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Converting my EVGA RTX 3090 XC3 Ultra to a hybrid, and a few other tweaks

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ratbuddy

Member
Joined
Aug 24, 2007
I've been gathering parts for this project for a few weeks now, and tonight was finally the night. Took me five hours start to finish, but I'm getting old and slowing down, and given the price of this card (let alone actually finding one; I was in the queue for 15 months to get this one), I didn't want to mess up and break anything. Anyway, the pile of parts, minus the PC where I've been running the card on air for about two weeks:

oPFbLHx.jpg


On air it got loud and hot, and the memory temps were pushing over 100, not good for longevity. Core basically went up to 83, the fans kicked up, and I had to keep power limit around 80 if I wanted tolerable sound levels. The remedy includes an EVGA hybrid AIO kit, coolmygpu.com plates for both front and back RAM (front plate at https://www.coolmygpu.com/product/hybrid/4?cs=true&cst=custom and I'm not linking the back plate because I'm not sure if it's finalized/public yet), Kriticalpads for the VRMs and inductors (this set https://kriticalpads.com/evga-3090-ftw3-hybrid which includes VRAM pads, but I didn't use these, good to have spares anyway), and some Alphacool 17427 heatsinks over the back side RMA. I am planning to actively cool the heatsinks, but didn't end up ordering the right fan to do this.

Before I started, I test fit the GPU AIO in the top spot of my Fractal Define Mini C - bad news, the fittings on the existing front MSI P240 AIO interfere, so the GPU rad won't fit in the top spot.

NXL8JnH.jpg


I had to both remount the CPU block to get the tubes on the left so I would have room for the GPU backplate heatsinks, and turn the front CPU radiator upside down so the fittings are on the bottom. During this step, I mounted Noctua A12x25 fans to both radiators. The front radiator is intake, the top one exhausts out the top of the case.

pwvvmVp.jpg


The EVGA hybrid kit (only $100 or so direct from EVGA, super value here!) came with good instructions and plenty of extra screws. It didn't take too long to strip off the air cooler and clean the old pads, putty, and paste off the card. You can see the copper plates from coolmygpu.com above the air cooler.

CucF2oa.jpg


Dry fitting the plates on the GPU block. You can see the square piece on the bottom left for the single VRAM chip on the bottom of the card, and larger copper sections for the VRAM on either side and above the GPU. The plate that comes with the EVGA hybrid cooler is unused - it uses thick thermal pads and does not cool the VRAM nearly as well as these chunky copper plates stuck together with Arctic MX-5.

hcAy7GH.jpg


Once I was satisfied that I had the plates lined up right, I removed the thermal pads that came with the hybrid kit and added the Kriticalpads pads, a nice minty green.

s2ihLHZ.jpg


Next is a heavy bead of MX-5 around the block. This is the contact surface where the coolmygpu.com plate transfers heat from the VRAM to the water block.

xxB7lOq.jpg


Then you add the larger of the two plates and squish it down, then sort of smear the paste into the cracks as best you can.

QFhTHvU.jpg


I don't have pictures of the next step, but you just put some paste on the plate and put the VRAM plate on top. Then, you apply a thin layer of paste to the GPU die and all the VRAM chips. There are no thermal pads between the GDDR6X and the water block now, just copper and MX-5.

After mounting the PCB to the hybrid cooler, I did the rear VRAM chips. These get really hot, and the backplate does a bad job of cooling them. There are some pads in there, but they are pretty thick and the flat backplate doesn't shed heat very well anyway. First step is to paste the chips, which were cleaned of thermal pad residue earlier:

dS3001x.jpg


Then line up the plate, being really careful not to hit any of the raised surface mount components. Of particular concern are some parts on the north side in the cove area; these will definitely hit the copper plate if it's too close, and I think shorting something out here would be really expensive :)

owL7m0a.jpg


Once I had it lined up and checked clearances of all the raised stuff, I added a few pieces of the supplied thermal tape, and gooped on some Kryonaut (I had run out of MX-5, probably was a little too free with it at the start of the project - you can get a 4 gram tube included with your coolmygpu.com plates at cost, and he's an authorized Arctic dealer now) to make sure the copper VRAM plate contacted the stock EVGA backplate well.

6Hx0SAA.jpg


Once I was happy with the placement of the plate, tape, and paste, I put the empty thermal paste box on the card to hold the backplate up. The supplied tape seems really, really strong, and I didn't want the backplate to stick to the copper plate in the wrong position. I put the far two screws in first so the backplate wouldn't move, then carefully lowered it onto the plate and pressed pretty hard to seat the tape. I then put in the rest of the screws.

2iBZHVw.jpg


A bit of paste oozed out, and I checked from the sides to make sure there was contact between everything.

RXJEUyC.jpg


The last step was adding the Alphacool 17427 heatsinks directly on top of the copper plate/VRAM chips, using thin but strong thermal tape. I would have used some of the Arctic Silver adhesive stuff, but I didn't have any on hand and it seems to be discontinued. Anyway, using tape means I can reverse the mods if I need to RMA the card, although if someone wanted to make a more permanent connection between the heatsinks and the card, spare backplates are available on ebay. I mounted the heatsinks oriented so a fan blowing down into the middle would blow through them. I test fitted a Noctua A8, and while it would work great, the CPU block is a little too big to allow this. I have an A6 on hand and I'll test that, but it's really tight above the GPU and I may need to either go down to a 40mm fan, or just leave it passive.

y7ZVmc9.jpg


80mm A8 test fitting; I was planning to glue flange nuts or rivet nuts to the backplate and screw the fan down to that, blocking out the corner areas with shielding so the air was forced through the fins. I don't think that's really needed at this point, temps are already great.

fj7aIma.jpg


Once I realized the heatsinks would have to be passive for now, I turned the rear case fan around and made it an intake. I don't love having an unfiltered intake fan back there, but the airflow seems to really help both the VRAM and the NVMe drive temps, so I think I'll keep it like that for now.

Ou6JI5y.jpg


Final product:

5WHcT7c.jpg


Did I mention it's a mATX case/build? Fitting both 240mm radiators in there with everything routed properly was a challenge. I think it looks nice with the copper/gold/brown/black theme, though I gave aesthetics a 0% priority - it's just how it all turned out. The RAM is Trident Z Royal, half gold half silver - there was only one of each kit in stock when I ordered it, but I think it looks nice like this.

I did a quick Furmark 4k preset run and hit GPU core 42C, VRAM junction 56C. Before I did all this, those temps were more like 83C and 100C. I'm very happy with the results.

Disclosures: I bought everything in this post myself, and I have no affiliation with any of the products or vendors in my post. I just wanted to bring attention to the coolmygpu.com plates and the Kriticalpads pre-cut thermal pad sets. I love that people are starting these small businesses to cater to people who want better thermals on their video cards, and I would like nothing more than to see both companies succeed and continue to offer these type of products for future generations of GPU. I'm also thrilled that EVGA offers an affordable official hybrid kit (made by Asetek, same as the MSI CPU AIO in my rig) for their RTX cards. I'm cross-posting this to the EVGA forums.

Thanks for reading this far, let me know if you have any questions or want me to run any tests :)
 

BugFreak

Joined
Apr 29, 2010
Location
Central FL
Looks great! I'm about to convert my 3080 to water and didn't want to pay for an ek active back plate so this might just work for me. Never heard of the coolmygpu plates so I'll look into those.
 

ATMINSIDE

Sim Racing Aficionado Co-Owner
Joined
Jun 28, 2012
Absolutely love the thought process put into this. The clearance from the upper fans to the RAM is perfect, can't believe that worked out!
Any particular reason you didn't go full custom for this?
 
OP
ratbuddy

ratbuddy

Member
Joined
Aug 24, 2007
Looks great! I'm about to convert my 3080 to water and didn't want to pay for an ek active back plate so this might just work for me. Never heard of the coolmygpu plates so I'll look into those.

Thanks, and I wouldn't even bother doing anything on the back of a 3080 - they only have VRAM on the same side as the GPU, so cooling the back isn't going to get you much.

Absolutely love the thought process put into this. The clearance from the upper fans to the RAM is perfect, can't believe that worked out!
Any particular reason you didn't go full custom for this?

The RAM, yeah, those Trident Z Royal sticks are supposed to be 44mm tall, but the crystal looking side is a little shorter, so it barely clears. The big stupid heatsink thing over the I/O shield I think touches the radiator, I need to check on that. I also have idle PCH temps around 70C, so I might need to do something other than 'big flat aluminum' in that area of the mobo.

I didn't go full custom because it seems like a pain in the butt and I don't really want to fiddle with it. Plus it probably costs more and is more prone to leaking due to my inexperience. I just wanted something cool and quiet.
 

BugFreak

Joined
Apr 29, 2010
Location
Central FL
Thanks, and I wouldn't even bother doing anything on the back of a 3080 - they only have VRAM on the same side as the GPU, so cooling the back isn't going to get you much.
I figured that out when I went to their website. I can honestly say I did not know that. I was under the impression my card had ram on the backside too. Actually happy to be wrong!
 

EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
Your GPU is blowing right down on the motherboard/chipset... I don't imagine that helps things. Oddly enough, that's warmer than mine with a heatsink and not AIO (more heat)... did you bump the chipset heatsink and unseat it? If an airflow adjust doesn't work, I'd try a paste reapply.

Maybe try firing that rear fan out to change the airflow a bit... take heat out a different path than whatever it's doing now and see if that helps. this configuration doesn't promote airFLOW so much as it does getting cold air to the top rad. Surely you have the headroom to focus more on the chassis internals. :)
 
OP
ratbuddy

ratbuddy

Member
Joined
Aug 24, 2007
Your GPU is blowing right down on the motherboard/chipset... I don't imagine that helps things. Oddly enough, that's warmer than mine with a heatsink and not AIO (more heat)... did you bump the chipset heatsink and unseat it? If an airflow adjust doesn't work, I'd try a paste reapply.

Maybe try firing that rear fan out to change the airflow a bit... take heat out a different path than whatever it's doing now and see if that helps. this configuration doesn't promote airFLOW so much as it does getting cold air to the top rad. Surely you have the headroom to focus more on the chassis internals. :)

The GPU rad is blowing up and out of the case through the top. The front rad/fans and rear fan are blowing inwards. I may open up the PSU tunnel and put a bottom 120mm intake blowing up, that would let me switch the rear fan to an exhaust. We'll see.

I have the rear fan on intake because otherwise the only fresh air is coming in through the front AIO, and I didn't want 2 intake with 3 exhaust. NVMe and RAM temps were worse with the rear fan on exhaust. I do need to check on the motherboard heatsink, the top rad is pressing (lightly) on it, but it may have unseated. Couldn't hurt reseating it with good paste anyway, I'll have the case open to test mount a 40x10 Noctua over the VRAM tonight :)
 

EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
I expect those items to be warmer, sure. But like was mentioned you have headroom for those items, versus the chipset, you don't have much. It's going to be a rob Peter to pay Paul type thing.

When you say 'motherboard heatsink' do you mean the VRM heatsink up top, I assume? Worth noting, those are thermal pads, so, you'd want to replace it with the same thickness and higher quality (fujiopoly brand), not thermal paste 'em. The chipset towards the bottom of the board is typically a thick paste that seems to harden so paste that.

I also wouldn't sweat more CFM out vs in (pos/neg pressure)... there's a negligible difference between the orientations and dust (cooling it's largely irrelevant).

Before changing the wheel, where are you getting that PCH value from? Can you confirm it against another piece of software or double-check in the BIOS?
 
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ratbuddy

ratbuddy

Member
Joined
Aug 24, 2007
I'm talking about the big stupid thing over the I/O shield, but I'm looking closer at my mobo and I think the PCH is actually down under the RAM/to the right of the PCIe slots. If I reseat and repad/paste that, plus put an intake fan in the very bottom of the case where I was planning, that should take care of that. Only downside is my cables will need to be managed more carefully down there.

I got the temps from HWInfo64:

nzBdXCT.png


I have no reason not to trust it, and some searching shows other people have similar (or higher!) temps on Asus Z690 boards. I have some really squishy 2mm 20 W/mK thermal pads around, hopefully those will work on the PCH. They should, unless it uses a .5mm pad, which I sort of doubt.
 

EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
Currently, my Z690 board's (Asus as well, Hero) PCH is running 70C too... a weird coincidence.....lol. I'm wondering if it's an Asus sensor thing with Hwinfo perhaps???? I've got a ASRock board up, but I don't see a PCH temp listed to compare.

Worth noting, my GPU is vertical and isn't blowing onto the chipset. I haven't checked in the BIOS to confirm. Another good way to check is to pay attention to the temp upon your first cold boot. If it says 70C by the time you get to windows and open up Hwinfo, I wouldn't buy it...........as you know being here for ~15 years, you should always confirm software readings with hardware (or another source) where possible. :)

Yeah, VRM heatinks are above and to the left of the socket. The chipset is located on the bottom right of the board, under your GPU. I can't imagine it uses anywhere near 2mm thick pad. Paste that thing. :)

Keep us posted!

EDIT: I just checked some datasets I have for reviews... the Aorus master PCH runs 31-35C during a CPU stress test with a 12900K at 5.1GHz/4.1GHz....

EDIT2: The Asus TUF I have, ran ~45C during the same overclocked stress test. MInd you, these were open air chassis, but a GPU sits right on top of them too.

EDIT3: The Hero ran around 55C on the test bench a couple of months back....My case is the Azza Opus without a single fan, FYI.

EDIT4: If that thing is 70C, I can touch the heatsink with my hand... it's warm, but not hot like i would expect a 70C part below it... :)
 
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ratbuddy

ratbuddy

Member
Joined
Aug 24, 2007
I just remembered I have a second of this motherboard (came in with a ton of bent pins, and I know better than to try to RMA/return it :/ ) I can go check under the PCH heatsink on that one :beer:
 

EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
lol if it came that way, you absolutely should return it. If you borked it, you have to eat it.

Not sure what you're checking there, but, I'd use paste regardless.

EDIT: Also worth noting I have shed loads of drives and USB using the PCH lanes. I have 3 M.2 drives, one SATA-based SSD and a HDD total and 6 active USB ports in use.
 
OP
ratbuddy

ratbuddy

Member
Joined
Aug 24, 2007
Yep, I can't swear that it came in that way, I just know it will only boot with RAM in the last two slots, and it has a bunch of bent pins. I didn't spot them until after I'd mounted a CPU, so I can't say for sure if it came in like that, or they were somehow bent in the three seconds I had the latch open to mount the CPU. I do know what Asus will say though, so I'm not going to waste my time trying to return it.

It looks like the heatsink is held on with plastic pushpin things, but I can't get to the back side without unmounting the motherboard. I really don't want to have to do that right now :p Maybe I'll install the bottom fan blowing up towards it, and take it from there.
 
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ratbuddy

ratbuddy

Member
Joined
Aug 24, 2007
Ick.. pushpins..... leave it alone in that case. Those never go back on the same. :(

Yeah, I've noticed that too. They are spring loaded though, and have maybe 1/4" travel, so if I get really ambitious I could raise the heatsink and q-tip the paste out, then spatula some new stuff under there without having to remove the pins. I don't have any crashes or other issues though, so I'll just add the fan I mentioned and maybe undervolt PCH a little to see if I can get into the 60C range. If so, I'm fine with that.
 

dfonda

Senior Golfer
Joined
Feb 25, 2004
Nice,,, you got it done faster than I did with my FTW3...I still have a hybrid to put on my 3080 XC3...Not looking forward to it....Am looking forward to the results, the hybrids do the job...

No rad police checked in yet to tell you the rad is upside down yet?:p
 

EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
No rad police checked in yet to tell you the rad is upside down yet?
Glad they didn't. There's nothing wrong with that config. The top rad has the out/in facing down, and the vertical rad has them on the bottom (I assume as they are not up top, lol).
 

dfonda

Senior Golfer
Joined
Feb 25, 2004
Glad they didn't. There's nothing wrong with that config. The top rad has the out/in facing down, and the vertical rad has them on the bottom (I assume as they are not up top, lol).
I don't care about it either but I see the front rad from the GPU with the inlets at top same as mine. What am I missing? Last pic in OP.

EDIT: No my bad , I see the hoses go to the top Rad...:unsure::giggle:
 
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EarthDog

Gulper Nozzle Co-Owner
Joined
Dec 15, 2008
Location
Buckeyes!
I don't care about it either but I see the front rad from the GPU with the inlets at top same as mine. What am I missing?
They aren't up top. That's the top rad's in/out. One of those M.C Escher images, lol. You can also see the 'nub' of ports on the bottom of the front rad. :)

Look up a few (several) pics... there's another shot of the rad and you can see ports at the bottom a bit more clearly.

5WHcT7c.jpg