Originally Posted by PsyenceFiction
i have question about powering components of reference gtx780 pcb (VRM, mosfet etc) - these are designed to deliver max 250W arent these? So with unlocked PT by skynet's bioses 340W - shouldn't have it kiled it? its too high current for the powering components or not? what about 440W or 500W unlocked bios! that's crazy isnt it? how can you guys still be using it? what about longevity of the card? Is there any assurance that reference design pcb can handle 440-500W load? I would fear the currenf/power rather than VRM temps...
I would be very glad to hear that my concerns are pointless because i would like to OC more which needs power, but what is the truth? Isn't pumping too much power through powering components too GPU rather killing them than temperatures?
Warning: Spoiler! (Click to show)
And the second question - i decided to replace thermal paste on my reference card with noctua nt-h1 - the results were worse than with default factory TIM, so i put arctic MX-2 on it and it is a bit better than noctua nt-h1 but still worse than default....what could be wrong? i didnt put to much thick layer on the gpu i think...i can post photos how i did it...but im very surprised that i was expecting better temps witch reference cooler and the effect is absolutely reversed...im getting highrt temps than before...
Here is some quotes from my posts:
"Unfortunately no air cooler has good contact with VRM area (power inductors, capacitors and mosfets) and the higher the TDP the higher the amperage which leads to higher power dissipation in the VRM´s and thus higher heat, your card outputs at stock a max (+- )130W TDP thats why you see even at 1,3v lower temps at the core and VRM´s! Titans with 1,3v+ can use more than 400W!
The reference VRM´s can withstand voltages above stock without a sweat, the titans mosfets are rated at high current handling DC-DC 60A with an efficiency of 93%, max temps 125C*, power inductors max ref temps 110C, Capacitors rated 105C!
This (and using waterblocks such as EK that cover the entire VRM area) is why we haven't seen blown up Titans!thumb.gif
But... Dont think that because the components are not bad, it means everything is ok! if you keep upping the voltage there will be a time when the heat transfer will not be enough due to the VRM area heat output and a heat spike will blow the mosfets or the capacitors!
*not exactely 125C , think of it more at 110C due to other factors!"
"6 Phase VRM´s (CORE) 60A each = 360A
DC-DC = I(A) × V(V) = P(W) =» 360A x 1.6v = 576W Theoretical MAX Wattage for the core
Plus 2 Phases for the memory and the rest of the card!
@ 1.40v = 504W
@ 1.45v = 522W "
"Did some testings today and this is for all those inquisitive minds out there wandering on the power draw of our beast cards running GK110!
Bear in mind that my system is in my SIG and the only difference was the [email protected]
@1,30v! Using triple monitor 3240 x [email protected]
SLI TITANS W/ Skyn3t Rev2 bios
and memory at stock 6000mhz!
1306mhz / 1,37v / power draw 124% / load 99% 372W*
1333mhz / 1.37v / power draw 134% / load 99% 402W*
1359mhz / 1.37v / power draw 139% / load 99% 417W*
1385mhz / 1.37v / power draw 145% / load 99% 435W*
1400mhz / 1.39v / power draw 155% / load 99% 465W*
*Power draw just for one card
As you can see voltage alone will not increase power draw until you increase clocks and dynamically load your card, power was being drawn from the wall ranging from 850W - 1250W!"
I hope i made your mind at ease but if not feel free to PM me with more questions!
More bed time reading! Warning: Spoiler! (Click to show)
"Please do NOT GO ABOVE 1,212v WITH SOFT VOLT MOD AND LLC DISABLE!
No air cooler has the capacity to dissipate the heat load out of the VRM area when OC with overvoltage! And you cannot know the VRM´s temps, only do an estimate calculation based on your power draw! HEAT KILLS!
Exactly what happens depends on how excess the power is. It may be a sustained cooking. In this case, the MOSFET gets hot enough to literally unsolder itself. Much of the MOSFET heating at high currents is in the leads - which can quite easily unsolder themselves without the MOSFET failing! If the heat is generated in the chip, then it will get hot - but its maximum temperature is usually not silicon-restricted, but restricted by the fabrication. The silicon chip is bonded to the substrate by soft solder and it is quite easy to melt this and have it ooze between the epoxy and the metal of the body, forming solder droplets! Excess heat leads to short circuit! Usually, a MOSFET will fail short first. This is because excessive heat will, by diffusion, mix the dopants enough to create a good conductor instead of the p-n or n-p barriers that were there originally. Often, the gate oxide will be taken into the diffusion, too, causing a short between all three terminals.
Only if the short circuit current after this first mode of failure is high enough to blow the bond wires or the entire transistor, there is an open circuit.
Another forgotten thing is the voltage controller NCP4206 itself! its rated for a maximum operating temperature of 85C and again no way to measure the temperature!
Please guys PLAY SAFE!
ON AIR MAX VOLTAGE: 1.212v + 0.025 (+-) 0.006v = 1.24v(+-)
Keep the fan high and dont let temps go over 70/75C and even this is with a pinch of salt!
And Power Draw debunked: