6700k PCIE Lanes Limitation? 6700k+SLI

[Mgibbs829]

Hey Guys,

 

I have a question. I currently have a 6700k on a Gigabyte Gaming 7 z170x board.

 

I am upgrading to 2x gtx1080s. I have some questions about the PCIE lanes. I have a samsung 950 PRO NVME SSD.

 

Will 2x1080+the NVME drive work? I know that is exactly 20 lanes.

 

Also will that disable ALL my sata ports? I have a 2.5 inch ssd and a mechanical hard drive as well.

 

Thanks for the help LTT Forums!

 

Matt

[done12many2]

1 minute ago, Mgibbs829 said:

Hey Guys,

 

I have a question. I currently have a 6700k on a Gigabyte Gaming 7 z170x board.

 

I am upgrading to 2x gtx1080s. I have some questions about the PCIE lanes. I have a samsung 950 PRO NVME SSD.

 

Will 2x1080+the NVME drive work? I know that is exactly 20 lanes.

 

Also will that disable ALL my sata ports? I have a 2.5 inch ssd and a mechanical hard drive as well.

 

Thanks for the help LTT Forums!

 

Matt

 

It will work just fine.  The 1080s will use PCIe lanes from the 16 available CPU lanes and the NVMe will use lanes from the 20 available chipset lanes.

[iiNNeX]

I have 2x 1080s in SLI and a 950 Pro. I have no problem with the system running at full tilt, and in every benchmark where SLI results are shown I score just as high or higher as a 40 lane CPU. 

[Rickie cheong]

25 minutes ago, iiNNeX said:

I have 2x 1080s in SLI and a 950 Pro. I have no problem with the system running at full tilt, and in every benchmark where SLI results are shown I score just as high or higher as a 40 lane CPU. 

Wait, I thought that it has only 16 PCIe lanes, how come you can still run a m.2 950 pro

[done12many2]

Just now, Rickie cheong said:

Wait, I thought that it has only 16 PCIe lanes, how come you can still run a m.2 950 pro

 

Look two posts up.

[BeeBee8]

On 31/08/2016 at 10:32 PM, iiNNeX said:

I have 2x 1080s in SLI and a 950 Pro. I have no problem with the system running at full tilt, and in every benchmark where SLI results are shown I score just as high or higher as a 40 lane CPU. 

Hey ! Are you sure ? Because 6700k has only 16 CPU lanes. What I've learned is that the 20 lanes from PCH is by DMI 3.0 link and it is slower than 950 pro resulting in bottleneck. I'm planing to build a PC with 1080s in SLI and got confused about the lanes in z170 series

[done12many2]

11 minutes ago, cbhhargava said:

Hey ! Are you sure ? Because 6700k has only 16 CPU lanes. What I've learned is that the 20 lanes from PCH is by DMI 3.0 link and it is slower than 950 pro resulting in bottleneck. I'm planing to build a PC with 1080s in SLI and got confused about the lanes in z170 series

 

DMI 3.0 will only reach saturation with 2 or more 950 Pro M.2 SSDs in a RAID 0.  One 950 Pro will be able to operate at full speed without a "bottleneck".

[BeeBee8]

1 minute ago, done12many2 said:

 

DMI 3.0 will only reach saturation with 2 or more 950 Pro M.2 SSDs in a RAID 0.  One 950 Pro will be able to operate at full speed without a "bottleneck".

According to the above diagram DMI 3.0 has 20 PCIe lanes at 8Gbps but 950 pro can go upto 20 Gbps. I don't understand how it doesn't bottleneck. Can you explain ? 

Because if it really doesn't bottleneck, I can save a lot of bucks with skylake instead of broadwell-e  

 

[done12many2]

18 minutes ago, cbhhargava said:

According to the above diagram DMI 3.0 has 20 PCIe lanes at 8Gbps but 950 pro can go upto 20 Gbps. I don't understand how it doesn't bottleneck. Can you explain ? 

Because if it really doesn't bottleneck, I can save a lot of bucks with skylake instead of broadwell-e  

 

 

DMI 3.0 has just under 4 GB/s (3.93GB/s theoretical) of throughput.  A Samsung 950 Pro M.2 SSD (512 GB variant)  can deliver 2.5 GB/s sustained read and 1.5 GB/s sustained write.  Like I said, one drive will not completely saturate DMI 3.0, but 2 or more in RAID 0 will.

 

I've time stamped this video for you, but go back and watch the whole thing when you have more time.

 

 

 

[BeeBee8]

1 hour ago, done12many2 said:

 

DMI 3.0 has just under 4 GB/s (3.93GB/s theoretical) of throughput.  A Samsung 950 Pro M.2 SSD (512 GB variant)  can deliver 2.5 GB/s sustained read and 1.5 GB/s sustained write.  Like I said, one drive will not completely saturate DMI 3.0, but 2 or more in RAID 0 will.

 

I've time stamped this video for you, but go back and watch the whole thing when you have more time.

 

 

 

Awesome. Your the man! 

Also found this http://www.myce.com/review/native-z170-hyper-m-2-vs-pcie3-m-2-77791/synthetic-benchmarks-2/

This article compares M.2 attached to native M.2 slot which is behind DMI and an M.2 which is attached directly to CPU using a PCIe adapter and there isn't any noticeable change. Thanks man.

[AlphaPolack]

On 8/31/2016 at 0:26 PM, Rickie cheong said:

Wait, I thought that it has only 16 PCIe lanes, how come you can still run a m.2 950 pro

Z170 provides 20 PCIe lanes, 8x,8x,4x in his configuration

[Rickie cheong]

On 9/14/2016 at 4:19 AM, AlphaPolack said:

Z170 provides 20 PCIe lanes, 8x,8x,4x in his configuration

i thought it was 16?

[done12many2]

1 hour ago, Rickie cheong said:

i thought it was 16?

 

CPU = 16 lanes

Z170 chipset = 20 lanes. 

 

Hope that helps. 

[Rickie cheong]

oh,thanks

[Drak3]

On ‎8‎/‎31‎/‎2016 at 11:00 AM, done12many2 said:

 

It will work just fine.  The 1080s will use PCIe lanes from the 16 available CPU lanes and the NVMe will use lanes from the 20 available chipset lanes.

That depends on how the manufacturer routes the lanes. On my X99 board, the M.2 runs off of the CPU's native lanes, leaving the chipset's alone.

[done12many2]

6 minutes ago, Drak3 said:

That depends on how the manufacturer routes the lanes. On my X99 board, the M.2 runs off of the CPU's native lanes, leaving the chipset's alone.

 

The thread is about a z170 platform.  My x99 does the same thing as yours.

[Drak3]

Just now, done12many2 said:

 

The thread is about a z170 platform.  My x99 does the same thing as yours.

You have to look at the specific board in question, since manufacturers are free to route PCIe as they wish. Since Gigabyte doesn't seem to reveal the routing online, I can't say that Gigabyte isn't running the M.2 off of the CPU's lanes. It would make sense to us that the M.2's be ran off the chipset, but that doesn't always matter.

[done12many2]

Just now, Drak3 said:

You have to look at the specific board in question, since manufacturers are free to route PCIe as they wish. Since Gigabyte doesn't seem to reveal the routing online, I can't say that Gigabyte isn't running the M.2 off of the CPU's lanes. It would make sense to us that the M.2's be ran off the chipset, but that doesn't always matter.

 

Gigabyte, along with every other z170 board manufacturer routes the native onboard M.2 slots through the chipset and DMI 3.0.  

 

Which z170 board did you find contrary to that fact?

[Drak3]

Just now, done12many2 said:

 

Gigabyte, along with every other z170 board manufacturer routes the native onboard M.2 slots through the chipset and DMI 3.0.  

 

Which z170 board did you find contrary to that fact?

I don't recall the specific board name, but it's a first wave Gigabyte Z170 ultradurable, with features resembling that of which you'd find in a basic workstation in the office. It's one I picked up when I had to upgrade my dad's PC.

[done12many2]

7 minutes ago, Drak3 said:

I don't recall the specific board name, but it's a first wave Gigabyte Z170 ultradurable, with features resembling that of which you'd find in a basic workstation in the office. It's one I picked up when I had to upgrade my dad's PC.

 

Let me know when you find the name since you brought the subject up.  I'm interested.

 

 

[DrM]

On Tuesday, September 13, 2016 at 11:16 AM, cbhhargava said:

According to the above diagram DMI 3.0 has 20 PCIe lanes at 8Gbps but 950 pro can go upto 20 Gbps. I don't understand how it doesn't bottleneck. Can you explain ? 

Because if it really doesn't bottleneck, I can save a lot of bucks with skylake instead of broadwell-e  

 

thats 8gb per x1 lane. the 950 uses x4 lanes, so it has 32gb of bandwidth

[Drak3]

3 hours ago, done12many2 said:

 

Let me know when you find the name since you brought the subject up.  I'm interested.

 

 

Searching for the specifics of that board isn't something I really care about. It's likely discontinued and I didn't keep the box or documentation.

If you don't believe me, oh well. It's not that important, and you're right that most of Intel's 100 series chipset equipped boards run M.2 slots on the DMI's PCIe lanes. Wouldn't surprise me if all the ones currently available do.

[NumLock21]

2 minutes ago, Drak3 said:

Searching for the specifics of that board isn't something I really care about. It's likely discontinued and I didn't keep the box or documentation.

If you don't believe me, oh well. It's not that important, and you're right that most of Intel's 100 series chipset equipped boards run M.2 slots on the DMI's PCIe lanes. Wouldn't surprise me if all the ones currently available do.

your dad's build has, why not just tell us the board model.

[Drak3]

Just now, NumLock21 said:

your dad's build has, why not just tell us the board model.

Multiple reasons

A) I don't care about having to prove myself. It's not like I know any of you, and I'll probably forget that this forum exists in a week.

B) I don't have access to that build anymore, and there is no reason for me to have access to it.

C) The point of the thread is whether it's possible to run 2 1080s and a x4 M.2 in a system. The point of my post is that mainboard manufacturers can route lanes as they need and/or want.

 

I never said it isn't possible. If the board has 2 x16 slots and an M.2, it'd be pretty stupid if they weren't all usable if the resources are there. All I said is that manufacturers can and have routed differently from what makes sense to us.

[NumLock21]

1 minute ago, Drak3 said:

Multiple reasons

A) I don't care about having to prove myself. It's not like I know any of you, and I'll probably forget that this forum exists in a week.

B) I don't have access to that build anymore, and there is no reason for me to have access to it.

C) The point of the thread is whether it's possible to run 2 1080s and a x4 M.2 in a system. The point of my post is that mainboard manufacturers can route lanes as they need and/or want.

 

I never said it isn't possible. If the board has 2 x16 slots and an M.2, it'd be pretty stupid if they weren't all usable if the resources are there. All I said is that manufacturers can and have routed differently from what makes sense to us.

Can't prove yourself, then stop pulling info out of thin air, unless you can back them up. Did a bit of background search. All M.2 for Z170, runs off the chipset, CPU lanes are dedicated to the main x16 slots.