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General Forums => Hardware and Software => Topic started by: Ramesis on August 22, 2019, 02:20:02 PM

Title: nvme vs pcie
Post by: Ramesis on August 22, 2019, 02:20:02 PM
I am looking to build a new gaming box but I am a little confused
about the M.2 SSDs.
As I understand it, there are 2 types of M.2 sticks... Pcie and nand
From what I have read, I'm pretty sure I want to go with the pcie stick
BUT I am confused about the number of lanes it uses and whether or not
that will interfere with the performance of the GPU
I will be using the i9-9900k cpu and cannot decide on a MoBo until I
settle this issue
Can anyone clear this up for me because I cannot find any site with a
definite conclusion?
Ram

Title: Re: nvme vs pcie
Post by: TequilaChaser on August 22, 2019, 02:32:15 PM
So you are concerned that if you used one of your pcie x16 slots, if it will affect the other(s) where your GPU is attached?

Generically speaking, yes it will drop the pcie x16 slots to x8

There are other options, but to give you the most correct answer, you should post your components that you are using and wanting to add/use

Edit: I just re-read your post, sorry, I didn't pick up that you are building from scratch basically


Hope this helps

TC
Title: Re: nvme vs pcie
Post by: AAIK on August 22, 2019, 03:26:19 PM
Sorry if this is a little long, but you might find something enlightening:

https://www.youtube.com/watch?v=u1lSIg2lxTg
Title: Re: nvme vs pcie
Post by: TequilaChaser on August 22, 2019, 05:49:14 PM
Ramesis,

I take it, that you already have the 9-9900k cpu , correct?

Do you already have your GPU? If so,  let us know what model it is and some of us can design you a system around what ever parts/components and Case if you already have that too....

Telling us what you already have along with what other components you desire/want, will help others design you a long dependable computer build

Hope this helps

TC
Title: Re: nvme vs pcie
Post by: mikeWe9a on August 22, 2019, 09:48:05 PM
While it depends on how the motherboard is set up, typically your GPU uses 16 PCIE lanes directly to the CPU.  Additional PCIE lanes are provided by the motherboard chipset, and are used for such things as your NVME storage.

Mike
Title: Re: nvme vs pcie
Post by: Chalenge on August 22, 2019, 11:53:12 PM
You are restricted to 16 lanes altogether. Your GPU really only needs 8 lanes (x8). I tested x16/x16 versus x8/x8 and found a (perhaps) 1% advantage to x16/x16, while a single card sometimes gave the advantage to the x8 setup, but only by a single frame per second.
Title: Re: nvme vs pcie
Post by: Ramesis on August 23, 2019, 09:28:00 AM

So you are concerned that if you used one of your pcie x16 slots, if it will affect the other(s) where your GPU is attached?

Generically speaking, yes it will drop the pcie x16 slots to x8

There are other options, but to give you the most correct answer, you should post your components that you are using and wanting to add/use

Edit: I just re-read your post, sorry, I didn't pick up that you are building from scratch basically

Hope this helps

TC

Yes I am building from scratch... I am planning on using only one PCIex16 slot and that will be whatever GPU I settle on

Ramesis,

I take it, that you already have the 9-9900k cpu , correct?

Do you already have your GPU? If so,  let us know what model it is and some of us can design you a system around what ever parts/components and Case if you already have that too....

Telling us what you already have along with what other components you desire/want, will help others design you a long dependable computer build

Hope this helps

TC

Yes, I already have the i9-9900k (I always build around my selected cpu)
I also already have the case (corsair 750d), the power supply (corsair 1200i) and a Corsair H100i cooler

Sorry if this is a little long, but you might find something enlightening:

https://www.youtube.com/watch?v=u1lSIg2lxTg

Thx, it will take a number of watchings to completely get what he was saying

While it depends on how the motherboard is set up, typically your GPU uses 16 PCIE lanes directly to the CPU.  Additional PCIE lanes are provided by the motherboard chipset, and are used for such things as your NVME storage.

Mike

So, is it correct to say the PCIe lanes provided by the cpu are connected and will be used for the m.2 stick?

You are restricted to 16 lanes altogether. Your GPU really only needs 8 lanes (x8). I tested x16/x16 versus x8/x8 and found a (perhaps) 1% advantage to x16/x16, while a single card sometimes gave the advantage to the x8 setup, but only by a single frame per second.

I always build looking 5 or so yrs into the future and so I build looking at maximum performance

Thx to all for ur responses... I will most likely have more questions  :salute
Title: Re: nvme vs pcie
Post by: Ramesis on August 23, 2019, 12:55:05 PM
 
[when a mobo maker talks about having 24 PCIE lanes they are actually referring to HSIO. a HSIO is the same (sort of but not really) to a pcie lane. a mobo connects everything together. so a mobo maker will use 16 for the 16x pcie slot. they'll use 4 for ram. and 4 for all your sata ports, m.2 slots,usb connectivity and ethernet. thats a rough outline and not gospel as all mobo makers can budget the HSIO lanes a CPU has however they want for a particular mobo product.
thats the reason why connecting an M.2 slot ssd can disable one or more sata ports. they are using the same HSIO lanes to the cpu
[/quote]

I have yet to find the architecture of the i9-9900k cpu… but I did find the above



Title: Re: nvme vs pcie
Post by: Chalenge on August 24, 2019, 02:30:08 AM
Look up LGA 2066 CPUs and read the manuals for the particular motherboards you are considering. Not all motherboards use SATA ports that disable the PCIe lanes.

Again, x8 vs x16 is not a performance limiter in the case of GPUs. A measure of 1 fps is within the margin of error for FPS counters.
Title: Re: nvme vs pcie
Post by: Denniss on August 24, 2019, 03:04:44 PM
with a 9900k you'll have 16 PCIe lanes for gfx directly from the CPU, 4 more are used for connection to motherboard chipset. All PCIe lanes used for M.2 NVME SSDs are provided by the chipset.
Title: Re: nvme vs pcie
Post by: Ramesis on August 24, 2019, 03:48:57 PM
Look up LGA 2066 CPUs and read the manuals for the particular motherboards you are considering. Not all motherboards use SATA ports that disable the PCIe lanes.

Again, x8 vs x16 is not a performance limiter in the case of GPUs. A measure of 1 fps is within the margin of error for FPS counters.

Thnx for the advice Chalenge but I have already selected and received the i9-9900k which
built for a lga1151 socket

with a 9900k you'll have 16 PCIe lanes for gfx directly from the CPU, 4 more are used for connection to motherboard chipset. All PCIe lanes used for M.2 NVME SSDs are provided by the chipset.

Deniss..thx as well... I'm reseaching MoBos now
Title: Re: nvme vs pcie
Post by: Ramesis on August 24, 2019, 04:55:35 PM
Ok... I have settled on the ASUS ROG maximus XI hero (wi-Fi) as the mobo
I have had luck with the Asus mobo in the past and the price was right...
In addition I want a 2 channel wi-fi for TS purposes...
Next thing I need to research is the m.2 stick, ram and ssd drives
Thx for all all ya's help and any advice will be appreciated  :salute
Title: Re: nvme vs pcie
Post by: TequilaChaser on August 24, 2019, 08:29:02 PM
Glad you found a MB that might do all the necessary work you will be wanting to get out of your computer build, Ramesis

below is something I meant to post for you the other day, and follows up on what Chalenge posted regarding a GPU running in a PCI-E X16 slot that has access to all 16 lanes, but drops to only 8 lanes ( X8) when another card or adapter is plugged into the 2nd X16 PCI-E X16 slot

Quote
PCI-E lane complications

Even this early in M.2 development, there are already M.2 drives like the Samsung XP941 that have read speeds that are twice as fast as any SATA-based SSD. However, there is a very finite number of PCI-E lanes in a system and a M.2 PCI-E drive will need to use a certain number of them. This means that instead of checking to make sure your motherboard has enough SATA ports, you instead have to check that you have enough PCI-E slots and lanes. Many motherboards have plenty of PCI-E x16 slots, but it becomes a problem when you realize that usually very few of those slots can actually run at x16 speeds.


Asus Z97-A PCI-E slots
For example, say you have a Asus Z97-A and want to install a M.2 x4 drive using a PCI-E adapter. That motherboard has two PCI-E x1 slots and three physical PCI-E x16 slots. The two PCI-E x1 slots don't have the necessary number of PCI-E lanes for a M.2 drive so they cannot be used. For the x16 slots, it turns out that the bottom PCI-E x16 slot is actually only capable of x2 speeds, so that slot will not allow for the full speed of a M.2 x4 drive. The primary x16 slot is likely needed for the GPU so it is also not available to be used. Finally, the second x16 slot is capable of x8 speeds so it will work for the M.2 x4 drive, but using that slot will actually reduce the primary slot (and thus the GPU) to x8 speeds. We've shown in the past that modern GPUs do not show any performance loss by running at x8 speeds, but it still is not ideal. And remember, this is just to add a single M.2 x4 drive and doesn't take into account other PCI-E devices you might have like sound cards or wireless cards. If you want to add a second M.2 x4 drive, you are pretty much out of luck until someone releases a M.2 to PCI-E adapter that can handle multiple drives in a single slot.

The PCI-E lane issue is less of a problem on X79 or Xeon E5 systems since the CPU (and thus the motherboard) has more PCI-E lanes available, but you still need to plan it out ahead of time to make sure you don't run into any surprises. Hopefully future Intel CPUs will add more PCI-E lanes to make this less of an issue, but for now this is the biggest limitation we see in terms of M.2 adoption
Refrenced Link for above quoted info: https://www.pugetsystems.com/labs/articles/Overview-of-M-2-SSDs-586/#PCI-Elanecomplications

Regarding picking out a M.2 Drive...
their are 5 common M.2 Drive Lengths for mounting and 2 types of M.2 sockets ( B key / M key )

ASUS has come out with the U.2 socket as well... check out the below link if you haven't already seen it or found it in your research

https://rog.asus.com/articles/hands-on/easy-guide-to-ssds-sata-msata-m-2-and-u-2/


Hope the links and info I posted above help...


now my personal opinion/view from experiences:
as for Brands/Manufacturer and models of SSD, M.2, U.2, SATAIII etc... I prefer using Crucial over other Brands, I have yet to have one fail, unlike some I have replaced like OCZ, Plextor, Intel, Kingstonand a few others, while repairing/fixing other people's computer problems....

I've slowed down quite significantly on building new PC Builds and repairing them for others, over the past year or 2... and have not kept up on this stuff like I used to, but constantly working on and fixing other people's computerskinda knocks the wind out of the Sail, and drives one towards not even having the desire to turn on one's own personal computer, heh...
anyway...

Hope this helps

TC


Title: Re: nvme vs pcie
Post by: Ramesis on August 25, 2019, 01:16:04 PM


I've slowed down quite significantly on building new PC Builds and repairing them for others, over the past year or 2... and have not kept up on this stuff like I used to, but constantly working on and fixing other people's computerskinda knocks the wind out of the Sail, and drives one towards not even having the desire to turn on one's own personal computer, heh...

Know what u mean TC before the strokes, I repaired and installed CT and MRI computers but since then
I only keep up when I do a build and I only repair computers for family members

Thx for your assist
RAM
Title: Re: nvme vs pcie
Post by: Shuffler on August 25, 2019, 01:39:37 PM
Same here. Only when I build for me. I also work on family machines.
Title: Re: nvme vs pcie
Post by: AAIK on August 26, 2019, 08:18:02 PM
Here is another video to inform yourself:

https://www.youtube.com/watch?v=omEm40cIsI0
Title: Re: nvme vs pcie
Post by: AAIK on August 31, 2019, 05:58:26 PM
Found another video, seems to be a follow up to the first one I posted:

https://www.youtube.com/watch?v=Ffxkvf4KOt0