Built an MXM(clevo) 3080Ti

[Khenglish]

I converted a Clevo RTX 3060 to be a 3080Ti:

I can't post links because 3dmark blocks viewing scores from unrecognized hardware combinations:



The score is a little bit disappointing. A shunt modded 3080 can beat this (just barely though). I did a 50% shuntmod, but this is giving me OCP throttling and I need to lock the core to 0.84V to avoid it, which is only around 180W. Doing a weaker 10% shuntmod should yield a better result to avoid needing to lock the core voltage.

I'm also having vRAM overclocking issues. The vRAM can only run up to 16.3GHz before the system hard freezes like an NES. With the same vRAM chips the 3060 core could run 17.7GHz. This requires further investigation. I currently have the card set to be 8GB.

I can run more benchmarks if there is something someone is curious in seeing.
 

[Khenglish]

I first tried this on an RTX 3080 board. Unfortunately, the reballing from the seller was faulty and several solder balls detached from the core when soldering to the card, which was visible after removing the core from the card. The core required a reball, but the 3080 pcb died after 2nd core solder cleaning. You can see the power/ground routing got very exposed in the middle. I tried resoldering the core on anyway but it shorted.



This is the 3060 in-progress next to the 3080 prior to removing the 3080Ti core:



As for future mods I do hope to fix the vRAM clocking and finish upgrading the chips for 16GB. Currently only 3/8 chips are 2GB.

In theory a 30 series pcb can take a 40 series core. They are electrically compatible, but my viewpoint is finding a vBIOS that would take that mod is almost certainly impossible. The 3080Ti mod only works with an Eluktronics vBIOS. All other vBIOS fail, including Clevo. Someone briefly listed an MXM clevo 3080Ti for sale on Ebay and Prema somehow identified it as having an Eluktronics vBIOS from the GPU-Z screenshot, which was extremely helpful.

[Meaker]

See the note about memory straps:

 

 

[Khenglish]

Good find on that video.

 

My soldering thoughts:

• Reballing is a PITA. I have found it easiest to use a direct heat minimally sized stencil since they warp much less. I'll also do an initially heating in a toaster oven with the stencil still in place with a very thin flux coating. The slow even heating prevents solder balls from jumping out. After that the solder balls are tacked down and I do a second heat cycle with the heat gun and much more flux to get good connections.
• I also only use leaded solder balls. They are so much easier to work with than unleaded. They bond at much lower temp, are stronger, wet more easily, and pull and center parts more strongly when molten. In general it's worth removing solder from unleaded preballed parts and reballing with leaded. If I had done this I wouldn't have lost the 3080 board.
• His flux seems less corrosive than mine. Mine causes pcb damage while his seemed to cause none. I should use a different flux
• The GPU glue is terrible. The reason why my 3060 pcb is so discolored is because the glue was still sticking after melting the solder to remove the 3060. I had the core under high temp for quite a long time until I got it off. Once the core is off just scrape off the glue with a hot soldering iron. This is way less dangerous to the board than the way he Dremeled it.
• I only use aluminum foil if plastic components are underneath. Components under foil can still get molten, and the slight pressure of the foil can shift them around.

My perf thoughts:

• I also got the weird vram clock toggling. You can fix it by forcing a fixed VF target is MSI afterburner. You can see my scores are around 1K higher than his in TS, and I was just running 0.84V, which I think is sround 180W, similar to his max.
• My core can benchmark at +240, and is fully stable at +210, similar to his
• I'm curious in is vram clocks. Something is wrong with my setup.

 

[jaybee83]

i saw this thread pop up and my very first thought was: oh, that reminds me of @Khenglish and his previous / legendary 980 / 1080 core swaps! then I saw the OP:

 

 

OF COURSE ITS KHENGLISH! 😄 

[Tenoroon]

On 12/15/2024 at 8:54 PM, Khenglish said:

I first tried this on an RTX 3080 board. Unfortunately, the reballing from the seller was faulty and several solder balls detached from the core when soldering to the card, which was visible after removing the core from the card. The core required a reball, but the 3080 pcb died after 2nd core solder cleaning. You can see the power/ground routing got very exposed in the middle. I tried resoldering the core on anyway but it shorted.



This is the 3060 in-progress next to the 3080 prior to removing the 3080Ti core:



As for future mods I do hope to fix the vRAM clocking and finish upgrading the chips for 16GB. Currently only 3/8 chips are 2GB.

In theory a 30 series pcb can take a 40 series core. They are electrically compatible, but my viewpoint is finding a vBIOS that would take that mod is almost certainly impossible. The 3080Ti mod only works with an Eluktronics vBIOS. All other vBIOS fail, including Clevo. Someone briefly listed an MXM clevo 3080Ti for sale on Ebay and Prema somehow identified it as having an Eluktronics vBIOS from the GPU-Z screenshot, which was extremely helpful.

Nice work my brother. Does the PCIe adapter card work with the 30 series GPUs? I would assume so, but I don't think anyone has ever tested it lol.

[Khenglish]

35 minutes ago, Tenoroon said:

Nice work my brother. Does the PCIe adapter card work with the 30 series GPUs? I would assume so, but I don't think anyone has ever tested it lol.

 

It didn't work, but I also tried it in an older desktop. These 30 series cards are really picky and it may have just hated the old Zen+ system. I also tried it in an M2 adapter to a full pci-e slot on a Zen4 system, but it wouldn't even power on. I couldn't fogure out what signal was missing.

 

Also 30 series is rejected by the P150EM. 20 series works though.

[Khenglish]

So I've gotten a bit of improvement:

 

The biggest help was improving the GPU supply voltage on the motherboard. I direct soldered the cable on one end, shortened the cable, and also doubled the motherboard GPU power switch FETs. This efficiency improvement let me increase the GPU voltage from 843mV to 875mV prior to the invisible throttling engaging. This plus added capacitors also let me increase VRAM clocks by 200MHz.

 

 

[Khenglish]

Fixed the VRAM clocking. I had a few incorrect resistor values for one of the added VRAM chips. Now runs 17.6GHz+ like with the 3060 core.



 

Getting close to beating the best 3080 scores. The throttling is hurting me though and it increased a little with the higher VRAM clocks. My core clocks are similar to the best 3080 Ti scores, but they beat me by 800 points.

Maybe these really are HC18 VRAM chips. I'll swap the rest over and find out.

[Khenglish]

So I got a 9900K:

 

 

I'm having lots of issues with it crashing when transitioning from idle to load. If I have it loaded it overclocks well and I can undervolt a lot. Playing around with fixed voltage now to see if I can get it to stop crashing for things like web browsers.

With the 6600K pushing the GPU I almost got 15K. I haven't pushed the GPU with the 9900K yet since I'm trying to figure out the stability issues:

[Khenglish]

This is the best I can do with my current limit issues. 43 points short of the 3080 record. I can't touch the 3080 Ti record due to the BGA systems having much better power delivery:



Things I have learned:

• Classic Throttlestop fixes all low perf at low utilization issues. CPU would improperly downclock, then GPU would downclock even more severely. This even impacted the 6600K. RTX 3060 was fine, but RTX 3080 Ti was not.
  • It's now no longer necessary to force a VF point in Afterburner, so now the card can properly idle without crippling performance
  • Card stability:
    • +195 stable full voltage range
    • +210 stable at < 0.9V
    • +225 stable at <0.8V
      • Card spends most of it's time here under heavy load at default TDP
    • +270 benchable ~0.85V
      • Lots of artifacts, but it chugs along
• ThrottleStop also MOSTLY fixes crash at idle/light load issues if I force high performance.
  • Crashes are a full system lockup
  • C-state control in BIOS and TS does not work, so I don't have a means to fully prevent idle clock drop
  • I will try borrowing another CPU from someone at work
    • This CPU was listed as not working for $60 on ebay
    • System fails to boot 50% of the time
      • This is a bit annoying since I don't have a power button. I need to pull the power cord and replug to reboot
• Interestingly, the ThrottleStop benchmark is a great stability test. It'd give me crashes at higher voltage than anything else
  • TS benchmark stability:
    • 4.2GHz -90mV
    • 4.3GHz -85mV
    • 4.4GHz -85mV
    • 4.5GHz -85mV
    • 4.6GHz -75mV
    • 5.0GHz -55mV
  • I could subtract another 35mV for anything other than the TS benchmark
• CPU or GPU current spikes could trigger a lockup:
  • Limiting CPU clocks helps stability
  • Reducing CPU current limit would cause windows to fail to boot, so I could not attempt this
  • 3D workload on 3080Ti could trigger a lockup if TDP is limit raised, but not if it wasn't
    • Still can get idle lockup
• My plan is to make this a janky SFF desktop, but the occasional idle crashes are a problem for that. The 6600K doesn't crash, but that is a far slower CPU than the 9900K.

 

 

 

[Meaker]

The mobile 3080ti core just can't scale either due to the reduced ROP count for it's size or memory bandwidth compared to the mobile 3080 core at the power levels of the 3080 mobile even shunt modded.

 

A 3080 mobile with the 0.9v voltage limit raised in the 210W range IMO would still make more sense power/performance wise.

[Khenglish]

The 3080 Ti pulls ahead at 160W or so, but it definitely underperforms given how much bigger the core is than the 3080 core. I'm only getting 15K in TS GPU because I'm hitting the card's current limit (not the same as the power limit!), which is an unreported throttle in monitoring tools.

 

Best 3080 score is 15077 at 1986 average core clock:

https://www.3dmark.com/spy/40731969

 

Best 3080 Ti score is 15645 at 1866 average core clock (this is similar to my reported core clocks):

https://www.3dmark.com/spy/32697164

 

I assume both are at 200W. The Ti is only 3.7% faster, which is pretty bad for a 22% bigger core.

 

I considered raising my card's current limit, but since I'm already struggling with GPU power draw with the 9900K I haven't and don't plan to.

[Haku Frey Hellsing]

Wow. i was wondering to get MXM 4070 from alibaba and make it fit to clevo maybe later change die to 4080 or even more if they gonna go cheaper nice idea to that direct power definetly gonna hel since MXM 40 have no power connector. RTX 40 

[SuperMG3]

2 hours ago, Haku Frey Hellsing said:

Wow. i was wondering to get MXM 4070 from alibaba and make it fit to clevo maybe later change die to 4080 or even more if they gonna go cheaper nice idea to that direct power definetly gonna hel since MXM 40 have no power connector. RTX 40 

Hello. You meant from PELADN? They have 0 in stock.