Nuts and Volts

Bad ASIC Quality ≠ Potato Core| GTX 770 Lightning | Part 1: Voltage Control

Yep that's right, more Kepler baby! In all seriousness though Kepler is a joy to overclock at ambient for me. Easy voltage scaling, good selection of cards, tons of tweaks and tricks, and SLI if you want to go down that route.

In this case there was a GTX 770 Lightning for sale on FB marketplace with the OG box and accessories. Not owning a Lightning and wanting to have a second 770 to compare against and torture. Haggled the price down from 100 NZD to 85 plus shipping. Arriving packaged well, the box was in near mint condition.

After cleaning the card and giving a healthy amount of thermal paste I went straight to GPU-Z to make backups of both the LN2 and Normal BIOS's. Checking the ASIC showed that it was only better than "%30 of GPUs on Techpowerup database". Testing the card at stock voltage would seem to agree with that statement. However I have a "secret" tool, more voltage. Giving a quick test of EVGAs Classified tool not seeming to have any effect on voltage I swapped to drastic measures.

Not finding a download link for afterburner extreme within the first page of google, I decided to try GALAXs HOF software for the 780 Ti since they not only share the same voltage controller for Vcore, but also Vmem (up1612Q). After getting a copy from StrunkenCap and firing up the non BIOS checked version, raising Vcore to 1.25v and checking with a DMM it works! Memory also works, however the 20mV steps are a little inaccurate to what the real voltage is; make sure to check. Load line also works however I haven't attached the scope to see which is the best setting.

Speaking of the scope, the GPU reactor on the back of the core. That's a thing which exists, begging to be modded. Part 2 or 3 will probably include upgrading the GPU reactor with a metric butt-ton of caps.

I was expecting pretty bad temps given the heatsink quality however I was pleasantly surprised that it didn't surpass 60c running Firestrike at 1.4v (Ambient of 15c)

Not finding a download link for afterburner extreme within the first page of google, I decide to try GALAXs HOF software for the 780 Ti since they not only share the same voltage controller for Vcore, but also Vmem (up1612Q). After getting a copy from StrunkenCap and firing up the non BIOS checked version, raising Vcore to 1.25v and checking with a DMM it works! Memory also works, however the 20mV steps are a little inaccurate to what the real voltage is; make sure to check. Load line also works however I haven't attached the scope to see which is the best setting.

Speaking of the scope, the GPU reactor on the back of the core. That's a thing which exists, begging to be modded. Part 2 or 3 will probably include upgrading the GPU reactor with a metric butt-ton of caps.

I was expecting pretty bad temps given the heatsink quality however I was pleasantly surprised that it didn't surpass 60c running Firestrike at 1.4v (Ambient of 15c)
The fans and shroud I can't say as much though. Who ever designed the way the fans attach to the heatsink I despise. You are gargantuan to end up damaging the finstack and scratching the heatpipes in a valiant attempt to remove them. Some small other details the card has are blue LEDs behind each phase for Vcore and Vmem along with one on each of the fans. 

Final lazy testing results ended up with the core running at 1424 MHz 1.4v (Voltage read points from the card) and 2000 MHz on the mem at stock voltage. Memory chips are Samsung and increasing voltage from 1.6v to 1.7v did reduce artifacting at higher clock speeds however didn't fully go away. The core still isn't as good as my GTX 770 Classified and certainly not as good as the memory on that card. I would personally say the core is pretty average, maybe a little above. Memory however is mid at best.

Firestrike results below.

Next part is probably running with a waterblock attached, extra controls such as switching frequency, scope measurements, and maybe the GPU reactor.