[SOLVED] M.2 Pcie4.0 slot bandwidth with Nvme 3gen ssd

[Hardquery]

I am planning to build a new PC with Ryzen 3700x for video editing content creation and rendering finalising motherboard between b550 b450 x470 x570 . As Nvme m2 gen4 are expensive I decided to get Samsung 970 EVO plus 1 TB which is pcie 3rd gen m.2 ssd drive.

I saw benchmark of Nvme 4 gen and Nvme 3 gen but the read write speed and bandwidth it's not huge difference it may be 200mbps to 400mbps between n Nvme 4 Nvme 3 ssd drives and price difference is huge.

I have seen in motherboards specifications configuration there are many types of M.2 second slot in different motherboards

1. M.2_2 Pcie 4x4 (64gb)
2. M.2_2 Pcie 4x2 (32gb)
3. M. 2_2 Pcie 3x4 (32GB)
4. M.2_2 Pcie 3x2 (16GB)
5. M.2_2 Pcie 2x4 (20GB)
6. M.2_2 Pcie 2x2 (10GB)

Now my confusion and queries in my mind is:-

1. If I put NVME pcie 3 3rd gen SSD drive in M.2 pcie 4.0x4 slot or M.2 pcie 3x4 slot technically what will be the difference on bandwidth or speed or Radom read write speed or sequential speed will NVME ssd 3.0 will give 2000MBs speed in M2.2 4.0x4 slot.

2. As slot speed M.2 pcie 4 is said to be 64GB whereas the benchmark reflects max upto 2000 MBps or 2GBps why so why it don't give speed of 64gb/ps

3. If m2. Second slot is used it locks or disables or degrade the speed of pcie 3 or pcie 2 or pcie 4 second slot and some disables sata 5 and sata 6 port ....then what is use of second slot then will it be better to put an external adapter m.2 card.

4. As m.2 second slot is locks pcie 2 slot so I think If I use m.2 pcie adapter card in pcie 4 x16 slot and have 2 m.2 slots will it give more or same bandwidth read write speed as the slot pcie 4x4 64 GB or it will create more latency or slower speed. If single m.2 adapter card is used in pcie 4.0 x16 slot then will give x16 speed or x4 speed.

5. If I used Raid 0 or raid 1 in m.2.1 slot and m.2.2 slot of motherboard then it's necessary to have pcie 4.x4 speed in m2 slots. Secondly is Raid 0 or Raid 1 array used in all boards work SataIII 6gbps speed.


6.Which motherbord you recommend will be good for raid cloning mirroring for Nvme drives as all company x570 and Asus x470 and b450 have same m2 first and second slot speed...whereas in b550 no boards have same m.2 slots with same pcie speed


Thanks in advance for precious time and precious advice and opinions and sharing your precious knowledge

Waiting for opinion answers to clear my confusions and queries.

 

[alceryes]

...I saw benchmark of Nvme 4 gen and Nvme 3 gen but the read write speed and bandwidth it's not huge difference it may be 200mbps to 400mbps between n Nvme 4 Nvme 3 ssd drives and price difference is huge...

Can you post your source? This doesn't seem correct as NVMe is MUCH faster than SATA, M.2 is just the form factor.
Ex. click on the ATTO link in my sig. This is a first gen WD Black NVMe.

 

[USAFRet]

PCIe 4.0 is still new. Storage devices and relevant motherboards are not yet fully up to the theoretical speed.
Secondly, the actual difference is much less than the published numbers would seem to suggest.

Your questions:
#1-4 depend completely on the specific motherboard in question
#5....unless this is a paid gig where time = money, and you are moving data between two similar RAID 0 arrays...put the RAID concept out of your thought process.

 

[Hardquery]

Can you post your source? This doesn't seem correct as NVMe is MUCH faster than SATA, M.2 is just the form factor.
Ex. click on the ATTO link in my sig. This is a first gen WD Black NVMe.

alceryes buddy sorry for typo mistake in my question. I mean to say that benchmark difference between M.2 Nvme 4th gen drive and m.2 Nvme 3rd gen drive is not much it's only 100 MBps to 500 MBps .

PCIe 4.0 vs. PCIe 3.0 SSDs Benchmarked

High performance storage is in transition as the industry is beginning to adopt the PCIe 4.0 standard. In this roundup, we'll be taking a look at the...

www.techspot.com

https://www.tomshardware.com/reviews/sabrent-rocket-nvme-40-m2-ssd-review-a-high-performance-value/2


A benchmark shows that speed difference between gigabyte Nvme 4 drive and Samsung 970 pro Nvme drive is hardly 100MBps

And the The Sabrent drive pcie 4.0 is the clear winner here and is about 500MB/s faster than the competition. Surprisingly, the PCIe 3.0 Samsung 970 Pro drive is right in it with the PCIe 4.0 drives.

The roughly price of M.2 Nvme drive Samsung 970 evo pro M.2 Nvme pcie 3.0 1TB is $90 and sambient Plus Nvme M.2 pcie4.0 1tb drive is $180 just double price and speed is just 500MBps as per benchmark.

alceryes buddy thanx for your reply. My question was related to M.2 slots in motherboard that if I put Samsung 970 evo pro m.2 pcie 3.0 in .motherboard slot of m.2 pcie 4.0 will it give 2000MBps lower speed . Or I have to get pcie 4 double price drive to get just 100 to 500 mb speed hike.

 

[alceryes]

Got it.
@USAFRet's answer is spot on. You'll only see a difference in synthetic benchmarks between third and fourth gen, NVMe drives. Unless you have a very specific 'need for speed' the third gen. drives will be fast enough for a while to come.

 

[Hardquery]

@USAFRet first thanx for replying to my queries and giving precious time and opinion and advice.

Your questions:
#1-4 depend completely on the specific motherboard in questio

@USAFRet bro thanx again.

As work of M.2 drive is booting windows and Linux multi instances of OS and work I do is for content creation video editing or rendering or for data recovery or designing .

As my work is professional and R& D and windows crashes so I use multi OS or I used to Acronis disk director for imaging cloning or backup my SSD HDD for fast recovery. I to used Raid 1 for mirroring or Raid 0 for parallel writing. But I am novice new to M.2 drives.

I prefer gigabyte board due to dual bios option for faster bios recovery and update. But M.2.2 and VRM and future upgradability is also a concern for me .

I am confused with to select any of one motherboards as per M.2 slots

Gigabyte x570 Arous elite have both m.2 Pice 4(64GB)

gigabyte x470 ultra gaming have M.2 2slot with pcie 2x4 (20GB) and first m.2.1 slot with pcie pcie3x4 (32GB) and

gigabyte B550 Arous pro have first M.2 slot of pcie 4x4(64GB) and second M.2 slot with Pcie 3x4 32 GB

Secondly Asus b450 Rog strix-F II have both slot of M.2 with pcie 3 x4 (32GB)

Thirdly Asus x570 Rog strix-F have both m.2 slot of pcie 4.4 (64GB)

Asus b550 Rog strix-F have first slot of pcie4x4 (64GB) and second slot of pcie3x4 (32GB)

I had planned to get two Samsung 970 evo plus Nvme pcie 3.0 1TB drives The major first question in my mind is that is that as the speed of benchmark of M.2 Nvme drives is max upto 2000 MBp/s I.e 2GBp/s then will the speed of slot matters or is concerned as pcie 2x4 to gives 20Gbps speed.

Means for raid or cloning or imaging from first slot M.2 Nvme to second slot NVMe should I go for same speed both slot with speed or it slot speed will hardly effect the bandwidth.
Ie. Pcie4x4 first and pcie 4x4 second slot
Or pcie4x4 (64GB) first slot and second slot pcie 4x3 (32GB) 50% speed difference
Or pcie3.0x4(32GB) and second slot pcie 2.0 x4 (20GB) 38% speed difference.

As you said

PCIe 4.0 is still new. Storage devices and relevant motherboards are not yet fully up to the theoretical speed.

As if the M2 drives don't use the actual m.2 slot pcie 3x4(32GB) theortical speed even or even pcie2x4(20GB) then why to invest money on the slot which is not reached. For a hope for future may be such devices come in furure... But I think within 2021 -2022 there will be huge changes of CPU slots may be AM5 and ram slots after launch of DDR5 and we have to upagrade to see actual use of M.2 pcie 4 speed practically

 

[USAFRet]

PCIe 3.0 gives a theoretical 3500MB/s. The Samsung 970 can deliver that. Not 2000.
PCIe 4.0 can go to a theoretical 7000MB/s.

4.0 is still new, and devices have not yet been optimised to reach that full potential.
Much like DDR4 RAM when it first appeared. Initial products were no better performing than the DDR3 RAM. Only later did they actually get faster.

 

[Hardquery]

PCIe 3.0 gives a theoretical 3500MB/s. The Samsung 970 can deliver that. Not 2000.
PCIe 4.0 can go to a theoretical 7000MB/s.

4.0 is still new, and devices have not yet been optimised to reach that full potential.
Much like DDR4 RAM when it first appeared. Initial products were no better performing than the DDR3 RAM. Only later did they actually get faster.

@USAFRet thanx again a lot. OK got it.that's the actual therotocal speed difference Info I was searching for.

I got that, M I right on following do correct if I am wrong

P4x4 theoritical speed is 7000MBps
P4x2 therotical speed will be 3500MBPs ?

P3 x4 theoritical speed is 3500 MBPs
P3x2 theoritical speed will be 1750 MBps

P2x4 theoritical speed is 1680 MBPs
P2x2 theoritical speed will be 800 MBPs

Kindly correct if i m wrong somewhere if I put M.2 samsung evo pro 970 nvme gen3 drive or in p3x4 then it can go up to 3500 MBps if I put it in p2x4 will speed go down to 1750MBps or not? and if I put it in p4x4 can it reach up to 7000 MBPs or not?

Same way if I put M.2 Sambient plus nvme pcie4 gen4 drive or any new upcoming gen4 good speed drive in p4x4 slot then it may give speed up to 7000 MBps but if i pit in second slot p3x4 will it degrade spped to 3500 MBps and if I put it in p2x4 will it degrade it to 1680MBps speed.


@USAFRet soory I know I mau be troubling by asking the questions again and again but I want to clear my knowledge and doubts for selecting m2.2 selection board. Thanx in advance and will be grateful if u clear my doubt and correct my knowledge.

 

[USAFRet]

M.2 samsung evo pro 970 nvme gen3 ........ and if I put it in p4x4 can it reach up to 7000 MBPs or not?

No.
The drive AND the port have performance limits.

No matter what level port you put a Samsung 970 in, it will never benchmark more than 3500MBs.

 

[Hardquery]

No.
The drive AND the port have performance limits.

@USAFRet yes So what's therotical limit of pcie2x4 m.2.2 second slot

 

[USAFRet]

@USAFRet yes So what's therotical limit of pcie2x4 m.2.2 second slot

1/2 that of PCIe 3.0 x4.

500MB/s per channel, so 2000MB/s. But probably a bit less than that due to processing overhead.