Nvme SSD speed not as fast as advertised.

[JimSims368]

I have recently bought an Kingston NV2 1TB M.2-2280 PCIe 4.0 x4 NVMe SSD

https://www.cclonline.com/snv2s-1000g-kingston-nv2-m-2-2280-1tb-pci-express-4-0-x4-nvme-solid-state-drive-394440/

To put in the asrock b450 steel legend motherboard, this ssd is advertised up to 3500mbs, but as you can see from the screenshot it only gets up to around 2300mbs I know the slot is gen3 on the motherboard and the SSD is gen 4 not sure if that's why.

SSD speed - https://i.imgur.com/zhUZjD0_d.webp?maxwidth=640&shape=thumb&fidelity=medium

[NF-A12x25]

 

1 minute ago, JimSims368 said:

I know the slot is gen3 on the motherboard and the SSD is gen 4 not sure if that's why.

yes that’s why LMFAO, don’t expect to get full speed of a gen 4 SSD in a gen 3 slot…

[tkitch]

Gen 3 is half the speed of gen 4.  So, yeah, that's why.

[Dukesilver27-]

Quote: 

This effectively doubles the data transfer rate or bandwidth of PCIe 3.0. The faster the throughput, the better performance you’ll see from devices such as SSDs. Keep in mind that the table is just to give you an idea about different lanes and data transfer rates. Since we are talking about SSDs, NVMe SSDs use up to 4 PCIe lanes only.

[NF-A12x25]

Just now, tkitch said:

Gen 3 is half the speed of gen 4.  So, yeah, that's why.

it’s like asking “I put a 50-50 mix of water and gas in my car, why isn’t it running right? Here’s a video of it not running right”

[Crunchy Dragon]

37 minutes ago, JimSims368 said:

the slot is gen3 on the motherboard and the SSD is gen 4 not sure if that's why.

That is why. A new motherboard will solve this problem, or you can just live with the slower than rated speeds from your SSD until an upgrade is more timely, unless you absolutely need every single bit of speed.

[Pasi123]

Which slot you put it in? The slot under the CPU socket is PCIe 3.0 x4 while the bottom one is x2. Though your read speed is above what x2 could do but way below what x4 should do.

Have you tried other tests like CrystalDiskMark?

[JimSims368]

On 11/8/2022 at 6:45 AM, Pasi123 said:

Which slot you put it in? The slot under the CPU socket is PCIe 3.0 x4 while the bottom one is x2. Though your read speed is above what x2 could do but way below what x4 should do.

Have you tried other tests like CrystalDiskMark?

Its in the top slot under the CPU yeah i have tried Crystal too it was about 100mbs faster.

[JimSims368]

On 11/8/2022 at 1:14 AM, NF-A12x25 said:

it’s like asking “I put a 50-50 mix of water and gas in my car, why isn’t it running right? Here’s a video of it not running right”

 

The SSD is only rated to go up to 3,500mbs, from the research online nvme gen 3 slot speeds is  3,000 mbs to 3,500mbs, should i not at least get those speeds?

[Ralf]

On 11/8/2022 at 2:40 AM, Crunchy Dragon said:

That is why. A new motherboard will solve this problem, or you can just live with the slower than rated speeds from your SSD until an upgrade is more timely, unless you absolutely need every single bit of speed.

This is not why. Kingston NV2 can only reach Gen3 speeds, but they advertise it as Gen4 to fool people and from this thread it looks like it's working.

10 hours ago, JimSims368 said:

 

The SSD is only rated to go up to 3,500mbs, from the research online nvme gen 3 slot speeds is  3,000 mbs to 3,500mbs, should i not at least get those speeds?

Maybe they are doing the same as with NV1 where Kingston is not guaranteeing a specific set of internal components and expects to mix controllers and NAND to hit the cheapest price points?

 

https://www.techpowerup.com/forums/threads/kingston-nv2-1-tb-m-2-nvme-ssd.298942/page-2

[kokosnh]

it's the SSD that is slow, the M.2 slot with PCIe 3.0 x4 (depending on the CPU it can be PCIe 3.0 x2 ) is actually capped at around 3940MB/s  (we usually say 3500MB/s as that's the speed of the M.2 going from chipsets by the DMI 3.0 /Chipset Downlink PCIe 3.0 x4)

PCIe 3.0 is a 8 GT/s with 128b/130b encoding, so 3.938 GB/s with 4 lanes. 

There's no penalty in this model, from going with PCIe 3.0 x4 instead of PCIe 4.0 x4.  
The PCIe is fully backwards compatible up to PCIe 1.1    
 

 

Kingston 1TB NV2 (1000GB ~ 931.32GiB), M.2, NVMe 1.4, PCIe 4 x4, 2280, SS (D 80mm x S 22mm x W 2.2mm), key M, 7g. max power 4.6 W.
Controller: Phison PS5021-E21 (1 x Cortex-R5, 4-Channels, 4CE/Channel) TSMC 12nm
NAND: Toshiba 112-Layer 3D TLC (4 x 256GB)
DRAM: NO
Warranty: 3 lat limited 320 TBW

Maximum sequential transfers within the pSLC buffer in the 1000GB version according to the manufacturer:
- Read 3,500MB/s
- Write 2,100MB/s
After writing the pSLC buffer (around 88GB on a blank SSD) sequential write drops to around 600MB/s, after over 80% write performance drops to 80MB/s, sometimes jumping back up to 600MB/s.

[JimSims368]

Just a update I have been talking with kingston they said it less than what they would expect for this ssd and that i should talk to the reatiler i brought it from.

[Lllt5]

Been using nv2 1tb on tuf b450m (pcie3) m.2 x4 slot able to get seq read around 3200MB and 2600MB on write.

[Lllt5]

On 11/12/2022 at 8:48 AM, kokosnh said:

it's the SSD that is slow, the M.2 slot with PCIe 3.0 x4 (depending on the CPU it can be PCIe 3.0 x2 ) is actually capped at around 3940MB/s  (we usually say 3500MB/s as that's the speed of the M.2 going from chipsets by the DMI 3.0 /Chipset Downlink PCIe 3.0 x4)

PCIe 3.0 is a 8 GT/s with 128b/130b encoding, so 3.938 GB/s with 4 lanes. 

There's no penalty in this model, from going with PCIe 3.0 x4 instead of PCIe 4.0 x4.  
The PCIe is fully backwards compatible up to PCIe 1.1    
 

 

Kingston 1TB NV2 (1000GB ~ 931.32GiB), M.2, NVMe 1.4, PCIe 4 x4, 2280, SS (D 80mm x S 22mm x W 2.2mm), key M, 7g. max power 4.6 W.
Controller: Phison PS5021-E21 (1 x Cortex-R5, 4-Channels, 4CE/Channel) TSMC 12nm
NAND: Toshiba 112-Layer 3D TLC (4 x 256GB)
DRAM: NO
Warranty: 3 lat limited 320 TBW

Maximum sequential transfers within the pSLC buffer in the 1000GB version according to the manufacturer:
- Read 3,500MB/s
- Write 2,100MB/s
After writing the pSLC buffer (around 88GB on a blank SSD) sequential write drops to around 600MB/s, after over 80% write performance drops to 80MB/s, sometimes jumping back up to 600MB/s.

Don't know about the nand though, fabless ssd maker often change their nand flash depending on price/supply.

Currently waiting for e21t flash id to find out what nand my 1tb nv2 use.