It's hard to see what the contact is like, that said, I'm no expert but from what I know, the main power mosfet's are mostly towards the inner part of the card, and that mosfet appears to be at the outside corner, likely not a high power mosfet, thus some cooling should be adequate? It might even be a controller chip, from where it seems to be located?

If you're still concerned, you could get a thicker pad and replace it where it seems to have little contact. You'll know even more since it was together and you can look at all the contacts and see how they all were...

But others with more experience should be along soon...


BTW that's a great looking block!

 

It's hard to see what the contact is like, that said, I'm no expert but from what I know, the main power mosfet's are mostly towards the inner part of the card, and that mosfet appears to be at the outside corner, likely not a high power mosfet, thus some cooling should be adequate? It might even be a controller chip, from where it seems to be located?

If you're still concerned, you could get a thicker pad and replace it where it seems to have little contact. You'll know even more since it was together and you can look at all the contacts and see how they all were...

But others with more experience should be along soon...


BTW that's a great looking block!

I already use a thick thermal pad - 1.5 mm thickness. The problem is a design flaw : the waterblock by design is too short and covers only partially the last mosfet.

It is definitely a mosfet.

 

Machining quality looks really good for the price.
Which mosfet is uncover? Cant tell from your photos

My uneducated comment is the water channels, chamber and fins seems small for a 600W cooling, no?

 

The mosfet is the last one, in the lower corner on the right of the card.

For the cooling efficiency, I don't know but it seems OK : 43 fins, 0.5 mm thick, and 0.3 mm interval betweens the fins.

 

Youd probably want to use thermal putty with the clearances like that.

 

I measured 6 mm between the mosfet and the waterblock : will 6 mm thermal putty be efficient enough to evacuate the heat ? I own some Upsiren UTP-8 putty.

 

maybe try to find a copper spacer ?

 

I came up with this PCB for your card?

And I'm assuming this is the corner of the card in question?

And the component in question is the mosfet (in red) and not the inductor (in blue)?

If so, from what I have gathered, 5090's have power stages using 80-amp mosfets, With a 24-phase VRM, each power stage in the RTX 5090 would handle a portion of the total power. If the RTX 5090 consumes 575W, each phase could be handling roughly 24W. However, with the higher TDP of 600W, each phase could be handling closer to 25W, so you need at least 25W or more of mosfet cooling each, at max power draw...

 

Yes, that's the mosfet in red.

I put thermal putty on it (UTP-8). So far, everything works fine.

 

Hmm Odd. I wonder if Barrow's quality has gone down. I had a Barrow block for my Vega 64 and it was tremendous. All the FET's were covered perfectly and even at over 450watts everything was perfect. I now have the Bykski 7900XTX block.

 

I had Bykski waterblocks on my 6900 XT, RTX 4090 and 7900 XTX. I was very satisfied with their quality. Unfortunately, on this generation, Bykski strongly increased its prices - 210 $ - for their waterblocks ! As expensive as Alphacool !

Barrow manufacturing quality is good but their quality control must be improved.

 

FInally, I returned the waterblock to Aliexpress France : I found another design flaw which is a bad contact between the GPU and the waterblock : the GPU temperature is far too high, 25°C above the water temperature under a 600 W load (Furmark) which makes around 50°C. With my high-end watercooling setup, I should have obtained a delta of 10°C instead of 25°C (4 Mora-3 420 Pro and a flow of 320 l/h). I assume that the problem comes from the absence of a plate just behind the GPU : only 4 screws + springs surround the GPU which is not enough for a good contact for the large 5090 chip.

I looked at the Alphacool block but it has a design flaw too : the 2 upper RAM mosfets and 1 chip at the bottom are not cooled by the waterblock. Only 4 RAM mosfets are watercooled instead of 6 (RTX 5090 MSI Ventus 3X OC + AlphaCool Water-Block INNO3D X3 OC ist Kompatible! at 2 min 55 s and 5 min 30 s.)

According to the Byksi pictures on Aliexpress (Bykski GPU bloc de refroidissement pour INNO3D Geforce RTX 5090 D X3 carte vidéo refroidisseur d'eau plaque arrière PC Cooing radiateur N-ICH5090DX3-X - AliExpress ), every component is cooled. And since my experience with Bykski waterblocks was good, I will try this one.

 

I looked at the Alphacool block but it has a design flaw too : the 2 upper RAM mosfets and 1 chip at the bottom are not cooled by the waterblock. Only 4 RAM mosfets are watercooled instead of 6 (RTX 5090 MSI Ventus 3X OC + AlphaCool Water-Block INNO3D X3 OC ist Kompatible! at 2 min 55 s and 5 min 30 s.)

How do you see that exactly?
Also, are you sure you know what you are talking about? There is a discussion here that says they are voltage controllers and not ram mosfets:

 

Hey, these are coolers for the 5090 D (china version). And you appear to have a western 5090 Ventus. Are you sure the PCB are exactly the same?

On the bad resolution PCB picture on Aliexpress the chip parts look to be the same, but i do spot some differences to your PCB

EDIT:
The exact same Bykski waterblock is sold both for western 5090 Reference Layout cards and the Inno3d / MSI 5090 D models. So they must be the same after all.

 

No, the PCBs are the same : on the left, I have these holes too, on my photograph there are screws for the 3-slots plate. And in your upper red circle, the connector is black on the Ventus instead of white on the Inno3d.

 

Concerns about 5090 Reference block covering all components

There have been concerns in other forums that the 5090 Reference block does not cover everything it should and was wondering if I could get some clarity on the issue. Specifically: "I looked at the Alphacool block but it has a design flaw too : the 2 upper RAM mosfets and 1 chip at the bottom...

forum.alphacool.com

 

The Alphacool answer was obvious, they would not acknowledge that their waterblock has flaws.

If you don't trust the video I linked, buy the Alphacool waterblock. For me, spending 200 € on a waterblock which does not cool every component is unacceptable.

 

Can confirm AC reference block is missing the 2 points, what i did was to smear putty on them to joint with the other 2 point that make contact with block, hoping for some heat transfer.

Maybe why my vram temps are +12c above the core, while other AC block like astral have much lower delta here. does nvidia temp sensors also read mosfet temp as hotspot?

I think it’s possible to switch around, get pny block for reference ventus, since pny block is updated to cool all vrm! The mounting points seem identical, there is just longer acrylic and backplate cosmetics

reference block on pny 5090

 

Can confirm AC reference block is missing the 2 points, what i did was to smear putty on them to joint with the other 2 point that make contact with block, hoping for some heat transfer.

Maybe why my vram temps are +12c above the core, while other AC block like astral have much lower delta here. does nvidia temp sensors also read mosfet temp as hotspot?

I think it’s possible to switch around, get pny block for reference ventus, since pny block is updated to cool all vrm! The mounting points seem identical, there is just longer acrylic and backplate cosmetics

reference block on pny 5090

Good idea!

Could someone do me a favor and circle the ones that are not covered? So far I can only tell from this thread about the one at the bottom right. Then I will add thermal putty too to be on the safe side.

Also, do any of you know what versions of the WireViewPro fit this waterblock by chance?

 

Nice... a 16C delta is really good, 2 questions though (sorry lol)
What 90 degree adapter is that?
What thermal paste is on the GPU die?

 

90° adapter : Adaptateur d'alimentation 600W 12 + 4 broches PCI-e 5.0 16 broches, Angle droit de 90 degrés 16 broches 12VHPWR GPU connecteur mâle à femelle pour RTX 3090Ti - AliExpress 7

The Bykski waterblock GPU plug room is narrow, only narrow and high adapters fit. This one is adequate.

Thermal paste : liquid metal LT-100 (Pâte métallique conductrice thermique, graisse pour CPU GPU liquide de refroidissement ultra 128W/mK 1.5g 3g - AliExpress )