M.2 Sata/NVME Graphics card help.

[blinky2015]

Hi

I am a amateur when it comes to building pcs but its something that always interested me so I had ago about 2months ago:

I have a Asus crosshair vi hero motherboard and a MSI 1080 gpu.

I installed windows on this M.2 drive:
https://www.overclockers.co.uk/wd-blue-250gb-m.2-2280-6gbps-solid-state-drive-wds250g1b0b-hd-53k-wd.html

After only finding out the other day that you get sata and nvme ones i have a sata one and have read the nvme as so much faster/better choice etc.
Now after reading further into it i see that a nvme shares lanes with the gpu? i dont really understand this part.

So my question is basicly would i have any problems getting a M.2 nvme and running with my motherboard and gpu?

And if anyone wouldnt mind explaining the lanes etc to me in dummbie terms that would also be great.

Thanks Link

 

[Traditore]

When the computer starts up, PCIe determines which devices are plugged into the motherboard. It then identifies the links between the devices, creating a map of where traffic will go and negotiating the width of each link. Each lane of a PCI Express connection contains two pairs of wires -- one to send and one to receive. A x1 connection, the smallest PCIe connection, has one lane made up of four wires. It carries one bit per cycle in each direction. A x2 link contains eight wires and transmits two bits at once, a x4 link transmits four bits, and so on.

The CPU has x16 PCIe 3.0 lanes, specifically used in the PCIe x16 slots. The motherboard chipset has another PCIe 3.0 lanes, some of which are dedicated to the M.2 socket when it is used. An M.2 drive on the motherboard will be able to get the full performance.

Sharing of PCIe lanes means that when too many devices are connected - beyond the provided number of lanes of CPU+MB, the lanes will be shared, and videocard x16 will work in x8 lanes mode, transferring less data in order to provide lanes for other devices.

But you will have to fill all your PCIe slots (with like 2 videocards, gigabyte network cards, SSDs) for this to start happening.

 

[unclebun]

The WD Blue M.2 SSD uses the SATA III 6Gb/s interface. This is the same interface that you connect mechanical hard drives to with a SATA cable, and its speed is 6 Gb/second. SSD's are capable of faster data transmission than the SATA system can transmit. So another transport system was devised, NVMe, which uses the PCI-e bus, which is capable of 63 Gb/s in the x16 lane. At first this meant the SSD was on a PCI-e card and went in the PCI-e slot instead of a video card. But the M.2 interface gets around that. M.2 slots can be either SATA or NVMe.

Your motherboard supports NVMe only with a Ryzen cpu, not with A-Series. Its specs say it supports PCIe 3.0 in x4 mode for NVMe. In PCIe 3.0, each lane supports 985 MB/s, so x4 would be four times that, or 3.94 Gb/s.

 

[geofelt]

I would not bother.

While you could replace your sata mode m.2 device with a pcie device, do not get too excited about any performance increase.
It will come mostly from sequential operations such as virus scans.
In most of what you do, it is the small random I/O latency at low queue depths that matters most.
That is what windows does mostly.

The latency of all current ssd devices is remarkably similar.
When OPTANE or Z-SSD devices arrive that will be a big change.

 

[drajitsh]

1. I disagree with geofelt. one the USP of NVMe was reduced latency over AHCI.
2. the quantum of improvement of PCIe/NVMe drives over a decent SATA drives with much less than the improvement of SSD over HDD. the perceptible difference in normal client workloads is even less.
3. Your motherboard is Ryzen(AM4), in mainstream platforms, the CPU has 16+4 lanes. The 16 lanes go to your GPU, you HDD/ sata ssd/ NVMe sd DOES NOT INTERFERE with that.
4. the remaing 4 lanes go to the chipset and everything other than the GPU hangs off that. If you put a FAST NVMe drive (read samsung), & it is reading sequentially at high queue depth then it can interfere with your USB 3.1, Gigabit LAN, very high bit rate audio, thunderbolt --if you have it.
5. However, if you use a PCIe to M2 adaptor and put that in the 2nd x16 slot, then in certain RARE situations you MAY affect the GPU performance.

 

[blinky2015]

Thanks all for you help and advice, I feel I understand it a bit more but I'm still unsure weather its a better idea to do or not?
I use it mainly for gaming so the last thing I want to do is affect my GPU but like the idea of a lot fast loading and boot times etc.
To me it sort of just sounds like I'm limiting my M.2 through sata?

Geofelt mentioned Optane /z-ssd which is completely new to me aswell so ive done a bit of reading up and watched a few videos stating there isnt much difference between them and better off as a "addon" for a HDD? I think... hope that makes sense?.

@ Drajitsh I was actually think of getting a:
https://www.scan.co.uk/products/500gb-samsung-960-evo-v-nand-m2-nvme-pcie-gen-30-x4-3200mb-s-read-1800mb-s-write-330k-330k-iops
This certain one would possibly cause a problem?

Thanks again Link

 

[geofelt]

If budget is not an issue, go ahead and buy the Samsung 960 evo pcie drive.
It is excellent.

As to worth, that is something only YOU can determine.
In actual use, you are not likely to see anything magical.
I did not when I changed from sata to pcie.

 

[blinky2015]

Thanks again!
cool ill go get one tomorrow, as back to the bit I don't understand if I was to get another 1080 and sli would I then have a problem?