Razer Core X mod [Corsair SF750, Noctua 120] + MSI 3090 SuprimX
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Razer Core X mod [Corsair SF750, Noctua 120] + MSI 3090 SuprimX  


Active Member
Joined: 4 years ago

TL; DR: The GPU fits....barely!

Hi folks,

Wanted to share my recent mod of a Razer Core X. I wanted to swap the stock PSU to a more silent option but also because I needed 3 8 pin PCIe cable to power the beastly MSI 3090 SuprimX. Also I didn’t want to use the stock big and loud PSU as that produced a lot of heat and noise and didn’t want to just swap the internal fan of the PSU and resort to soldering the new fan to the TB PCB. Wanted to do something that can be reverted easily to stock but didn’t end up quite as planned 😂 


Anyway, on with the build!


First I took out the stock case fan and removed the PSU! Without watching any tutorial, I stupidly struggled to get out the PSU, even after removing the case fan holder and the two screws for the bracket, but after wiggling it around for a bit I managed to get it out.

I then unboxed my new sff Corsair SF750 PSU and being my first ever experience with a sff psu, I thought the stock one was a small form factor psu, as most of the time I have dealt only with big full size PSUes like Corsair 1600axi or the big EVGA 1600 supernova P2, so I was shocked actually about how small the corsair psu actually is and then quickly I saw a problem! Being smaller in all 3 dimensions, the top bracket that held in place the old bigger PSU, can no longer be used. Also the outer plastic cover of the power connector is bigger than the stock PSU, as in it is both wider and also protrudes out more than the stock one! After fiddling for like 30 minutes thinking of ways to secure it in place and also to make the power connector fit the hole of the case. I had two scenarios in mind: either use the bracket and thus lift up much higher the power connector which would result in me needing to cut open the back side of the core X to make room for the power plug to fit the power connector, or use the stock one by filing away the lower part and make somehow due without the bracket. I thought the second approach was better with less impact on the esthetics as it would not leave behind an empty space with the old power cut-out. But there goes my whole plan to keep it “reversible”.

I used at first a heavy duty file that made quick work of the layers of what I suspect is aluminum. However I used a rather soft touch to chip away just enough to make it a snug fit for the plastic parts of the PSU. After getting close enough to almost made it stick, I used lower grit files to try to smooth out the edges. After decided of the final form, I then used a ghetto approach and use part of some leftover package foam that I had to cut a piece thick enough that it would support the psu and just thin enough that would allow me to pressure it underneath the PSU without having it raise too much so that it may take it out of the newly created holder. Here are the pics:

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I routed the cables as best as I could leaving a U shaped excess of the 24 pin cable in tension and away form the unit fan. That way I thought, the tension would help with keeping the PSU towards the back end of the case. I added the 120mm Noctua PWM fan and kept the push in air config, thinking the 3090 needed it for the back PCB which hosts also the very hot GDDR6X memory modules.

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Installed the gigantic 3090 Suprim X and said oh-oh...it’s actually significant longer than the eGPU “tray”.

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After this, with some real feeling of potential disappointment, I tried to see if it fits! The result? Barely! It leaves just play room for the latch to close the case and secure it although it puts a little bit of pressure on it since the tray “door” is left a bit crooked. 😂 

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Moment of truth was doing a test run! I connected it to my 16” 2020 fully specced MBP, in Bootcamp, and at first it put out a Code12, but I tried to the other side of the TB3 connections and it worked. Maybe it interfered with another TB3 connection coming from the Plugable TB3 docking station on the same side (right). 

Test ran it, and I saw that the central fan of the 3 fan design, would not spin at all. I quickly shut it down and I saw that there was some pressure on the center mesh of the Razer Core X, probably from the GPU itself which is quite thick or the slight pressure of the latching mechanism from the back...or both. Anyway, using ogrish fisting 😂 I forced the mesh to bulge out a bit in the center part where the central fan would position itself. I used at first moderate force thinking it might brake the edges of the mesh but to my surprise it felt sturdily anchored, so I used even more force to make room for what must be a less than 0,5 cm offset for the center fan. It is barely noticeable when looked upon from the top and not noticeable at all looking at it from the side.

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Because I had to take out the tray for the above procedure, I had to unplug the power cord that was initially carefully plugged in, and when I reconnected it I used a tiny bit too much force to make the PSU drop from the metallic place holder and go like 1-2 cm inside the case! Ooops! 🤷🏻‍♂️ It turns out that it doesn’t sit that secure and in fact it’s quite fragile as almost any force would make the foam underneath slide away inside along with the PSU. 😆🤦🏻But if any of you have any ideas or experience with securing this form factor PSU to the razer core X then I’m all ears!


So all in all, this long post was not about how I didn’t pretty much preplan anything, nor about my ghetto solutions, but about the fact that the SuprimX 3090 fits in the Razer Core X. That’s the tl; dr I guess... I am pretty pleased with it, and the GPU, and in full load it is quieter than my Gigabyte 3090 Aorus Gaming Box (which is water cooled- not that it matters). In fact it’s a good 10db quieter, averaging around 52db at 10 cm from the fans. Memory junction temps are acceptable sitting usually between 90 to 100 C in memory hard applications under full load. The backplate on the thing and/or thermal pads are significantly better designed than the 3090 FE cards. Maybe it helps because the fan is in push configuration bringing fresh cold air inside the case, in the back of the card, whereas the 3090 FE would exhaust hot air where the case fan would push fresh air in...and I assume in that case it would be better to reverse the fan to exhaust.


Anyway! Enough about all this! Hope someone finds this useful! 


Cheers and excuse the potential grammar mistakes or typos. English is not my native language!





To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.


itsage liked
Founder Admin
Joined: 6 years ago

@andreid2017, Thank you for sharing this PSU swap and your adventure of getting all components to work. Sometimes a bit of brute force is in order.


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Joined: 1 year ago

I am thinking to do the same with my MSI 3080 Suprim X.  Was wondering if it the core x chroma will fit.  After reading your post, I wont change the PSU, but thinking to order a Noctua 120.  Not sure which Noctua 120 will work with the core x.  I am also wondering if it helps to cold down the card vs the stock razer crappy fan.

To do: Create my signature with system and expected eGPU configuration information to give context to my posts. I have no builds.