4090 blocking PCIE slots

[techfan84]

Hi All,

 

I am planning a dual 4090 GPU build and am seeking advice about not blocking PCIE slots with these large cards. I would like to use a Supermicro H13SSL-NT motherboard in a Sliger CX4728 chassis.

 

I was considering the following riser cables in the hopes that they can fit underneath the 4090s to make use of the blocked slots:

amazon.com.au

PCIE 4.0 X16 Riser Cable, High Speed PCIE 4.0 X16 Extender Riser Cable Dual...

PCIE 4.0 X16 Riser Cable, High Speed PCIE 4.0 X16 Extender Riser Cable Dual Reverse Ultra PCIE Riser Cable High Speed Vertical Mount for Gaming : Amazon.com.au: Computers

 

But I’m not sure if that is feasible or if it would cause performance/thermal issues.

Has anyone else encountered this problem or have suggestions?

 

Thanks a lot for your help!

[Alex Atkin UK]

29 minutes ago, techfan84 said:

Hi All,

 

I am planning a dual 4090 GPU build and am seeking advice about not blocking PCIE slots with these large cards. I would like to use a Supermicro H13SSL-NT motherboard in a Sliger CX4728 chassis.

 

I was considering the following riser cables in the hopes that they can fit underneath the 4090s to make use of the blocked slots:

amazon.com.au

PCIE 4.0 X16 Riser Cable, High Speed PCIE 4.0 X16 Extender Riser Cable Dual...

PCIE 4.0 X16 Riser Cable, High Speed PCIE 4.0 X16 Extender Riser Cable Dual Reverse Ultra PCIE Riser Cable High Speed Vertical Mount for Gaming : Amazon.com.au: Computers

 

But I’m not sure if that is feasible or if it would cause performance/thermal issues.

Has anyone else encountered this problem or have suggestions?

 

Thanks a lot for your help!

I don't see how risers are going to help, where will you physically put the cards in the case?

[techfan84]

Thanks for your feedback, looks like this is a harder problem than I was hoping... I have already purchased the chassis so am a bit stuck with it unfortunately. By getting the deeper 4728 version, I hoped there would be more options to work with. 
 

I was considering mounting a 4090 on each of the first and last slots. This should hopefully leave the middle slot available, and then I want to find a riser cable that can liberate the two blocked slots (one per card). These blocked slots would be used for SAS and NVME expander cards and require no external connections. In that case, is it possible that I can mount these cards somewhere internally (eg. even with some custom mount/3D printed thing so they don't electrically short out) since they don't need external cable access and their thermal requirements should not be too extreme? 

 

Another idea is to route at least one of the 4090s with a riser cable and find somewhere custom to mount that in the case, thus only blocking one slot at least. I have heard vertical mounting of GPUs is possible, for example, but am not sure if this makes sense in my chassis? 
 

[Robchil]

waterblock them... 

[techfan84]

I will keep this option in mind. Personally I would prefer to not do water cooling as in my mind it would require more maintenance and have added points of failure. But I expect they are more reliable than the impression I have so it is likely a very good option.

 

If it all possible though, I would like to avoid it. Do the proposals in my previous comment seem feasible to anyone with experience in this area?