 6700k has 16 pci lanes while gigabyte z170x gaming 5 motherboard 1x16, 1x8, 1x4, 2x M.2 & 3x Sata Express

[nonono]

4 minutes ago, knightslugger said:

CPU lanes are wired directly to the PCIe slot.

 

PCH lanes are wired to the CPU behind DMI.

i7 6700k has 16 pci lanes while gigabyte z170x gaming 5 motherboard 1x16, 1x8, 1x4, 2x M.2 & 3x Sata Express

[Guest Kloaked]

1 minute ago, dattharao said:

i7 6700k has 16 pci lanes while gigabyte z170x gaming 5 motherboard 1x16, 1x8, 1x4, 2x M.2 & 3x Sata Express

Read @M.Yurizaki's thread.

 

 

[manikyath]

1 minute ago, dattharao said:

i7 6700k has 16 pci lanes while gigabyte z170x gaming 5 motherboard 1x16, 1x8, 1x4, 2x M.2 & 3x Sata Express

and your mobo manual explains which are hooked up where.

[typographie]

Just now, dattharao said:

i7 6700k has 16 pci lanes while gigabyte z170x gaming 5 motherboard 1x16, 1x8, 1x4, 2x M.2 & 3x Sata Express

What you've listed there are just the physical slots Gigabyte chose to put on the motherboard. When we talk about "lanes" we mean the electrical connections between those slots and either the CPU or PCH that account for the amount of data bandwidth available to the device.

 

It's likely (read the manual) that the x16 slot receives all 16 lanes from the CPU, and the rest are wired to the chipset.

[nonono]

2 minutes ago, manikyath said:

and your mobo manual explains which are hooked up where.

My confusion is that 16 pci lanes provided by processor like core i7 6700k

Z170 chipset has upto 20 pci lanes

But the GIGABYTE z170x gaming 5 motherboard has 1x16, 1x8, 1x4, 2xM.2. 4x1 & 3 Sata express ports

one M.2 slot takes upto X4 pci lane

one sata express  take upto x4 pci lanes

so motherboard have total 52 pci lanes for all those connectors or something else

[nonono]

4 minutes ago, typographie said:

What you've listed there are just the physical slots Gigabyte chose to put on the motherboard. When we talk about "lanes" we mean the electrical connections between those slots and either the CPU or PCH that account for the amount of data bandwidth available to the device.

 

It's likely (read the manual) that the x16 slot receives all 16 lanes from the CPU, and the rest are wired to the chipset.

My confusion is that 16 pci lanes provided by processor like core i7 6700k

Z170 chipset has upto 20 pci lanes

But the GIGABYTE z170x gaming 5 motherboard has 1x16, 1x8, 1x4, 2xM.2. 4x1 & 3 Sata express ports

one M.2 slot takes upto X4 pci lane

one sata express  take upto x4 pci lanes

so motherboard have total 52 pci lanes for all those connectors or something else

[manikyath]

1 minute ago, dattharao said:

My confusion is that 16 pci lanes provided by processor like core i7 6700k

Z170 chipset has upto 20 pci lanes

But the GIGABYTE z170x gaming 5 motherboard has 1x16, 1x8, 1x4, 2xM.2. 4x1 & 3 Sata express ports

one M.2 slot takes upto X4 pci lane

one sata express  take upto x4 pci lanes

so motherboard have total 52 pci lanes for all those connectors or something else

the mobo manual, which i'm now referring to for the second time will explain you this.

for example, the 16x slot usually shares its lanes with the 8x slot, so if you use that 8x slot the 16x slot becomes an 8x slot, in a lot of cases its the same story for the 8x and 4x slot, and the rest of them are plugged into the chipset, which if they need to share connection, the mobo manual will explain you which and how.

[nonono]

13 minutes ago, manikyath said:

the mobo manual, which i'm now referring to for the second time will explain you this.

for example, the 16x slot usually shares its lanes with the 8x slot, so if you use that 8x slot the 16x slot becomes an 8x slot, in a lot of cases its the same story for the 8x and 4x slot, and the rest of them are plugged into the chipset, which if they need to share connection, the mobo manual will explain you which and how.

Please help me in understanding Page 18 of the manual of GIGABYTE Z170X GAMING 5 motherboard

[nonono]

24 minutes ago, typographie said:

What you've listed there are just the physical slots Gigabyte chose to put on the motherboard. When we talk about "lanes" we mean the electrical connections between those slots and either the CPU or PCH that account for the amount of data bandwidth available to the device.

 

It's likely (read the manual) that the x16 slot receives all 16 lanes from the CPU, and the rest are wired to the chipset.

Please help me in understanding Page 18 of the manual of GIGABYTE Z170X GAMING 5 motherboard

[nonono]

mb_manual_ga-z170x-gaming5_e.pdf

[NumLock21]

27 minutes ago, dattharao said:

My confusion is that 16 pci lanes provided by processor like core i7 6700k

Z170 chipset has upto 20 pci lanes

But the GIGABYTE z170x gaming 5 motherboard has 1x16, 1x8, 1x4, 2xM.2. 4x1 & 3 Sata express ports

one M.2 slot takes upto X4 pci lane

one sata express  take upto x4 pci lanes

so motherboard have total 52 pci lanes for all those connectors or something else

Your CPU has 16 and your chipset has 20, in total there are 36 lanes no more or less. There is no 52 lanes

1x16 = This first slot uses all 16 lanes only from your cpu

1x8 = This slot share the 16 lanes from your CPU and uses 8 of them. When you plug a card into this slot, the first slot (1x16) will drop down and run at x8.

1x4 = This slot uses 4 lanes from your chipset

2x M.2 = This just the number of M.2 connectors you have on your board, and it says you have 2 of them, each uses 4 lanes from your chipset.

4x1 = your board has 4 PCIe x1 slot, each uses 1 lanes from your chipset

3x SATA Express port = number of physical sata express ports you have, each takes up 4 lanes, so that's 12 from the chipset.

When you plug in certain devices other parts will turn off due to lack of PCIe lanes available. You can't run all of them at the same time. In some cases, depending on the board, it might reduce the lanes for a certain devices like your M.2 running at x2 instead of x4. Gigabyte knows what they are doing so no matter what, your board will not exceed the 20 lanes limit.

[nonono]

8 minutes ago, NumLock21 said:

Your CPU has 16 and your chipset has 20, in total there are 36 lanes no more or less. There is no 52 lanes

1x16 = This first slot uses all 16 lanes only from your cpu

1x8 = This slot share the 16 lanes from your CPU and uses 8 of them. When you plug a card into this slot, the first slot (1x16) will drop down and run at x8.

1x4 = This slot uses 4 lanes from your chipset

2x M.2 = This just the number of M.2 connectors you have on your board, and it says you have 2 of them, each uses 4 lanes from your chipset.

4x1 = your board has 4 PCIe x1 slot, each uses 1 lanes from your chipset

3x SATA Express port = number of physical sata express ports you have, each takes up 4 lanes, so that's 12 from the chipset.

When you plug in certain devices other parts will turn off due to lack of PCIe lanes available. You can't run all of them at the same time. In some cases, depending on the board, it might reduce the lanes for a certain devices like your M.2 running at x2 instead of x4. Gigabyte knows what they are doing so no matter what, your board will not exceed the 20 lanes limit.

Please help me in understanding Page 18 of the manual of GIGABYTE Z170X GAMING 5 motherboard and i also uploaded the manual

[typographie]

27 minutes ago, dattharao said:

Please help me in understanding Page 18 of the manual of GIGABYTE Z170X GAMING 5 motherboard

I believe that page is a series of tables showing what SATA ports are enabled/disabled when installing SSDs in certain configurations. For instance, if you install an M.2 SSD in PCIe mode (either 2x or 4x) in the M2H_32G slot, none of your SATA ports are disabled. Installing an M.2 SATA SSD in that slot disables the first SATA port.

 

You can just ignore SATA Express. You'll probably never see a SATA Express SSD as long as you live. SATA Express is the Betamax to M.2's VHS.

[nonono]

4 minutes ago, typographie said:

I believe that page is a series of tables showing what SATA ports are enabled/disabled when installing SSDs in certain configurations. For instance, if you install an M.2 SSD in PCIe mode (either 2x or 4x) in the M2H_32G slot, none of your SATA ports are disabled. Installing an M.2 SATA SSD in that slot disables the first SATA port.

 

You can just ignore SATA Express. You'll probably never see a SATA Express SSD as long as you live. SATA Express is the Betamax to M.2's VHS.

SATA EXPRESS drive will not come but sata port will become enable or disable

please help

[NumLock21]

1 hour ago, dattharao said:

Please help me in understanding Page 18 of the manual of GIGABYTE Z170X GAMING 5 motherboard and i also uploaded the manual

• The chart above only applies when you set your SATA controller in ACHI
• Title for the charts tells you the physical M.2 connector you're using
• Left side of chart, tells you the type of M.2 SSD you're using, that's SATA SSD, PCIe x4 SSD, or PCIe x2 SSD.
• Knowing what type of SSD you had buy, look at the chart on the left and then the right side tells you which SATA ports will work or not.

For example. you went out and got yourself a Samsung 960 Evo. Samsung 960 Evo is a pcie M.2 SSD that runs at PCIe x4. So when you install it, into M.2 label M2D_32G M.2 Connector, looking at the "PCIe x4 SSD", SATA Ports 0 to 3, will not work, Only SATA ports 4 and 5 will work.

 

 

Using the same as above, this only applies when you have set your SATA controller into RAID.

 

[nonono]

On 1/18/2017 at 11:20 PM, NumLock21 said:

• The chart above only applies when you set your SATA controller in ACHI
• Title for the charts tells you the physical M.2 connector you're using
• Left side of chart, tells you the type of M.2 SSD you're using, that's SATA SSD, PCIe x4 SSD, or PCIe x2 SSD.
• Knowing what type of SSD you had buy, look at the chart on the left and then the right side tells you which SATA ports will work or not.

For example. you went out and got yourself a Samsung 960 Evo. Samsung 960 Evo is a pcie M.2 SSD that runs at PCIe x4. So when you install it, into M.2 label M2D_32G M.2 Connector, looking at the "PCIe x4 SSD", SATA Ports 0 to 3, will not work, Only SATA ports 4 and 5 will work.

 

 

Using the same as above, this only applies when you have set your SATA controller into RAID.

 

Thank you very much for solving my problem