Do these actually work and how?

[P5EUD0NYM]

Ive been looking for an extremely cheap pcie to nvme adapter and keep seeing ones that claim they can be x4 x8 or x16. They have the normal pcie x4 then extra contact pads after short gaps so that it takes up the x8 slot size, then a gap until another set of contact pads so that it is a full x16 slit aic. (Sorry if I’m not explaining it well. If you need an example just go to Amazon or Temu and search up a pcie to nvme adapter and you’ll see a couple) Ive been thinking of getting one of these over others as they seem to be significantly cheaper. But do they actually work?

[Dutch_Master]

No. Bought one which specifically mentioned a PCIe switch via Aliexpress, when I got it: no PCIe switch It was a "normal" x16 slot and as such it works.

[Timme]

45 minutes ago, P5EUD0NYM said:

Ive been looking for an extremely cheap pcie to nvme adapter and keep seeing ones that claim they can be x4 x8 or x16. They have the normal pcie x4 then extra contact pads after short gaps so that it takes up the x8 slot size, then a gap until another set of contact pads so that it is a full x16 slit aic. (Sorry if I’m not explaining it well. If you need an example just go to Amazon or Temu and search up a pcie to nvme adapter and you’ll see a couple) Ive been thinking of getting one of these over others as they seem to be significantly cheaper. But do they actually work?

They do work. In fact, can just get an X4 adapter card and stick it in X16, no problem. Don't buy "the cheapest", though - never a good idea.
You do need to check the PCIe lanes situation on your motherboard.
edit: if you're into some tech reading, here's a bit on the topic

[P5EUD0NYM]

4 minutes ago, Timme said:

They do work. In fact, can just get an X4 adapter card and stick it in X16, no problem. Don't buy "the cheapest", though - never a good idea.
You do need to check the PCIe lanes situation on your motherboard.

Ik it’s not a good idea but I am getting these cos my friend thought it would be funny if we buy a bunch of pcie to nvme and nvme to pcie adapters and see how well it works, they wouldn’t be used long term

[Timme]

1 minute ago, P5EUD0NYM said:

Ik it’s not a good idea but I am getting these cos my friend thought it would be funny if we buy a bunch of pcie to nvme and nvme to pcie adapters and see how well it works, they wouldn’t be used long term

You need 4 PCIe lanes for each NVMe drive. An x16-capable adapter can support up to 4 NVMe drives, and that'll need 16 lanes for the thing to work. Since the number of PCIe lanes available on the motherboard is limited, and the whole thing is interconnected between a few ports that share bandwidth, every board added will significantly reduce the total available bandwidth on the motherboard circuit and/or disable another port. So you won't be able to go wild with the idea.

[Needfuldoer]

3 minutes ago, Timme said:

You need 4 PCIe lanes for each NVMe drive. An x16-capable adapter can support up to 4 NVMe drives, and that'll need 16 lanes for the thing to work. Since the number of PCIe lanes available on the motherboard is limited, and the whole thing is interconnected between a few ports that share bandwidth, every board added will significantly reduce the total available bandwidth on the motherboard circuit and/or disable another port. So you won't be able to go wild with the idea.

There's a slight catch: if the card doesn't include a PCIe switch, then your motherboard needs to support PCIe bifurcation if you want to use four 4x SSDs in one 16x slot.

[Timme]

1 minute ago, Needfuldoer said:

There's a slight catch: if the card doesn't include a PCIe switch, then your motherboard needs to support PCIe bifurcation if you want to use four 4x SSDs in one 16x slot.

Well, there are many catches, and this is but a random post on a forum. The article I linked covers most of it.

[P5EUD0NYM]

3 hours ago, Timme said:

You need 4 PCIe lanes for each NVMe drive. An x16-capable adapter can support up to 4 NVMe drives, and that'll need 16 lanes for the thing to work. Since the number of PCIe lanes available on the motherboard is limited, and the whole thing is interconnected between a few ports that share bandwidth, every board added will significantly reduce the total available bandwidth on the motherboard circuit and/or disable another port. So you won't be able to go wild with the idea.

Yes I know. However you don’t need those 4 lanes per nvme Thats just what there max lane is, right?

[Timme]

1 minute ago, P5EUD0NYM said:

Yes I know. However you don’t need those 4 lanes per nvme Thats just what there max lane is, right?

No, an NVMe drive requires 4 lanes.

[PDifolco]

4 hours ago, P5EUD0NYM said:

Ive been looking for an extremely cheap pcie to nvme adapter and keep seeing ones that claim they can be x4 x8 or x16. They have the normal pcie x4 then extra contact pads after short gaps so that it takes up the x8 slot size, then a gap until another set of contact pads so that it is a full x16 slit aic. (Sorry if I’m not explaining it well. If you need an example just go to Amazon or Temu and search up a pcie to nvme adapter and you’ll see a couple) Ive been thinking of getting one of these over others as they seem to be significantly cheaper. But do they actually work?

How many NVMe do you want to put in the adapter ? What's your board ?
For only one drive you need x4 (bandwidth) and can usually use a bottom PCIe slot using mobo lanes

I use a Sabrent adapter since years for one of my drive and it works just fine, it's also plug and play and "hot swappable" as it's toolless ! Plus there's a heatsink and the NVme is way cooler than under the GPU ! 15 bucks, maybe there are cheaper models

Then if you want 2 or more drives, larger adapters are more expensive, plus you will usually need either to use the GPU x16 slot or bifurcate it to x8x8 if it's possible on your board

 

[kokosnh]

12 hours ago, Timme said:

No, an NVMe drive requires 4 lanes.

PCIe Ssd need 1 PCIe lane to function, you can even buy PCIe x1 to m.2 adapters ( you can't connect more than one Ssd without bifurcation, but you can always make it slower, by not connecting all the pcie lanes ).

So yes, you don’t need all 4 pcie lanes connected, but you can't really do anything more with that knowledge,

PCIe bifurcation in consumer board works with the 4 PCIe lanes as the minimum count.
 

give us all the links and info of what you are looking at.  
the active PCIe 3.0 x8 switch cards (PLX8747) can be bought for like 80-100 USD on aliexpress