# PSA: PCI-E 4.0 to M.2 nVME adapters (like the Gigabyte GC-4XM2G4) are rebadged PCI-E 3.0 cards, don't waste your money



## terroralpha (Feb 19, 2020)

hello,

if you are absolutely insane like me, you may have considered a triple or quad PCI-E 4.0 nVME M.2 RAID 0 set up via a PCI-E to M.2 adapter such as the asus hyper m.2 card or gigabyte 4xm2g4 card.

i got my paws on a gigabyte PCI-E "4.0" quad M.2 adapter (costs $130+). also picked up an asus Hyper M.2 on amazon while it was on sale for $35 (currently listed at $55), because why not. decided to bench my Corsair MP600 SSDs on the asus 3.0 card and gigabyte 4.0 card. results are pretty much identical. getting just a little over 5000MB/s sequential writes, and 4300MB/s sequential reads. PCBs look mostly the same. there is some power circuitry by no controllers of any kind. the cards just pass the PCI-E lanes in groups of 4x to each M.2 slot.

i have some pictures and screen grabs that i can post if you guys would like, but long story short don't both with the far more expensive 4.0 cards unless you really have to burn your cash. the gigabyte card is already packed up to go back to amazon.


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## thesmokingman (Feb 19, 2020)

3.94 GB/s  is max of gen3 x4 throughput. Not even worth explaining the relevance to op.


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## terroralpha (Feb 19, 2020)

quick point summary:
-SSD is 4.0
-motherboard/CPU is 4.0
-PCI-E to M.2 adapter doesn't make a difference. all it's doing is splitting the 16 lanes of the PCI-E slot into 4 and channeling them to each M.2 slot. "PCI-E 3.0" and "PCI-E 4.0" is just marketing BS for the *PCI-E to M.2 adapter*


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## terroralpha (Feb 19, 2020)

thesmokingman said:


> 3.94 GB/s  is max of gen3 x4 throughput. Not even worth explaining the relevance to op.



again,
-SSD is 4.0
-motherboard/CPU is 4.0
-PCI-E to M.2 adapter doesn't make a difference. all it's doing is splitting the 16 lanes of the PCI-E slot into 4 and channeling them to each M.2 slot. "PCI-E 3.0" and "PCI-E 4.0" is just marketing BS for the *PCI-E to M.2 adapter*



cucker tarlson said:


> no I didn't
> @thesmokingman apparently does



ah, i see what happened.


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## cucker tarlson (Feb 19, 2020)

terroralpha said:


> ah, i see what happened.


I didn't look at your specs and thought you bought a gen4 adapter to get gen4 speed on a 3.0 mobo


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## Valantar (Feb 19, 2020)

terroralpha said:


> hello,
> 
> if you are absolutely insane like me, you may have considered a triple or quad PCI-E 4.0 nVME M.2 RAID 0 set up via a PCI-E to M.2 adapter such as the asus hyper m.2 card or gigabyte 4xm2g4 card.
> 
> ...


Well, as long as the trace layout is good and the PCB is well made there's no reason for them to be different. I guess they could stick some redrivers on the 4.0 one, but they might just be an unnecessary addition to the BOM. Of course then there shouldn't be any price difference either. Have you checked the actual interface speed of your drives when using the 3.0 adapter? They might still be running at 4.0 speeds. Also, which motherboard slot is the adapter installed in? Trace length matters a lot for PCIe 4.0, so closer to the CPU might perform better.


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## theonek (Feb 19, 2020)

these cards are cheap because they are a simple riser card for 4 nvme drives, all depends on mobo and it's bios to support pci-e buriffication to support 4 drives in one pci-e x16 slot, that's all, there is no extra pci-e controller on board...


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## londiste (Feb 19, 2020)

Since, as you said, there is no active circuitry on the board the board itself does not do much.
The difference is that if the board should malfunction with PCIe 4.0 somehow (dropping to 3.0, random issues, slow speeds) you can beat the seller/manufacturer for it


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## bonehead123 (Feb 19, 2020)

Been there, done that.....

It seems that you currently have 2 options in this scenario:

A)  Get a uppoer-tier mobo that specifically supports splitting the lanes, which from my understanding, will only work in a 16x slot (mostly Z390-series or better, maybe a few others)...

B)  Fork out *ALOT* moar $$ for a card that has a chip onboard to handle the splitting...

Otherwise, you are SOL & just wasting your money on the budget cards, and you WILL be severely disappointed like I was...

If anyone knows of another proven solution, please elaborate...


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## bug (Feb 19, 2020)

terroralpha said:


> quick point summary:
> -SSD is 4.0
> -motherboard/CPU is 4.0
> -*PCI-E to M.2 adapter doesn't make a difference*. all it's doing is splitting the 16 lanes of the PCI-E slot into 4 and channeling them to each M.2 slot. "PCI-E 3.0" and "PCI-E 4.0" is just marketing BS for the *PCI-E to M.2 adapter*


What do you mean it doesn't make a difference? Where would you stick 3 NVMe drives without it?


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## kapone32 (Feb 19, 2020)

Regardless of what people are saying the OP should be seeing much higher sequential speeds using a PCI E4.0 Riser card vs a PCI 3.0 riser card. On TR4 all of the PCI-E lanes are connected to the CPU. The speeds the OP reported seem low to me if he is using 2 NVME drives that are 4.0 he should be in the 8000-9000 sequential range. I am on X399 and get over 7000 with 4 Intel 660Ps and over 6000 with 2 Adata Sx8200s Pro. Both of those are in Asus PCI 3.0 M2 riser cards.


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## bug (Feb 19, 2020)

kapone32 said:


> Regardless of what people are saying the OP should be seeing much higher sequential speeds using a PCI E4.0 Riser card vs a PCI 3.0 riser card. On TR4 all of the PCI-E lanes are connected to the CPU. The speeds the OP reported seem low to me if he is using 2 NVME drives that are 4.0 he should be in the 8000-9000 sequential range. I am on X399 and get over 7000 with 4 Intel 660Ps and over 6000 with 2 Adata Sx8200s Pro. Both of those are in Asus PCI 3.0 M2 riser cards.


Yes, but his problem can be caused by a number of things, you can't just single out the adapters.


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## cucker tarlson (Feb 19, 2020)

Why do high end x470/370 boards get no pci-e gen4 then?


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## bug (Feb 19, 2020)

cucker tarlson said:


> Why do high end x470/370 boards get no pci-e gen4 then? Dick move.


Oh, come on. Even this hadn't been discussed to death already, it's still off-topic.


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## cucker tarlson (Feb 19, 2020)

bug said:


> Oh, come on. Even this hadn't been discussed to death already, it's still off-topic.


not off topic if it follows.
a basic m.2 card is good enough to pass 4.0 signal,but a $250 board isn't.
it has been discussed and the excuse has always been "circuitry not good enough"


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## kapone32 (Feb 19, 2020)

bug said:


> Yes, but his problem can be caused by a number of things, you can't just single out the adapters.



Indeed it could be that. I would suggest that the OP tries the same thing with his M2s in the M2 slots on the board and compare the differences vs the Riser cards.


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## bug (Feb 19, 2020)

cucker tarlson said:


> not off topic if it follows.
> a basic m.2 card is good enough to pass 4.0 signal,but a $250 board isn't.
> it has been discussed and the excuse has always been "circuitry not good enough"


We can't settle this here. Read a bit about signal integrity, that'll help you understand the official explanations better. And please refrain from further posts on the subject until you do.


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## cucker tarlson (Feb 19, 2020)

bug said:


> We can't settle this here. Read a bit about signal integrity, that'll help you understand the official explanations better. And please refrain from further posts on the subject until you do.


excuses,excuses.
mb manufacturers wanted to,amd denied their good will.


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## king of swag187 (Feb 19, 2020)

There are some adapters that actually multiplex lanes, however adapters that are just bare PCBs do nothing.


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## Valantar (Feb 19, 2020)

cucker tarlson said:


> excuses,excuses.
> mb manufacturers wanted to,amd denied their good will.


Manufacturers wanted to*

*without any form of testing or verification (as this costs R&D money, which they don't want to spend on already existing products), which would inevitably lead to bugs and compatibility issues, which would then mostly lead to people complaining that AMD is falsely advertising PCIe 4.0 capabilities as that's how PCMR logic works. While I would have liked to see this enabled as a beta, caveat-laden, try-at-your-own-risk, separate BIOS install, AMD still did the right thing disabling it in the official AGESAs. It's not like you're losing anything anyhow, the sequential speeds of PCIe 4.0 drives pretty much only happen in benchmarks for the average user. Other than that you need some _very_ specific workloads to hit >PCIe 3.0 speeds in the real world.


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## Ahhzz (Feb 19, 2020)

Original Topic, gentlefolk. Find it, stay on it, please.


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## terroralpha (Feb 20, 2020)

kapone32 said:


> Indeed it could be that. I would suggest that the OP tries the same thing with his M2s in the M2 slots on the board and compare the differences vs the Riser cards.


i ran the crystaldisk benches on my TRX40 motherboard's own M.2 slot (which is where i used this SSD for a few months now, see my signature for cpu-z validation), the asus "3.0" adapter and the gigabyte "4.0" adapter. results basically identical. 5020-5060 read, ~4300 writes.

you don't have to take my word for it. if anyone wants to buy the pci 4.0 nvme adapters for $130-$150, they can. i don't benefit from it either way. this was just a curiosity experiment that worked out better than i thought and if someone wants to save enough cash to buy a whole extra SSD, they can



king of swag187 said:


> There are some adapters that actually multiplex lanes, however adapters that are just bare PCBs do nothing.



not sure how to understand that. the adapter converts the motherboard's power from 12V to whatever it is that M.2 SSDs use (3.3V?). but i'm looking at the _data_ PCB traces now, and the ones going from the _data_ portion of the PCI-E slot are going straight to the M.2 slots with no ICs in between.


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## theonek (Feb 20, 2020)

as i saidm just a riser card for 4 nvme's. Speed transfer only depends on ssd drive you use and motherboard....


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## TheoneandonlyMrK (Feb 20, 2020)

theonek said:


> as i saidm just a riser card for 4 nvme's. Speed transfer only depends on ssd drive you use and motherboard....


His Op said the same, don't buy gigabytes version, it's no better but much dearer for nothing.
The Op was advisory , it's others derailer attempts that make it seam otherwise.


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## aQi (Feb 20, 2020)

Well i dont know about this, i had my pause after getting 6000mb reads on Dell Samsung PM1725a PCI express x8 3.2tb card.


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## TheoneandonlyMrK (Feb 20, 2020)

Aqeel Shahzad said:


> Well i dont know about this, i had my pause after getting 6000mb reads on Dell Samsung PM1725a PCI express x8 3.2tb card.


You can get read speeds like that from a samy Evo with magic installed and boost on its also got x8 pciex connection.
Either way the Op is telling you how it IS not how it might be ,I have a Asus hyerx2 nvme adapter, it's just a simple lame pass through, what's there to confuse?.


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## Papahyooie (Feb 20, 2020)

OP is saying that this riser card is no different than if you were able to wedge 4 drives directly into the PCE-E slot. So to put branding on them that claims PCI-E 3.0 or 4.0 is just marketing, so there's no point in spending more money on a 4.0 one, except _perhaps_ that you can hold the manufacturer liable for not holding up to their speed claims _if the signal quality doesn't hold up. _

Don't make it more complicated than that. That's the /thread.


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## king of swag187 (Feb 20, 2020)

terroralpha said:


> i ran the crystaldisk benches on my TRX40 motherboard's own M.2 slot (which is where i used this SSD for a few months now, see my signature for cpu-z validation), the asus "3.0" adapter and the gigabyte "4.0" adapter. results basically identical. 5020-5060 read, ~4300 writes.
> 
> you don't have to take my word for it. if anyone wants to buy the pci 4.0 nvme adapters for $130-$150, they can. i don't benefit from it either way. this was just a curiosity experiment that worked out better than i thought and if someone wants to save enough cash to buy a whole extra SSD, they can
> 
> ...


It doesn't need to "convert" anything, PCIE encompasses 3.3V power as well.


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## TheoneandonlyMrK (Feb 20, 2020)

king of swag187 said:


> It doesn't need to "convert" anything, PCIE encompasses 3.3V power as well.


Probably does, the 3.3v line is probably strained by four nvme drive's, I don't know what current it will handle but probably not four drive's worth.
Nothing on a GPU besides the fan NEEds 12v but a GPU is not powered by The 3.3v line either.


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## londiste (Feb 20, 2020)

PCIe spec for 3.3 V is 3 A. Anything beyond 9.9 W will require additional power (most likely conversion from 12 V).


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## aQi (Feb 22, 2020)

theoneandonlymrk said:


> You can get read speeds like that from a samy Evo with magic installed and boost on its also got x8 pciex connection.
> Either way the Op is telling you how it IS not how it might be ,I have a Asus hyerx2 nvme adapter, it's just a simple lame pass through, what's there to confuse?.



wait what ? With magic i got just around 4gb/s
Which drive are you talking about specifically.
I guess thats off topic..


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## TheoneandonlyMrK (Feb 22, 2020)

Aqeel Shahzad said:


> wait what ? With magic i got just around 4gb/s
> Which drive are you talking about specifically.
> I guess thats off topic..


I thought it was any Evo, it's just a ram drive effectively used as a cache via magic.

Finally have the rest of my possible brain fart scenario on the way, if the Op and my assumptions in agreement with him are right then I'm in for Fun trying to get four 1Tb drive's working in the X8 (16 Physical) I have for it in my main rig, least I'll Know.


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## TheoneandonlyMrK (Mar 1, 2020)

*So after thoroughly testing and experiencing the hyperx16 Asus card on a x470 platform *I can safely say it is just a pass through ,on my board I can only get two working in it If no nvme is fitted to m.2 2 And I have one in a cheap X1 adapter in the bottom x4 pciex slot so one nvme for boot and three raided.
You really need thread ripper to use it fully Even vroc limits it via dma bus on mainstream intel to one drive's bandwidth essentially.
I have not found anything that recognises and raid to bench it but games load snappy.


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## TheLostSwede (Mar 1, 2020)

Papahyooie said:


> OP is saying that this riser card is no different than if you were able to wedge 4 drives directly into the PCE-E slot. So to put branding on them that claims PCI-E 3.0 or 4.0 is just marketing, so there's no point in spending more money on a 4.0 one, except _perhaps_ that you can hold the manufacturer liable for not holding up to their speed claims _if the signal quality doesn't hold up. _
> 
> Don't make it more complicated than that. That's the /thread.


This is factually incorrect.
The reason for PCIe 3.0 and PCIe 4.0 versions of these things are because they use different PCIe redrivers. A PCIe 3.0 redriver can't operate at PCIe 4.0 speeds, so you'll never get PCIe 4.0 speeds with a PCIe 3.0 card.


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## TheoneandonlyMrK (Mar 1, 2020)

TheLostSwede said:


> This is factually incorrect.
> The reason for PCIe 3.0 and PCIe 4.0 versions of these things are because they use different PCIe redrivers. A PCIe 3.0 redriver can't operate at PCIe 4.0 speeds, so you'll never get PCIe 4.0 speeds with a PCIe 3.0 card.


I'm not sure even a pciex 4 one would absolutely need a re driver but three definitely doesn't.
They are pin compatible and backwards compatible , I wouldn't bet either way but I haven't the pciex4 to test that, hmmn itch.


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## TheLostSwede (Mar 1, 2020)

theoneandonlymrk said:


> I'm not sure even a pciex 4 one would absolutely need a re driver but three definitely doesn't.
> They are pin compatible and backwards compatible , I wouldn't bet either way but I haven't the pciex4 to test that, hmmn itch.


All the cards that takes multiple M.2 SSDs that I've seen, all use redrivers. The signal integrity wouldn't be maintained without them.


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## TheoneandonlyMrK (Mar 2, 2020)

TheLostSwede said:


> All the cards that takes multiple M.2 SSDs that I've seen, all use redrivers. The signal integrity wouldn't be maintained without them.


I didn't look that well then I thought it all vrms and such.


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## TheLostSwede (Mar 2, 2020)

theoneandonlymrk said:


> I didn't look that well then I thought it all vrms and such.


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## Papahyooie (Mar 2, 2020)

TheLostSwede said:


> This is factually incorrect.
> The reason for PCIe 3.0 and PCIe 4.0 versions of these things are because they use different PCIe redrivers. A PCIe 3.0 redriver can't operate at PCIe 4.0 speeds, so you'll never get PCIe 4.0 speeds with a PCIe 3.0 card.


Take that up with the OP. I didn't make the claim. Simply clarifying what he was saying, as the thread was going all sorts of irrelevant.


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