Would an NVMe SSD affect my GPU?

[monkeymanz]

I haven't built my PC yet, but I'm planning on running a Skylake I7 6700k on an ASUS z170-AR motherboard with a GTX 970. However, I'm also thinking of putting a Samsung 950 Pro on there, but I don't know if the x4 PCIe lanes that are used up by the ssd will reduce the performance on my graphics card, since the CPU only supposedly supports 16x PCIe lanes. So what I'm asking is, will using a Nvme ssd use up the x16 lanes on my motherboard?

Also, is paying almost double the price worth it for an NVMe SSD, or will i just be better off with a SATA ssd like the 850 evo? I plan on using the PC for mainly gaming, rendering and a bit of content creation, with the SSD only being used for applications and not personal files.
Thanks

 

[Karadjgne]

I'd stick with a regular Sata SSD. The NVMe's are really only for performance freaks, benchmark junkies and those select few who run programs that definitely benefit from 1000/1000 r/w speeds vrs regular Sata 500/500. Considering the realistic speeds of even a sata SSD, doubling the r/w speeds isn't near as big a performance increase like SSD vrs HDD. And even though SSDs do have some impact on gaming, its not even close to enough to warrant NVMe speeds. Not sure how it would affect content creation, but rendering is more cpu oriented than anything else and should easily be handled by a regular Sata SSD.

Most boards that I can think of share pcie lanes with the secondary pcie x16 slot and/or x1 slots, not the primary x16, better cpus like the 6700 having more than 20 pcie Lane capability, so no, gpu performance wouldn't be touched except for possibly sli/CF or even tri-sli/cf

 

[ko888]

The M.2 socket on that motherboard shares PCIe lanes with the PCIe x16_3 slot and SATA6G_56 connectors. Those PCIe lanes are connected to the PCIe 3.0 bus on the Intel Z170 chipset.

The two graphics card slots PCIe x16_1 and PCIe x16_2 lanes are connected to the PCIe 3.0 bus that is connected to the CPU socket.

The M.2 socket will not be using any of the PCIe lanes that are being used for the graphics cards.

NVMe is designed specifically for use by SSDs because of its high bandwidth and low latency. AHCI is inefficient compared to NVMe.

 

[cst1992]

I have a Z97-A motherboard, and if I'm not mistaken, the Z97-AR is similar in functionality.

If you want to have a M.2 SSD, get the M.2 version of the 850 Evo. Similar in performance and uses SATA, but it's M.2.

If you install a 950 Pro, you'll be limited to 800MB/s max throughput(10Gbps - overhead of PCI-e 2.0 x2) as the M.2 slot shares bandwidth with the two PCI-e x1 slots.
You'll not get full 950 Pro speed as it's 32Gbps(3.0x4) and that motherboard supports 10Gbps(2.0x2). But it'll still be way faster than a 850 Evo.

 

[Leaps-from-Shadows]

Wow the misinformation in this thread...

On a Z170 board, there is zero chance of an M.2 drive reducing graphics performance.

The CPU has 16 PCIe 3.0 lanes, specifically used in the PCIe x16 slots. The Z170 chipset has another 20 PCIe 3.0 lanes, four of which are dedicated to the M.2 socket when it is used. An M.2 drive on Z170 will be able to get the full performance listed -- in the case of the 950 Pro, that's 2200/900 for the 256GB drive and 2500/1500 for the 512GB drive.

Samsung 950 Pro 512GB performance on my Z170 system:

And as far as PCIe performance goes...

Theoretical performance of one PCIe 3.0 lane is 10Gbps. With overhead, it's slightly less than 8Gbps. When you see a mainboard manufacturer claim 32Gbps for the M.2, they are combining all four PCIe 3.0 lanes together -- 8x4=32.

The chipset that has PCIe 2.0 x2 lanes for the M.2 is Z97. M.2 drive performance will be limited on those boards, unless they use a PCIe 3.0 x4 to M.2 adapter card.

 

[cst1992]

The 20 lanes are combined, not in addition to CPU.
What is the user going to do with 36 lanes? Not to mention a Z170-based CPU won't yet support it. For that kind of rig, the E series is released(2011, 2011-v3 socket so far, I'm sure a Skylake-based one will be coming soon).
My hunch is that the extra 4 lanes were added because of PCI-E based storage support.

 

[Leaps-from-Shadows]

The 20 lanes are combined, not in addition to CPU.
What is the user going to do with 36 lanes? Not to mention a Z170-based CPU won't yet support it. For that kind of rig, the E series is released(2011, 2011-v3 socket so far, I'm sure a Skylake-based one will be coming soon).
My hunch is that the extra 4 lanes were added because of PCI-E based storage support.

No. Not combined. The user doesn't get to choose where to provision them -- the mainboard manufacturer does that. And the chipset's PCIe lanes have their own controller -- the CPU only controls its own PCIe lanes.

Read the block diagrams in this link (click the spoiler) and be amazed. Z170 is a huge boost over all previous chipsets.

 

[cst1992]

I'd like to believe that. I really would. But look at a typical Z170 motherboard:
https://www.asus.com/in/Motherboards/Z170-PRO-GAMING/specifications/

If you look at the specs of the Z97 Pro Gamer, which is this board's Z97 counterpart:
https://www.asus.com/in/Motherboards/Z97PRO_GAMER/specifications/

you'll see that the only difference is the left-most x16 slot, which supports only 2.0 on the Z97, whereas 3.0/2.0 on the Z170. That indicates to 20 PCI-e 3.0 lanes. If that is the board the customer buys, he's only got 20 lanes to use. Maybe the M.2 slot has its own 4 lanes, maybe not.

 

[Leaps-from-Shadows]

Where do you think the 10Gbps bandwidth for the USB 3.1 comes from? That looks like two PCIe 3.0 lanes to me (two USB 3.1 at 10Gbps each equals two PCIe 3.0 lanes, since PCIe 2.0 can only do 5Gbps).

And they advertise 32Gbps for the M.2 -- that's four PCIe 3.0 lanes right there.

That's more than four, no matter "what you'd like to believe".

Some reading for you:
Z97 versus Z170
Comparison of 100-series chipsets
Z97 chipset on Intel's site
Z170 chipset on Intel's site

 

[monkeymanz]

Wow the misinformation in this thread...

On a Z170 board, there is zero chance of an M.2 drive reducing graphics performance.

The CPU has 16 PCIe 3.0 lanes, specifically used in the PCIe x16 slots. The Z170 chipset has another 20 PCIe 3.0 lanes, four of which are dedicated to the M.2 socket when it is used. An M.2 drive on Z170 will be able to get the full performance listed -- in the case of the 950 Pro, that's 2200/900 for the 256GB drive and 2500/1500 for the 512GB drive.

Samsung 950 Pro 512GB performance on my Z170 system:

And as far as PCIe performance goes...

Theoretical performance of one PCIe 3.0 lane is 10Gbps. With overhead, it's slightly less than 8Gbps. When you see a mainboard manufacturer claim 32Gbps for the M.2, they are combining all four PCIe 3.0 lanes together -- 8x4=32.

The chipset that has PCIe 2.0 x2 lanes for the M.2 is Z97. M.2 drive performance will be limited on those boards, unless they use a PCIe 3.0 x4 to M.2 adapter card.

Thanks for the help. It all makes sense now.
Since you have a 950, would you recommend paying more money for its real world improvement over a normal ssd?

 

[Leaps-from-Shadows]

I've had a Crucial MX100 512GB, a Samsung 840 Pro 256GB, and now the Samsung 950 Pro 512GB. Is there a real-world difference? Yes, but it's small. My system is overall quicker in its everyday tasks than it was, but the difference isn't anywhere near what the huge benchmark numbers suggest.

If you're using drive-heavy applications, definitely get the 950 Pro.
For any other usage, the extra performance isn't worth it. Just get a bigger SATA SSD, like a 1TB 850 EVO.

 

[cst1992]

Have you ever used a SATA based M.2 SSD? Does the M.2 interface make any difference to performance?

 

[Leaps-from-Shadows]

No I haven't. But if it's using the SATA protocol, then it will perform like a SATA drive. It will just be neater because you won't have to use cables for power or the interface.

 

[malessandro]

Hello,

I really try to understand PCIe Lanes and how to calculate the available slots for my needs (wishes).

I am planning with the MSI X99A Godlike Gaming Carbon and the i7-6850K.

I want to add my GTX 980Ti and a Samsung SM961 1TB M.2. Also I am planning to get the upcoming Samsung 960 Pro.

I could put the SM961 in the M.2 slot of the motherboard and since there is only one M.2 slot I could put the 960 Pro in an PCIe slot with an adapter.

Does that make any sense?

 

[Leaps-from-Shadows]

Hello,

I really try to understand PCIe Lanes and how to calculate the available slots for my needs (wishes).

I am planning with the MSI X99A Godlike Gaming Carbon and the i7-6850K.

I want to add my GTX 980Ti and a Samsung SM961 1TB M.2. Also I am planning to get the upcoming Samsung 960 Pro.

I could put the SM961 in the M.2 slot of the motherboard and since there is only one M.2 slot I could put the 960 Pro in an PCIe slot with an adapter.

Does that make any sense?

Other than the SM961 and the 960 Pro being identical (the 961 is the OEM version of the 960 Pro), it does make sense. Do you really need both SSDs?

The GPU needs 16 lanes and each SSD needs 4 lanes. That's 24 lanes total, so you could even have another 16-lane GPU for SLI with no problems.

 

[malessandro]

I didn't know that they are identical. I'm not sure if I need both, really. I want one to boot from and having my software installed on. And maybe one to work on. Like caching simulations (Autodesk Maya, Houdini etc). I read a lot of reviews and tests on a lot of those relatively new M.2 SSDs and the SM961 got my interest due to price and capacity. And the upcoming 960 Pro might have some better heat management plus direct warranty from samsung.

On the other hand one of them could possibly be a "normal" SSD SATA with ~500MB read/write.

Thank you for explaining the lanes to me!

 

[Dogbites]

I haven't built my PC yet, but I'm planning on running a Skylake I7 6700k on an ASUS z170-AR motherboard with a GTX 970. However, I'm also thinking of putting a Samsung 950 Pro on there, but I don't know if the x4 PCIe lanes that are used up by the ssd will reduce the performance on my graphics card, since the CPU only supposedly supports 16x PCIe lanes. So what I'm asking is, will using a Nvme ssd use up the x16 lanes on my motherboard?

Also, is paying almost double the price worth it for an NVMe SSD, or will i just be better off with a SATA ssd like the 850 evo? I plan on using the PC for mainly gaming, rendering and a bit of content creation, with the SSD only being used for applications and not personal files.
Thanks