How to remove Fermi and Kepler laser cuts to fully enable core. 680m success

Discussion in 'Hardware Components and Aftermarket Upgrades' started by Khenglish, Jul 24, 2020.

  1. Khenglish

    Khenglish Notebook Deity

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    @TheQuentincc

    For 28nm clock scaling beyond 1.1V is poor. My understanding is desktop stock volt Kepler cards tend to top out in the 1200s so 1350 at stock volts is excellent.

    Mixing memory speed grades is fine. When switching memory chips on a card I do 2-4 at a time, then test the card. Doing all 16 and then having an issue is not fun.

    Mixing memory brand is bad. Hynix and Samsung memory timings are highly incompatible and require major downclocking to work at all.

    Mixing dies from the same manufacturer is questionable. I switched out 7GHz Samsung C dies for 8GHz E dies and lost clocks on a 980m board. I suspect the C timing table was not very friendly to the E die, but maybe the IMC needs to be designed for it, like Haswell designed DDR3 not clocking well on SB and IVB systems even when overvolted.
     
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  2. TheQuentincc

    TheQuentincc Notebook Evangelist

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    First generation of kepler seems to top out at 1250~1300 while the "second" generation goes to 1300~1350, out of 4 7xx kepler cards, I got at least 1300MHz at stock volt.
    Yes you can get a very different timings between memory die, for exemple on ddr3 there is elpida hyper vs hynix mfr, one maxes out at 2000~2200 cas 6 while the other is more 2800+ cas 8 on air, to know which timings is used between die revision, look at amd bios, they list the timings, which shouldn't be so far off nvidia timings.
     
  3. Khenglish

    Khenglish Notebook Deity

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    Yeah the 700 series does seem to clock a little higher than the 600 series. The 770 is gk104-425, instead of gk104-400, so maybe there was a mild die revision for higher clocks. Looking up 780m and 880m overclocking they do seem a bit better than 680m clocks on average. Now I am slightly inclined to replace the GPU core... I do have a substantially better than average first gen core though. I have seen 680m overclocking at stock voltage between 902 and 993 MHz. Mine was probably good for 980 prior to shader unlock. I never tested max overclock prior to unlock, but I would think more active core dropped it a 13 MHz bin. Not much more to be had by a 2nd gen core. More gains for less work to replace memory. Core is such a PITA to swap.
     
  4. TheQuentincc

    TheQuentincc Notebook Evangelist

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    The hardest part for me when it come to swaping core is to reball the new chip...
     
  5. Khenglish

    Khenglish Notebook Deity

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    Yeah that's annoying as hell. You'll get all but say 5 balls. Redo those 5 and have 2 left, then 1 left, then still 1 left... I got a fairly good method at this point so that reball only take me around half an hour to an hour. The biggest issue I have is random corners deciding not to settle properly leaving opens.
     
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  6. Mr. Fox

    Mr. Fox BGA Filth-Hating Elitist

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    I just stumbled upon this thread by accident. Awesome work, as usual, Brother @Khenglish.
     
  7. Ionising_Radiation

    Ionising_Radiation ?v = ve*ln(m0/m1)

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    Absolutely incredible work, @Khenglish. I love this community (despite the sometimes overly hard anti-BGA sentiment here) because of how hard everyone here pushes their notebooks even if they're massively neutered, and this makes me want to push my 80 W RTX 5000 as much as I can.

    Sucks to have a core count equal to the RTX 2080 Super, but have it perform like a RTX 2060...
     
  8. Khenglish

    Khenglish Notebook Deity

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    You can always shunt mod it. You just need a soldering iron and you can order the shunts off mouser or digikey.
     
  9. Ionising_Radiation

    Ionising_Radiation ?v = ve*ln(m0/m1)

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    Yep, I've got shunt resistors arriving later this month. Hopefully I have a steady hand.
     
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  10. Vasudev

    Vasudev Notebook Nobel Laureate

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    I'm usually lack finesse in this mod and I doubt if it can be applied to maxwell 2 980M BGA. My ASIC quality is 58% and OC's are pretty bad.
    Nonetheless, as usual khenglish brings back performance crown from maxwell to Kepler.
     
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