Jump to content
Search In
  • More options...
Find results that contain...
Find results in...
Mrcrysis2000

NVMe SSD only working at 800Mbps

Recommended Posts

Posted · Original PosterOP

Hi,

 

I'm trying to understand why my new 970 Evo NVMe drive in M.2 is working at half the rated speed. The drive is rated for over 3000Mbps transfer rates. but I'm getting less than half.

 

Looking into it Samsung Magician software says its connected PCIe Gen 2 x 2. On my Gigabyte gaming 7 Z98 board with an i7 4790k.

 

I'm confused is my NVMe drive limited in a way? is the port on the board just naturally slower? Because the promo stuff says that the port can transfer at 10Gbps (Image) 

 

My board is also PCIe 3.0 supported. would it be better to get a PCI adapter for the M.2 drive?

 

Thanks in advanced!

 

m.2.PNG

Link to post
Share on other sites

pcie gen 2x2 is about 800mBit/s so those speeds seems right.

 

gbit != gByte

 

so 10 gbit is about 800 mByte/s due to overhead and ecnoding and bit vs byte

 

 

your board only has pcie 3 on the cpu lanes, and thats probably all taken by the gpu at this board. Your drive is using the chipset lanes.

 

This really won't matter anyways as your still getting the iops and thats what really matters here. Your never going to use those sequential speeds.

Link to post
Share on other sites

As above, you would need PCI-e x4 for the drive to work optimally, and since you';re limited to x2 on the chipset that's why it's sequential speeds would be greatly reduced. If you have pci-e lanes spare you could get a pci-e adaptor to go in the pci-e slot, Are you running a discrete GPU or other devices in your pci-e slots?


Please quote my post, or put @paddy-stone if you want me to respond to you.

https://www.dictionary.com/  is good for helping with spelling, if you care.

 

Spoiler
  • PCs:-
  • Main PC build  https://uk.pcpartpicker.com/list/GZWxgJ
  • ASUS x53e  - i7 2670QM / Sony BD writer x8 / Win 10, Elemetary OS, Ubuntu/ Samsung 830 SSD
  • Lenovo G50 - 8Gb RAM - Samsung 860 Evo 250GB SSD - DVD writer
  • Displays:-
  • Philips 55 OLED 754 model
  • Panasonic 55" 4k TV
  • LG 29" Ultrawide
  • Philips 24" 1080p monitor as backup
  • Storage/NAS/Servers:-
  • ESXI/test build  https://uk.pcpartpicker.com/list/4wyR9G
  • Main Server https://uk.pcpartpicker.com/list/3Qftyk
  • Backup server - HP Proliant Gen 8 4 bay NAS running FreeNAS ZFS striped 3x3TiB WD reds
  • HP ProLiant G6 Server SE316M1 Twin Hex Core Intel Xeon E5645 2.40GHz 48GB RAM
  • Gaming/Tablets etc:-
  • Xbox One S 500GB + 2TB HDD
  • PS4
  • Nvidia Shield TV
  • Xiaomi/Pocafone F1 128GB 6GB RAM
  • Xiaomi Redmi Note 4
  • Lenovo k3 note
  • Windows tablet
  • Unused Hardware currently :-
  • i7 6700K  b250 mobo - Thermaltake Core V21-  EVGA Supernova G2 650W Gold PSU
  • AMD phenom II 1055t / 8GB RAM / DVD writer
  • Zotac GTX 1060 6GB Amp! edition x2
  • Zotac GTX 1050 mini
  • Nvidia Shield K1 tablet

 

 

Link to post
Share on other sites

PCIe 2.0 x2 has a 10 Gbit/s raw transfer rate. But it uses 8b/10b encoding, so you lose 20% and only 8 Gbit/s is actually usable. That is the same as 1 GB/s. With real-world inefficiencies, you're only going to be able to get 800-900 MB/s out of that. So yeah, you're being limited by the slot.

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×