Best M.2 NVMe PCIe adapter

Linkz

Limp Gawd
Joined
Jan 30, 2008
Messages
355
Hey all,

I'm looking for a recommendation for a M.2 NVMe PCIe adapter, I have 2 Samsung 870 Evos 1TB and I want to add a third. I have a ASUS ROG Maximus XI Hero (Wi-Fi) and I'm currently using the 2 M2 slots on the board, so I figured PCIe could be the best to add another one (maybe 2). So anything I need to know about these?

I saw this one StarTech. I have a StarTech KVM at work so that's all I know about the brand.
 

Jack Of Owls

Weaksauce
Joined
Jan 3, 2021
Messages
89
Hey all,

I'm looking for a recommendation for a M.2 NVMe PCIe adapter, I have 2 Samsung 870 Evos 1TB and I want to add a third. I have a ASUS ROG Maximus XI Hero (Wi-Fi) and I'm currently using the 2 M2 slots on the board, so I figured PCIe could be the best to add another one (maybe 2). So anything I need to know about these?

I saw this one StarTech. I have a StarTech KVM at work so that's all I know about the brand.

I used an old Lycom DT-120 M.2 PCIe to PCIe 3.0 x4 Adapter for my EVO M.2 and learned the hard way about PCIe slots that share bandwidth with other slots/intefaces on my old Z87 motherboard. So just be careful and check your motherboard manual about which slots share bandwidth or actually end up disabling other slots and you should be good to go.
 

ZodaEX

2[H]4U
Joined
Sep 17, 2004
Messages
3,820
I used an old Lycom DT-120 M.2 PCIe to PCIe 3.0 x4 Adapter for my EVO M.2 and learned the hard way about PCIe slots that share bandwidth with other slots/intefaces on my old Z87 motherboard. So just be careful and check your motherboard manual about which slots share bandwidth or actually end up disabling other slots and you should be good to go.
Wasn't the whole idea of lanes so that pci-e slots don't have to share bandwidth with one another?
 

kirbyrj

Fully [H]
Joined
Feb 1, 2005
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28,443
I am pretty sure the 870 EVO's are 2.5" SATA drives and don't need a m.2 to PCIe adapter. Maybe you meant you have 970 EVO's.
I bought this cheap one but haven't had a chance to test it out,
https://www.amazon.com/gp/product/B07JJTVGZM/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

Samsung did have several SATA m.2 drives previously, but I can't find whether or not the 870 series made it to m.2 or not. If I can't find it easily, it probably didn't. Also, the OP should realize there's a difference between SATA (AHCI) and NVMe drives when you're talking about adapters. You have to read the fine print. Some will work with both, and others will only work with one or the other.

I used an old Lycom DT-120 M.2 PCIe to PCIe 3.0 x4 Adapter for my EVO M.2 and learned the hard way about PCIe slots that share bandwidth with other slots/intefaces on my old Z87 motherboard. So just be careful and check your motherboard manual about which slots share bandwidth or actually end up disabling other slots and you should be good to go.

There is definitely no rhyme or reason to how the bandwidth gets divided up. Definitely pays to consult the manual.

Wasn't the whole idea of lanes so that pci-e slots don't have to share bandwidth with one another?

You have to factor in where the lanes come from. The CPU has so many (usually 1st PCIe x16 slot and NVMe slot) and then after that, it's all up to the chipset as to how and where it pulls the extra lanes from.
 

Jack Of Owls

Weaksauce
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Wasn't the whole idea of lanes so that pci-e slots don't have to share bandwidth with one another?

I don't know but I was pretty damn annoyed that once I installed the Lycom adapter into one of my PCIe shots, it cut the bandwidth of my GTX 1070 video card from 16x speed to 8X speed even if I noticed no difference in real world applications (ie games) and only benchmarks could determine it was 8X. But it's the thought that wound me up lol You know how it is ;)
 

pitingres

Limp Gawd
Joined
Jul 25, 2018
Messages
174
I'm looking for a recommendation for a M.2 NVMe PCIe adapter, I have 2 Samsung 870 Evos 1TB and I want to add a third. I have a ASUS ROG Maximus XI Hero (Wi-Fi) and I'm currently using the 2 M2 slots on the board, so I figured PCIe could be the best to add another one (maybe 2). So anything I need to know about these?

I saw this one StarTech. I have a StarTech KVM at work so that's all I know about the brand.

PCIe to m.2 adapters for M key are essentially the equivalent of adapter cables. There isn't (or shouldn't be) any active circuitry other than whatever minimal stuff might be needed for the PCIe slot. The StarTech unit looks fine; I've used a Syba adapter and another no-name adapter undoubtedly out of someone's basement in Shanghai or Hong Kong; they both worked just fine. Of course, as suggested above, you'll need to check your motherboard manual / specs to see what impact using a PCIe slot will have, if any.

You'll only be able to run one NVMe SSD per PCIe slot, of course, unless you get an active card with a PCIe switch on it. That will cost a LOT more.

(and yes, the Samsung 970 EVO, EVO Plus, and Pro are all NVMe units.)
 

Linkz

Limp Gawd
Joined
Jan 30, 2008
Messages
355
I am pretty sure the 870 EVO's are 2.5" SATA drives and don't need a m.2 to PCIe adapter. Maybe you meant you have 970 EVO's.
I bought this cheap one but haven't had a chance to test it out,
https://www.amazon.com/gp/product/B07JJTVGZM/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1
Yeah sorry I meant the 970 Evo. I'll take a look at that cheap one you linked.

I used an old Lycom DT-120 M.2 PCIe to PCIe 3.0 x4 Adapter for my EVO M.2 and learned the hard way about PCIe slots that share bandwidth with other slots/intefaces on my old Z87 motherboard. So just be careful and check your motherboard manual about which slots share bandwidth or actually end up disabling other slots and you should be good to go.
I'll take a peak at the manual and see what it says, I know if I used both on board M.2 slots it will disable some sata ports but that's not an issue and the only think I have in a PCI slot current is my GPU.
 

UhClem

Limp Gawd
Joined
Jun 8, 2011
Messages
197
I looked at the specs for your mobo and ...
By using the 2 M.2 omboard connectors, yyour current two 970s are sharing PCIe bandwidth, since they are both using the z390 chipset, which relies on a 4-lane connection to the CPU. [The chipset effectively acts as a PCIe switch to share/mediate all traffic between itself (i.e., ALL of the devices connected to/through it) and the CPU.] You can demonstrate this currently by running a standard benchmark (e.g., CrystalDisk) on each of your 970s, and then run both benchmarks concurrently. See how ~3000 MB/s read became 2x~1500 read?

Now, for this 3rd M.2 in a PCIe adapter: You have 3 PCIe x16 (mechanical) slots, one of which now has your GPU. If you put the 3rd M.2 in x16 #2, it will cause your 16 PCIe lanes in the CPU (all of which are currently servicing your GPU) to be split with x8 going to the GPU and x8 going to the newly-populated x16 #2 (similar to what an earlier poster griped about); and this 3rd M.2 will have a dedicated/full-time x4 lanes of bandwidth. If, instead, you put the 3rd M.2 in x16 #3 (which really only has x4 connectivity, and is on the chipset), then all 3 M.2s will be sharing the 4 lanes CPU<==>Chipset (along with everything else on the chipset (SATAs, USBs, LAN, etc.).
 
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Linkz

Limp Gawd
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I looked at the specs for your mobo and ...
By using the 2 M.2 omboard connectors, yyour current two 970s are sharing PCIe bandwidth, since they are both using the z390 chipset, which relies on a 4-lane connection to the CPU. [The chipset effectively acts as a PCIe switch to share/mediate all traffic between itself (i.e., ALL of the devices connected to/through it) and the CPU.] You can demonstrate this currently by running a standard benchmark (e.g., CrystalDisk) on each of your 970s, and then run both benchmarks concurrently. See how ~3000 MB/s read became 2x~1500 read?

Now, for this 3rd M.2 in a PCIe adapter: You have 3 PCIe x16 (mechanical) slots, one of which now has your GPU. If you put the 3rd M.2 in x16 #2, it will cause your 16 PCIe lanes in the CPU (all of which are currently servicing your GPU) to be split with x8 going to the GPU and x8 going to the newly-populated x16 #2 (similar to what an earlier poster griped about); and this 3rd M.2 will have a dedicated/full-time x4 lanes of bandwidth. If, instead, you put the 3rd M.2 in x16 #3 (which really only has x4 connectivity, and is on the chipset), then all 3 M.2s will be sharing the 4 lanes CPU<==>Chipset (along with everything else on the chipset (SATAs, USBs, LAN, etc.).
I didn't know any of this, thanks for the detailed reply! So from what I understood, using the #2 x16 I would be slowing down/interfering with my GPU, which is currently in the top most x16 PCI slot. I need to either use the #3 x16 slot or use any of the x1 slots?
 

Nasgul

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TheSlySyl

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pitingres

Limp Gawd
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I didn't know any of this, thanks for the detailed reply! So from what I understood, using the #2 x16 I would be slowing down/interfering with my GPU, which is currently in the top most x16 PCI slot. I need to either use the #3 x16 slot or use any of the x1 slots?

Using the #2 slot would drop your theoretical GPU bandwidth in half, but that's probably the right answer for most users. Running a GPU at PCIe 3.0 x8 has minimal effect on performance for gaming, as in under 1%. Gamersnexus has a piece on this and I imagine others have tested it as well.

So your best bet overall, for that particular motherboard, is to use the second x16 slot so that the SSD isn't competing for chipset bandwidth.
 

TheSlySyl

[H]ard|Gawd
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If you use a Gen4 NVME drive, do you get Gen4 speeds with this adapter?
I would expect no.


I don't know but I was pretty damn annoyed that once I installed the Lycom adapter into one of my PCIe shots, it cut the bandwidth of my GTX 1070 video card from 16x speed to 8X speed even if I noticed no difference in real world applications (ie games) and only benchmarks could determine it was 8X. But it's the thought that wound me up lol You know how it is ;)
Using the #2 slot would drop your theoretical GPU bandwidth in half, but that's probably the right answer for most users. Running a GPU at PCIe 3.0 x8 has minimal effect on performance for gaming, as in under 1%. Gamersnexus has a piece on this and I imagine others have tested it as well.
This does happen, but I haven't noticed any performance difference with my 1080Ti running at 8x.

(I have 4 M.2 drives using up 16 lanes and then my GPU uses my final 8 lanes.)

I don't have a GPU that can be used in Gen4 PCI-E yet, but I suspect that if you have a gen 4 motherboard and your GPU can support Gen4 it would be even less of an issue.
 

martbean

n00b
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I was going to start a new thread but have pretty much the same question so thought I'd post here.

My mobo has one M.2 slot which is in use. I'm looking at adding a second M.2 drive for storage and was considering the same StarTech adapter as the OP. The PCIe slots I have are, according to the manual:

  • 2x PCIe 3.0 x16 slots (PCIE_2, PCIE_4)
    RYZEN series processors support x16/x0, x8/x8 mode 7th Gen A-series/ Athlon™ processors support x8/x0 mode
  • 1x PCIe 2.0 x16 slot (PCIE_6, supports x4 mode)*
  • 3x PCIe 2.0 x1 slots
* PCI_E6 slot will be PCIe 2.0 x1 when installing device in any PCIe x1 slot.

Am I right in thinking that if I use the PCIe 2.0 x16 slot, that should provide more than enough throughput for an average NVMe M.2? And if I'm reading that correctly it shouldn't affect the graphics card in the PCIe 3.0 slot?
 

TheSlySyl

[H]ard|Gawd
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*You'll be limited to about 1800MB/S if using an x2 slot, but it should function fine otherwise as long as it provides enough power.

*I did this with one of my nvme drives for years before I upgraded my Mobo.

Edit: Read the question wrong. I was thinking of putting a PCIE 3 nvme in a 2x slot instead of a 4x slot, not sure what would happen in a 2.0 slot.
 

Happy Hopping

Supreme [H]ardness
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6,927
I can only advise NOT to consider SilverSTone. I have some problem w/ their adapter, many coping error when i copy from the SATA side to the NVMe side of the same adapter
 
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