WD SN850 SSD underperforming

[Antonio Nunes]

Hey everyone,

First of all I apologize if I'm writing in the wrong section I am very new to the forum. Also please excuse my English as it is not my first language

 

So I bought a WD SN850 SSD, since I happened to catch it at a reasonable price. The thing is advertised as being able to push 7000Mb/s read and 5300Mb/s write.

That being said, I've ran Crystal Disk Mark a couple of times on it, and it is only able to reach 3500/2500.

I have one other SSD from WD that is performing exactly like expected.

 

One thing that I have to note is that the WD SN850 is Gen 4.0, but my motherboard (Asus Maximus XI) has Gen3.0 x4 Nvme slots. I was pretty silly to buy the ssd before reading the manual, but from what I understand Gen3 should be able to push 15Gb/s, so why is my SSD pushing half of what's advertised? Could it be faulty? Is it really because of Gen4.0 vs Gen3.0 slot? Or am I missing something? (probably the most likely possibility)

 

Just to tick some boxes:

BIOS is updated

Windows is updated

SSD firmware is updated

WD dashboard says drive health is normal (100%)

WD S.M.A.R.T extended diagnostic found no problems with the drive

 

Anyways, thanks in advance for any help, be sure to ask me for more specs if you think the problem might be coming from somewhere else.

And again sorry for my likely ineptitude.

[JamesTheFolf]

5 minutes ago, Antonio Nunes said:

Hey everyone,

First of all I apologize if I'm writing in the wrong section I am very new to the forum. Also please excuse my English as it is not my first language

 

So I bought a WD SN850 SSD, since I happened to catch it at a reasonable price. The thing is advertised as being able to push 7000Mb/s read and 5300Mb/s write.

That being said, I've ran Crystal Disk Mark a couple of times on it, and it is only able to reach 3500/2500.

I have one other SSD from WD that is performing exactly like expected.

 

One thing that I have to note is that the WD SN850 is Gen 4.0, but my motherboard (Asus Maximus XI) has Gen3.0 x4 Nvme slots. I was pretty silly to buy the ssd before reading the manual, but from what I understand Gen3 should be able to push 15Gb/s, so why is my SSD pushing half of what's advertised? Could it be faulty? Is it really because of Gen4.0 vs Gen3.0 slot? Or am I missing something? (probably the most likely possibility)

 

Just to tick some boxes:

BIOS is updated

Windows is updated

SSD firmware is updated

WD dashboard says drive health is normal (100%)

WD S.M.A.R.T extended diagnostic found no problems with the drive

 

Anyways, thanks in advance for any help, be sure to ask me for more specs if you think the problem might be coming from somewhere else.

And again sorry for my likely ineptitude.

It's possible they changed out some of the components and it could be affecting performance. This is what Linus and Luke are talking about in this video down below.

 

[AnirbanG007]

6 minutes ago, Antonio Nunes said:

Hey everyone,

First of all I apologize if I'm writing in the wrong section I am very new to the forum. Also please excuse my English as it is not my first language

 

So I bought a WD SN850 SSD, since I happened to catch it at a reasonable price. The thing is advertised as being able to push 7000Mb/s read and 5300Mb/s write.

That being said, I've ran Crystal Disk Mark a couple of times on it, and it is only able to reach 3500/2500.

I have one other SSD from WD that is performing exactly like expected.

 

One thing that I have to note is that the WD SN850 is Gen 4.0, but my motherboard (Asus Maximus XI) has Gen3.0 x4 Nvme slots. I was pretty silly to buy the ssd before reading the manual, but from what I understand Gen3 should be able to push 15Gb/s, so why is my SSD pushing half of what's advertised? Could it be faulty? Is it really because of Gen4.0 vs Gen3.0 slot? Or am I missing something? (probably the most likely possibility)

 

Just to tick some boxes:

BIOS is updated

Windows is updated

SSD firmware is updated

WD dashboard says drive health is normal (100%)

WD S.M.A.R.T extended diagnostic found no problems with the drive

 

Anyways, thanks in advance for any help, be sure to ask me for more specs if you think the problem might be coming from somewhere else.

And again sorry for my likely ineptitude.

I don't know about advertised speeds, I found this article that has very similar numbers to what you got. https://www.techquila.co.in/wd-black-sn850-ssd-review/ Idk if the advertised numbers include some sort of caching using the RAM like HMB, it could tho.

 

While I may not be able to help you out on this topic much, I just wanna say your English is very decent.  

[JamesTheFolf]

It's also possible the under performance could be because of the hardware you have isn't fast enough to support the speeds.

 

I just read this article, and it seems like the highest performance of Gen3 Nvme drives is 3500 Mb/s

TechSpot

[JamesTheFolf]

It also seems that the last gen version of this same SSD gets a little less than the performance of that one.

[boggy77]

28 minutes ago, Antonio Nunes said:

Is it really because of Gen4.0 vs Gen3.0 slot?

yes, it's literally that. you are using a 7GBps ssd in a 3.9GBps slot

[Antonio Nunes]

21 minutes ago, AnirbanG007 said:

I don't know about advertised speeds, I found this article that has very similar numbers to what you got. https://www.techquila.co.in/wd-black-sn850-ssd-review/ Idk if the advertised numbers include some sort of caching using the RAM like HMB, it could tho.

 

While I may not be able to help you out on this topic much, I just wanna say your English is very decent.  

Thanks, this article does seem to have the same write/reads as I'm getting. I did base my expectations on the following video (check the 21:45 minute mark). Much higher and according to the advertised. But it seems the problem might come from the reason below .

 

16 minutes ago, jrhaberland said:

It's also possible the under performance could be because of the hardware you have isn't fast enough to support the speeds.

 

I just read this article, and it seems like the highest performance of Gen3 Nvme drives is 3500 Mb/s

TechSpot

 

14 minutes ago, jrhaberland said:

It also seems that the last gen version of this same SSD gets a little less than the performance of that one.

 

Thanks for the Linus vid. Well, it might just be that: In fact PCIE 3.0 x4 seems to max out at 4Gb/s, was reading x16 speeds (16Gb/s), silly me!

Kind of sad I didn't properly read the stuff I was supposed to, was expecting the mobo to be Gen4.0 capable since it isn't that old. But oh well, perhaps I'll keep it, its more recent and does outperform a little the SN750, even in this situation. Maybe I'll reap the full benefits when I upgrade the motherboard in the future.

 

Just now, boggy77 said:

yes, it's literally that. you are using a 7GBps ssd in a 3.9GBps slot

You are absolutely right, should've paid more attention to the tables. Many thanks!

Edited January 29, 2021 by Antonio Nunes

[JamesTheFolf]

1 minute ago, Antonio Nunes said:

Thanks, this article does seem to have the same write/reads as I'm getting. I did base my expectations on the following video (check the 21:45 minute mark). Much higher and according to the advertised. But it seems the problem might come from the reason below .

 

 

 

Thanks for the Linus vid. Well, it might just be that: In fact PCIE 3.0 x4 seems to max out at 4Gb/s, was reading x16 speeds (16Gb/s), silly me!

Kind of sad I didn't properly read the stuff I was supposed to, was expecting the mobo to be Gen4.0 capable since it isn't that old. But oh well, perhaps I'll keep it, its more recent and does outperform a little the SN750, even in this situation. Maybe I'll reap the full benefits when I upgrade the motherboard in the future.

 

 

Yeah you're getting a little extra performance now, and then when you upgrade you will have much more performance.