Thoughts on unorthodox GPU mount ? (et alia)

[ioverclockers]

Hi, I finally decided to mod my Lian Li O11DXL with a front intake (see my other post). That makes me have (all fans are bequiet! silentwings 3 120mm pwm) 3 of them for intake and one of them for exhaust (2 will replace the 140mm Zalman CPU cooler).

Now I kinda gave up the idea of a vertical GPU mount. Basically, contrary to my initial thoughts (and the rationale of buying the Lian Li raiser kit), most tests I've seen conclude there's almost no difference in temps and that it's basically an esthetic issue, to "show off your graphics card"... . I couldn't care less.

Now, i do intend to replace the stock heatsink with a morpheus II core one (that will drop the temps !), but would like to be able to have access to the remaining PCIe slots on the mobo (which I shan't have if I do a regular GPU installation in the 16x PCIe slot under the CPU heatsink).

So... i was wondering : why not simply clip the GPU (radeon VII) +morpheus on 2 or 3 120mm fans that I pin directly to the bottom (which is perforated anyway and has dust filters I could simply take out to improve the airflow) and use that as a direct exhaust ?

I'm aware that most people would use these fans for intake, in order to have the air getting directly to the pcb, but that would have the hot GPU air whirl up and get to the CPU before getting to the back exhaust...

Anyway, in my proposed configuration, the GPU would still get (some) fresh air from the 3 front fans anyway and as all hot air will be pulled down directly (I thought of 3 fans instead of 2 just so that the exhausted hot air can't get back in through the 'hole' that'd be left in the bottom) and can't get in the case nor the CPU in any way...

This would have course imply I need to buy a long enough PCIE4 raiser cable (if anyone knows of a good one, feel free to let me know), so it could still get over the other PCIe cards I would like to install...

The only drawback I see, is that the GPU isn't very much solidly attached to any frame that keeps it in place (just the two clips of the fans). So, maybe some sort of mounting rail or frame that'd allow for such a horizontal mount that I could fix to the bottom plate might be a good idea ? I simply don't know of any such beast on the market, so here again, if anyone knows of such a solution, please feel free to share it !

Personally I've only found these ones :
https://www.amazon.com/dp/B07Y43C9XD
https://www.amazon.com/dp/B07Y449XHG

Thanks for any feedback on all of this...

Here's a pick to make sense of it all :
https://imgshare.io/image/N5Yery

 

[ioverclockers]

AFAIK, it's just the upper 16x PCIe slot that doesn't share any connectivity with the M.2 ones or certain SATA ones, so I'd actually prefer to keep that one for the GPU for maximum performance.

Having a cable from the first slot go over add in cards would be less than ideal.

Why so, if it's long enough?

Like this one :
https://www.amazon.com/LINKUP-RX570...rds=PCIE4EXT11SS-040-v2&qid=1593010874&sr=8-1

 

[ioverclockers]

Potential for issues

Can u elaborate ?

Would also appreciate feedback on the proposed GPU mount itself. How's the idea ?

 

[ioverclockers]

Hi thanks for the feedback.

Firstly, do you actually have plans to use other expansion slots?

yes. For sure the 1x one for my wifi/bt card and probably another one for a PCIe=>usb one.

It could work ok as intake - is there a reason you don't want to do that?

Primarily in order to avoid having the hot air whirl up to the CPU before exiting the case.

In general though I also would suggest just using an 8x slot.

Why so ? Normally it's recommended to put the GPU in the 16x slot no, to give it max performance ?

I suppose it'd help to know your motherboard model...

ASUS ROG Crosshair VIII Hero (wifi)

Extra question : would it be better to put 2x120mm fans underneath the GPU or rather 3x92 or 80mm fans in order to get maybe a better coverage of the GPU ? With the 120mm fans there could be some sort of "dead zone" in the middle, where the hotspot will be...

 

[ioverclockers]

the performance difference is something like 1-3%.

even if I OC the graphic card ?

How wide is the Morpheus 2?

254x98x44mm
I could even use 92mm fans in that case.
Anyway, as you stated, whatever fans I use if I plug the GPU directly in any PCIe slot in the mobo, the hot air is ought to whirl inside the case anyway...

 

[ioverclockers]

According to the mobo manual, this is the breakdown of the PCIe expansion slots:

3rd Gen AMD RyzenTM Processors
- 2 x PCIe 4.0 x16 SafeSlots (supports x16, x8/x8)
2nd Gen AMD RyzenTM Processors
- 2 x PCIe 3.0 x16 SafeSlots (supports x16, x8/x8)
2nd and 1st Gen AMD RyzenTM with RadeonTM Vega Graphics Processors
- 1 x PCIe 3.0 x16 SafeSlot (supports x8)
AMD X570 chipset
- 1 x PCIe 4.0 x16 (supports x4) - 1 x PCIe 4.0 x1

So basically, does this mean that it doesn't matter in which of the x16 slots I plug the GPU ? I.e. that I'm going to get full x16 speed anyway, on condition that I don't plug any other PCIe card in one of those 3 slots ? If this is the case, I may indeed just plug it in the bottom one, freeing up the other PCIe slots. Thanks for confirming this.

If I do plug another PCIe card in one of the two x16 slots mentioned above, they both halve speeds to x8 each, right?
What happens if I
- plug the additional PCIe card in the AMD X570 chipset x16 slot ? Will that give me 2 full speed x16 PCIe devices ?
- plug the wifi/bt PCIe x1 card in the x1 AMD X570 chipset slot ? Will that somehow interfere with the speeds of the x16 slots ?

 

[ioverclockers]

hy not just get a Lian-Li GPU vertical mount kit?

i have one !
I'm just thinking of stepping back of vertical GPU mount. One of the reasons being that airflow will choke, as it's nearly touching the side panel of the case.

 

[ioverclockers]

Well, not that much...
Other thing is that the PCIe connector is PCIe 3.0 only and that I wanted to be able to draw fully from the PCIe 4.0 possibilities of my mobo. This being said, it seems that that won't make a huge difference. If this is the case, I might revisit the vertical mount. Just afraid that the GPU+morpheus cooler+2 fans will be a bit too bulky for a vertical mount...
I'm trying to find out the shared connectivity between the PCIe slots and f.ex. my 2 M.2 slots and SATA ones in order not to loose too much potential...

 

[ioverclockers]

Not sure I understand what you mean by "too bulky for vertical mount".

What I meant is that the combination of the GPU with both the heatsink and fans will be quite space hungry :
RADEON VII
267 x 121 x 40 mm
MORPHEUS
254 x 98 x 44 mm
BEQUIET! SILENTWINGS 120mm
120x120x25
TBH, I don't know how modding the GPU with the morpheus will affect total diameter, but it'll certainly encroach into my bottom PCIe 16x slot and probably the PCIe 1x one just above...
Wasn't referring to sagging issues here.

 

[ioverclockers]

You'd want those bottom fans to be intake wouldn't you?

yep.
I have modded the case to allow for frontal intake (3 fans) and one exhaust fan. There's parts of the case that allow for passive exhaust too. That should be enough.
The other option I was thinking about (cf. title of post) would be to simply place the whole horizontally on the bottom plate that allows for intake. That would require an extender cable but would allow for using the other PCIe slots on the mobo (this does mean I'd have the extender cable hanging over other PCIe cards, that's true...).

 

[ioverclockers]

So basically GPU is about 20m thick + Morpheus 44mm + 25mm for fans =89mm + at least 30mm for good airflow to fans, more is definitely much better.

Clearance between bottom plate and mobo is 8 cm. If I give up bottom PCIe slot (I need to keep the x1 slot) I might get like 11 or 11,5 cm max, so it'll be a close call really. Guess I will only be able to find out after mounting the whole thing...
What would be your thoughts on mounting the GPU horizontally but with an extender cable ? I'd simply fix the fans to the bottom plate that has holes so that'd be ok for direct intake. Width of bottom structure (to fix the fans) is larger than width of GPU, so that's ok. Depending on final hight of gpu+morpheus+fans I might have a little bit more clearance towards the mobo (not much though)...
Would you advise like 2x 120mm fans or rather 3x 92mm ? Would it make a big difference as to the airflow ?
I do see Noctua has a set of slim 92 mm fans : NF-A9x14 PWM that are only 14mm thick instead of the 25mm 120mm ones, so that'd shave off a big cm already...
Would it be better to plug them in the GPU with an adapter or in the Thermaltake usb hub for the case's other fans ?

 

[ioverclockers]

Sorry, don't understand what you mean by mounting it horizontally. To me normal mounting to motherboard is horizontal.

Well, that's exactly the orientation I intended. Instead of plugging it into the mobo - horizontally - I thought of placing the whole - horizontally - on the bottom of the case which has vents...

If you could exchange Silent Wings 3 for Noctua NF-A12x15 fans i think I would

So basically you'd still prefer 2x120mm fans to 3x92mm ones. Is that correct ? Any particular reason for that ?

 

[ioverclockers]

you GPU is PCI-e 3.0 so your dont need a 4.0 cable

O darn... I was convinced my Radeon VII was 4.0 ! Guess I didn't do my homework correctly ...
Well, that shelves the need for a 4.0 raiser cable indeed ...
So might as well try out a vertical mount with my Lian raiser kit (cable included...) or to try out my unorthodox horizontal mount...

If you also have a look at the end of the radeon 7 graphics card thread

Can u link me to that one ?

 

[ioverclockers]

Page 130 post 2596 onwards

ok will dive into that...
Just to give me a head start, could you quickly summarize how you implemented your mods on the GPU :
- the washer mod
- cool labs liquid ultra to the core and HBM
that's liquid metal ? Ain't that dangerous for unwished electrical conductivity ?
did you simply add the copper heatsinkies that come with the GPU on top of that ?
- and changed the thermal pads to Geild extreme 12 W/mK
to replace the stock thermal pad bands that come with the Radeon ? I guess u cut them to the right proportions?

 

[ioverclockers]

Hi and thanks for all the feedback.
Ok, so fiddling with the different fan (size) options, I'm trying to make up my mind.
In order do to so, uploaded 2 pics : one with my case clearings from the bottom side up to the mobo and a drawing of the 3 possible fan sizes.
We're talking horizontal mount here (fixing the fans horizontally on the bottom of the case).
- 120mm fans
Basically, as far as capacity and noise are concerned, this would be the best pick in my opinion.
I would have to fix them on the ridge of the bottom part (which would increase overall hight 1,20 cm), but that's compensated for by the 1,5 cm hight of the fans. Thats only 2,7 cm overall (almost like a normal 25mm height fan).
It wouldn't cover the whole length of the morpheus nor the Radeon VII, but I wonder whether that's really going to be an issue if we look at the amount of air it can push through...
- 92mm fans
That would have been my second choice, but they're just 2mm too wide in order to place them directly on the bottom of the bottom part of the case (only 90mm wide). I could file those edges for 2mm, but I wonder whether it's worth the effort.
When comparing noise and capacity to the 80mm fans, surprisingly it pushes less air but produces more noise !
- 80mm
So this would be the contender (for me) for the 120mm fans.
Sure, it pushes less air and is a bit noisier, but maybe covers more of the pcb, especially in the center where the hotspot of the GPU will be.
Their size would allow me to put them directly on the bottom of the bottom part, which saves me 1,2 cm on the go.
Unfortunately, the fans themselves are 25mm thick, so I'm kinda loosing that gain to the 15mm 120mm fans...

So basically, I'm hesitating between the 120mm and the 80mm ones.
They're both PWM.
I did order a PWM adapter so I can plug them in the graphic card. So I just need a Y splitter for 2 or 3...

What would be you guys take on this ?

https://imgur.com/h4HxoSQ
https://imgur.com/bXhbDbw

 

[ioverclockers]

looks like a long thinking process

 

[ioverclockers]

Thx for the feedback. So I guess I'll stick with the 120mm fans then... Actually, the NF-A12x15 PWM is only 15mm thick, so that shaves of a centimeter already... Guess they're good enough for the job ? One remaining question is whether there would be any voltage problem plugging them in the graphic card with an adapter ? I already ordered a Gelid PWM fan adaptor for VGA coller fan, but I can always plug them in the Thermaltake usb hub if the former solution would be problematic for one reason or another...
I could also simply use 2 of the bequiet! silent wings 3 fans I have laying around, they're high speed although being 25mm thick...

 

[ioverclockers]

yea actually 25mm should be ok. Do you think the silent wings could do the job too, as I already have them laying around ? They're actually quite some beasts : 3.37x2200rpm. They're just a bit louder though...

 

[ioverclockers]

ok, any thoughts about connecting them directly to the GPU thru the Gelid adaptor? Seems more logic to have the GPU trigger them no ? Would that cause any voltage issues ?

 

[ioverclockers]

GPU Gelid adaper is powered by GPU, not PSU?

I guess so. We're talking about the PWM Fan Adaptor for VGA Cooler Fan (CA-PWM-02) https://gelidsolutions.com/thermal-solutions/accessories-pwm-fan-adaptor/. It's rather basic. It just needs a PWM y-splitter. Got a bunch of ETSAMOR 10.5 inches 4 Pin PWM Fan Extension Cable Connectors https://www.best-book-price.co.uk/p...+5+inches+4+Pin+PWM+Fan+Extension+Cable+.html. They should do the job no ?
Have been unable to find out fan information on AMD site, but Googling seems to indicate the fans are "FirstD FD8015H12S", so that would be 12 V 0.32 a. Would be good if someone could confirm this though...

Are they all running on same fan circuit?

Sorry, but don't see what you're referring to here...

Which Silent WIngs fans do you have?

be quiet! Silent Wings 3 120mm PWM High-Speed, BL070

One reason why I'm interested in plugging them in the GPU would be to take off some of the load of the Thermaltake fan hub. There's already 6 silent wings plugged in it (3 front intake, 1 rear exhaust and 2 fans replacing stock CPU cooler). I'm a bit weary of this 1a limit in the mobo header...