GPU GPU+x16 to 4x m.2 pcie x4 adapter bifurcated limits?

Windfall

I'm a huge fan of SFF
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Nov 14, 2017
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So, I would use that Asrock x570 TB3 board, and use an amerirack riser.

I would use a WS GPU- undecided between quadro p1000/2000 and AMD WX 4100/5100

The x16 to m.2 adapter is this thing on newegg from ASUS, which has 4 m.2 slots. I want to populate it with cheap-as possible mass storage (but that's not important)

What's important is that that asus thingamagadget has 4x m.2 pcie x4 slots, which is x16 bandwidth right?

And I'm using bifurcation to run this and a gpu off the board, which runs 8x/8x bifurcation.

So will I run into bandwidth issues/not be able to write to any more than two of those drives at a time? (was planning on running them in striped raid)

The asus thing's specs say "PCI Express 3.0 x16 interface, compatible with PCI Express x8 and x16 slots", but it doesn't say if that limits how many drives I can use.

I hope I made it clear enough. I'm tired, and "thingamagadget" is not very descriptive.

Thanks y'all are great ❤
 

Windfall

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So based on an Amazon review, it appears that the motherboard needs 4xpciex4 bifurcation for the card to work...

anyone have any input?

Amazon product
amazon doing some weird embed thing so here's the link in a spoiler:

amazon.com/ASUS-M-2-X16-V2-Threadripper/dp/B07NQBQB6Z#customerReviews

EDIT: Based on this I'll only be able to use two drives... -_-
 
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Cristian

Cable Smoosher
Jan 12, 2019
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I have an Asus z370 MB with 2 slots x16, wired to the CPU, that supports bifurcation . In the MB manual it's a description for how to use the Hyper m.2 x16 card . If you opt for 8x and 8x , only 2 nvme drives will work .
 

Windfall

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I have an Asus z370 MB with 2 slots x16, wired to the CPU, that supports bifurcation . In the MB manual it's a description for how to use the Hyper m.2 x16 card . If you opt for 8x and 8x , only 2 nvme drives will work .

Okay, that is annoying.

I might just put a thunderbot card in it.

If that will work...
 

Cristian

Cable Smoosher
Jan 12, 2019
11
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Check your motherboard manual. It all depends how it can bifurcate the pci lanes. Consumer mb don't have the flexibility of server boards .
 

Cristian

Cable Smoosher
Jan 12, 2019
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2
I dont have the board yet. I was going to use the Asrock X570 ITX TB3.

" * Supports PCIe riser cards to extend one x16 slot to two x8 slots if you install AMD Ryzen series CPUs " , taken from the manual on Asrock site . I think you can't use the addon card (Asus Hyper M.2 x16 ) with this MB
 

Windfall

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" * Supports PCIe riser cards to extend one x16 slot to two x8 slots if you install AMD Ryzen series CPUs " , taken from the manual on Asrock site . I think you can't use the addon card (Asus Hyper M.2 x16 ) with this MB

Yeah, that's the conclusion I've come to. I wonder if I could use a gigabyte titan ridge card instead and run TB external storage.
 

Windfall

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If I were you I'd run the motherboard in x4/x4/x4/x4 mode, use the 4 x M.2 bifurcation card and put a PCIe riser in one of the m.2 slots. https://www.aliexpress.com/item/32833359557.html your low end workstation GPU will be happy with x4 bandwidth, the difference even on an GTX 1080 is negligible https://www.techpowerup.com/review/nvidia-geforce-gtx-1080-pci-express-scaling/24.html

So the mobo will run 4x4 mode? That might just work, but I wanted 4 M.2 slots...
Argh I hate these tradeoffs
 

chx

Master of Cramming
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May 18, 2016
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You have 16 PCIe lanes. Bifurcation is just reorganizing them how they are organized into slots. If you want more lanes you will need a PCI Express switch somewhere which are costly and won't give you more bandwidth. You could bifurcate into x8 / x8 https://peine-braun.net/shop/index.php?route=product/category&path=59 and run a PCIe 8->4x4 switch from one of the x8 ports Amazon product B07KFX8287 on Amazon in case the forum inlining breaks.
 
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Cristian

Cable Smoosher
Jan 12, 2019
11
2
So the mobo will run 4x4 mode? That might just work, but I wanted 4 M.2 slots...
Argh I hate these tradeoffs
I'm not sure for AMD but intel chipset z370/390 doesn't support 4x4 configuration . If you use the asus adapter card in x16 mode you can have only 3 Nvme drives x8/ x4 x4.
Look for an adapter card that has a PLX chip if you must have 4 nvme drives on CPU support
 
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