Has anyone tried to use pci x1 to x16 riser for Nvidia Iray?

https://www.amazon.com/dp/B09R8VDRCB?psc=1&ref=ppx_yo2ov_dt_b_product_details

So, since I bought a 4090 my 3090 was sitting in a box and I bought one of these adapters, that are usually used for mining, cause I want to render with a 4090 + 3090 in Iray.

I got to the point where Device Manager and the Advanced tab in the Daz render settings sees the 4090 and 3090 but if I try to use them in a render, it bounces to cpu. If I unselect the 3090 then the 4090 will render.

Has anyone got this kind of rig to work or should I give up this angle of attack?

(I didn't mount the 3090 directly onto my motherboard inside the case because my case isn't big enough and my PSU isn't powerful enough. I had a 650 watt PSU in storage that I am trying to use for the 3090 externally).

Comments

  • crosswindcrosswind Posts: 6,986
    edited May 2023

    I don't think that Riser is gonna work at least for rendering. I have 3 cards, for better cooling what I'm using for one of them is a 'side mount' like this: https://www.amazon.com/ASUS-ROG-Flexible-Extender-Extension/dp/B082G52H1L/ref=sr_1_8?keywords=pcie+side+mount&qid=1684363990&sprefix=pcie+sid,aps,307&sr=8-8. The card has to be plugged in or connected to the PCI socket on the MB..

    Post edited by crosswind on
  • Saxa -- SDSaxa -- SD Posts: 872

    Impression is unless you have NVlink that pooled VRAM (mainly only textures) that is useable by Nvidia's Iray, hence DS, it otherwise becomes an either-or proposition.

  • DiasporaDiaspora Posts: 440
    edited May 2023

    "I don't think that Riser is gonna work at least for rendering."

    Yeah, I get the impression that mining can work for x1 to x16 because perhaps it has something to do with how the mining software gets off loaded onto the GPU?

    But yeah, maybe for Iray, the GPU plugged directly into the motherboard is the only way. Because the 2080 was cool enough and small enough, I used to use a 2080+3090 rig with both cards plugged directly into the motherboard, which is the only time I ever got multi-gpu Iray rendering to work. 

    The 3090 is such a big hot card though, I would need a whole new case and psu, not sure if it's worth all that trouble....

    Post edited by Diaspora on
  • crosswindcrosswind Posts: 6,986

    Diaspora said:

    "I don't think that Riser is gonna work at least for rendering."

    Yeah, I get the impression that mining can work for x1 to x16 because perhaps it has something to do with how the mining software gets off loaded onto the GPU?

    But yeah, maybe for Iray, the GPU plugged directly into the motherboard is the only way. Because the 2080 was cool enough and small enough, I used to use a 2080+3090 rig with both cards plugged directly into the motherboard, which is the only time I ever got multi-gpu Iray rendering to work. 

    Yea, 4090 is 'too big'... if there's no space to hold both of 3090 and 4090, just go for a bigger case devil

  • Saxa -- SDSaxa -- SD Posts: 872

    Diaspora said:

    "which is the only time I ever got multi-gpu Iray rendering to work. 

    So sounds like speed was more important than capacity with vram limited to smallest card capacity?

    Is good to hear that DS users trying to find work-arounds.  Would be awesome if a way was found giving both speed and more memory capacity.  Especially now that NVlink is deprecated with 4k series.

  • Saxa -- SDSaxa -- SD Posts: 872

    crosswind said:

     just go for a bigger case devil

    lol, what would that look like.

  • crosswindcrosswind Posts: 6,986
    edited May 2023

    Never waste 10K+ Cuda cores... but necessary upgrade of hardware is needed, PSU, case, etc.

    Post edited by crosswind on
  • Saxa -- SDSaxa -- SD Posts: 872
    edited May 2023

    Could probably heat your room with those 10k +

    And in a summer heat dome, that would be 'fun' smiley

    edit: have those upgrades - but already have issue with heat generated by 1x3090xtreme.  Hopes for next gen 5k series.

    Post edited by Saxa -- SD on
  • crosswindcrosswind Posts: 6,986
    edited May 2023

    Saxa -- SD said:

    Could probably heat your room with those 10k +

    And in a summer heat dome, that would be 'fun' smiley

    Unfortunately that's true,  so while the cards are fully loaded for rendering, so is the air conditioner. blush

    PS: if the case is big enough, better serve the cards with some cooling system though I don't have... no more space loh

    Post edited by crosswind on
  • PetercatPetercat Posts: 2,321

    Diaspora said:

    "I don't think that Riser is gonna work at least for rendering."

    Yeah, I get the impression that mining can work for x1 to x16 because perhaps it has something to do with how the mining software gets off loaded onto the GPU?

    But yeah, maybe for Iray, the GPU plugged directly into the motherboard is the only way. Because the 2080 was cool enough and small enough, I used to use a 2080+3090 rig with both cards plugged directly into the motherboard, which is the only time I ever got multi-gpu Iray rendering to work. 

    The 3090 is such a big hot card though, I would need a whole new case and psu, not sure if it's worth all that trouble....

    Could you do with just a larger case and use your second PSU externally to power the card?
    As for heat, all of my case exhaust fans (two top, one rear) are ducted to vent outdoors in warm weather.
    It's ugly, but it works. There's still a little bleed out through the case seams because the case is
    pressurized, but it's negligable.

  • KitsumoKitsumo Posts: 1,216

    It works. My memory is kind of fuzzy, but from what I can remember, I had to go into the BIOS and set the main (big) PCIE slots at a lower speed to free up resources for the 1x PCIE slots.

    I imagine mobo makers set the default for the big slots to get all the bandwidth because how many people actually use those small slots?

  • DiasporaDiaspora Posts: 440

    "Could you do with just a larger case and use your second PSU externally to power the card?"

    From what I've read, you can't power hardware from two different PSUs.

    What I mean by that is that the 3090 in this hypothetical configuration would be getting 75 watts from the PCI Express slot that is getting power from the internal PSU and the rest of the wattage from the external PSU, and that's a big no no because of something to do with the flow of electricity (I'm honestly not sure why or how it works).

    Someone with more knowledge on this can educate me if I'm wrong but while doing my own research, I found that miners specifically use these powered risers because the riser and the card, that way, get power all from the same place. 

  • DiasporaDiaspora Posts: 440

    "I had to go into the BIOS and set the main (big) PCIE slots at a lower speed to free up resources for the 1x PCIE slots."

    Thank you for the lead, I still have everything hooked up despite my earlier disappointments, I'll try out what you suggested and see what happens. 

  • KitsumoKitsumo Posts: 1,216

    In my setup I had a separate power supply for the cards. In the first pic in my post, you can barely see the power supply at the bottom of the milk crate.. uh server chassis. So the PCIE riser cards are connected to the motherboard, but the additional 6 or 8 pin power to the cards is coming from that other power supply. I plugged both power supplies into the same wall outlet.

    I bought one of those ATX power supply control cables on Amazon so both would power on at the same time, but that thing didn't work. Then I just googled "run power supply not connected to motherboard" and found out how to do it.

  • DiasporaDiaspora Posts: 440

    Tsk, damn, I don't know if it's a limitation of my bios or what is going on but I just cannot get my 3090 to work with Iray. 

  • crosswindcrosswind Posts: 6,986
    edited May 2023

    Diaspora said:

    Tsk, damn, I don't know if it's a limitation of my bios or what is going on but I just cannot get my 3090 to work with Iray. 

     PS: maybe you can attach the Ds log file down below, we may give it a check... (from opening Ds to fallback to CPU)

    Post edited by crosswind on
  • DiasporaDiaspora Posts: 440

    I don't think it's a DAZ Studio issue, I notice when I open GPU-Z and select the 3090, many of the fields that should be there aren't and nearly all are empty, I don't think my computer can really talk to the 3090 in this configuration. 

  • crosswindcrosswind Posts: 6,986
    edited May 2023

    Diaspora said:

    I don't think it's a DAZ Studio issue, I notice when I open GPU-Z and select the 3090, many of the fields that should be there aren't and nearly all are empty, I don't think my computer can really talk to the 3090 in this configuration. 

    Hmm ~~ if GPU-Z is not able to show the data and those 'peak value' as usual, I still think it might be the connection problem. The reason why I suggest you attache the log is because the log may show some information of your card status when opening, rendering, etc. Perhaps there'll be some clues...

    Post edited by crosswind on
  • oddboboddbob Posts: 396

    Diaspora said:


    The 3090 is such a big hot card though, I would need a whole new case and psu, not sure if it's worth all that trouble....

    An Alphacool Eiswolf 2 AIO would make the 3090 smaller and quieter, how much PSU do you have?

  • DiasporaDiaspora Posts: 440

    Maybe I'll try a different riser because something I've read is that a lot of these mining x1 to x16 risers tend to be defective and a lot of miners will just sort of buy a pack of multiples and swap them out until they find a good one. 

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