eGPU external video card connection

[julval]

I need to connect external RTX 3090 graphics cards to my HP workstation.


I wanted to use PCIe extension cables, but they are difficult to use since there are no external port adapters. The extension cables are not allowed to be routed through the holes drilled in the case.



Found these options:


x16 PCIE extenders

https://vi.aliexpress.com/item/1005006752061032.html
https://vi.aliexpress.com/item/1005004028133937.html
https://vi.aliexpress.com/i/1005006015381652.html

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MCIO 8i SFF

https://vi.aliexpress.com/item/1005008314444335.html

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SFF-8654 8i external ports

https://vi.aliexpress.com/item/1005007905897457.html
https://vi.aliexpress.com/i/1005006174381598.html
https://vi.aliexpress.com/item/1005008407928907.html

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SFF-8654 8i internal ports

https://vi.aliexpress.com/item/1005008471040412.html
https://vi.aliexpress.com/item/1005007217978501.html

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SFF-8654 8i internal ports
https://c-payne.com



Using adapters is beneficial because it allows you to split x16 pcie into 2x x8 ports. But the price is much higher. Who used these cards, do they work? As far as I know, they are not interchangeable. (https://watchmysys.com/blog/2024/10/gigabyte-mj11-ec1-pcie-bifurcation/)

[philipma1957]

you need to ask this in altcoins

i will ask mods to move it


https://bitcointalk.org/index.php?board=160.0

gpus are used for alt coins not btc.

someone may know in that section


https://www.aliexpress.us/item/3256807719582705.html?gatewayAdapt=vnm2usa4itemAdapt

never used it but it appears to me it would give you a fully operational rtx 3090 outside of the case.

it also looks like you could use a separate power supply for the cards.

as I think it may isolate the cases power supply.

be very careful
 hooking up the external cards if you use a second power supply.

I ask mods to move this to altcoins

there are people there that know more than i do

do not rush to do this

[julval]

Thank for reply, I wonder how there PSUS did not damage anything.

external psu
https://www.newegg.com/visiontek-juice-box-vt-450cd-450w/p/N82E16817206001
https://www.newegg.com/fsp-group-booster-x5-450w/p/N82E16817104054
https://www.jagatreview.com/2010/12/review-thermaltake-power-express-650-%e2%80%93-affordable-power-for-your-high-end-graphics/3/

The manufacturer of CNS52CX16R Ceacent said that the:

"The SFF8654 to SFF8654 cable does not provide power transmission. If you don't connect the power supply to the CNS52CX16R, it will not work and your GPU device will not be recognized by the system."

So the SlimSAS cables are just for data lines. Can anyone confirm this?

[FP91G]

I have a question: How many video cards do you want to connect and for what purposes?
I saw a lot of adapters, but I don't understand your goal.
If you need to connect 1 RTX 3090 video card, then I would use something like this or similar
https://aliexpress.ru/item/1005003095354827.html
But if we are talking about 2-4 video cards, then I would not use adapters on such hot video cards, it is not very safe.

[julval]

Thank you for reply, your suggestion allows 1x speeds only.

I want to connect 4 GPU's RTX3090 at x16 speeds. With possible upgrade to 8 at x8 speeds.
The mother board supports bifurcation. This for running Ai like deepseek.

The workstation currently has 2x 3090 installed into the case, does not fit anything more.
So I have purchased enclosures to the remaining 2x 3090.

The additional external PSU will be 850W to be able to run both external cards.

The problem is I can't find any adapters for eGPU that would even have external connections SlimSAS SFF-8654 74pin.
The only card is https://i.postimg.cc/rFnmKrD6/egpu5.png and it has noname manufacturer, no retimer chip if it's even needed is another problem.

The more reputable brands like Ceacent have only cards with internal ports, (so far they can't answer if is isolated, claims so)
If you search for SlimSAS SFF-8654 74pin bracked IO you will find none. So why these ports even used for eGPU then what kind of scam is this? Why even bother making MCIO ports looks the same but are not the same.
Somebody does standardize this nonsense, the Chinese did not invent this SlimSAS SFF-8654 74pin etc.

CEACENT CNT42PE16 is a retimer board that should be the best I could find, you can find more expensive ones like from minerva.com.tw but they make 350USD minimum boards that is nonsense price.

Now need to find adapter to convert internal ports to external similar to this: but for  SlimSAS SFF-8654 74pin to  SlimSAS SFF-8654 74pin female to female
https://www.walmart.com/ip/JSER-Dual-Ports-Mini-SAS-SFF-8088-To-SAS-36Pin-SFF-8087-PCBA-Female-Adapter-With-PCI-Bracket/2167148435
https://www.genuinemodules.com/cvt-8643-8644-2ch

Any help?

[FP91G]

Then you need a special motherboard that supports PCIE 4x16 and 8x8 and a good processor that supports the required amount of PCIE.

You have chosen a very difficult path and most likely you will have to go it alone

[julval]

Then you need a special motherboard that supports PCIE 4x16 and 8x8 and a good processor that supports the required amount of PCIE.

You have chosen a very difficult path and most likely you will have to go it alone

I have Z8 G4 with 1700W PSU, you cant get more special then that I use 2 GPU from main PSU already. There are better boards with EPYC and all MCIO ir smilSAS connectors (no actual PCIE ports), but that is with DDR5 mostly. For somebody with unlimited money maybe good solution there are videos about it already.