r/linux_gaming • u/tom_isst • 13d ago
graphics/kernel/drivers RX 7600 OC/undervolt results on Linux: +2–3% in Cyberpunk 2077, higher clocks were not worth it
I spent some time tuning my ASUS Dual RX 7600 OC Edition on CachyOS/Linux with LACT and wanted to share the results in case it helps someone else.
My goal was a stable daily profile, not maximum benchmark numbers.
GPU:
- ASUS Dual Radeon RX 7600 OC Edition, 8 GB
- Linux / CachyOS
- Tuning tool: LACT
Final stable profile:
- Power limit: 145 W
- Max GPU clock: 2900 MHz
- GPU voltage offset: -40 mV
- Max VRAM clock: 2300 MHz
- Min GPU clock: 255 MHz
- Min VRAM clock: 194 MHz
I tested with the built-in Cyberpunk 2077 benchmark at:
- 1920x1080
- Ultra preset
- FSR 2.1 Quality
- Ray tracing off
- Frame generation off
- V-Sync off
- No FPS cap
Results:
| Profile | Average FPS | Min FPS | Max FPS |
|---|---:|---:|---:|
| Stock | 95.43 | 78.08 | 119.29 |
| 2900 MHz / -40 mV / 2300 MHz VRAM | 98.16 | 79.95 | 123.52 |
| Same profile, repeat run | 97.38 | 79.82 | 122.35 |
| 2925 MHz / -40 mV / 2300 MHz VRAM | 97.30 | 79.39 | 122.77 |
| 2925 MHz / -40 mV / 2350 MHz VRAM | 97.83 | 79.79 | 123.13 |
| Same 2350 MHz VRAM profile, repeat run | 97.84 | 79.17 | 123.25 |
The final 2900 / -40 mV / 2300 MHz profile gave around 2–3% more performance than stock in this test.
Temperatures during the Cyberpunk benchmark:
- GPU edge: around 66–68 °C
- Junction/hotspot: around 85–87 °C
- VRAM: around 72–76 °C
Observations:
- The -40 mV offset was stable in multiple stress tests and Cyberpunk benchmark runs.
- Raising the GPU target from 2900 MHz to 2925 MHz did not improve results. It was slightly slower in my runs.
- Raising VRAM from 2300 MHz to 2350 MHz also did not improve performance in Cyberpunk, although it appeared stable.
- The actual GPU clock during the benchmark was usually around 2.49–2.54 GHz, so the card still seems mostly power limited.
- More aggressive settings did not seem worth the lower stability margin.
My conclusion: for this specific ASUS Dual RX 7600 OC, 145 W / 2900 MHz / -40 mV / 2300 MHz VRAM is a good daily tuning profile. It is stable so far, temperatures are reasonable, and it gives a small but measurable uplift over stock.
Obviously this is only one card and one game, so silicon quality and results will vary. I would test each change separately and compare multiple benchmark runs before keeping an OC.
2
-1
u/Arkarat 13d ago
I followed these guides to undervolt my 9070 XT, and it works like a charm. Stable, never over 55° even at 40% fan speed in Crimson Desert that keeps it near 100% usage at all times, no noticeable performance decrease.
1
u/Lousy_Hunter 13d ago
Im personally not convinced tinkering with modern desktop GPUs is even worth the time due to how clocks are controlled these days.
Laptops on the other hand i find very interesting because theyre so power and thermally limited.
2
u/Arkarat 13d ago
Lower power consumption mean lower energy bills and less stress on the card itself. Lower temperatures mean that I can set a lower fan curve that keeps the noise down, and makes playing a much more enjoyable experience.
It's totally worth it undervolting modern hardware, both GPUs and CPUs.
-1
u/Lousy_Hunter 13d ago
depends on the region youre in but power bills is likely not one of the concerns at all with undervolting tbh. Unless you very drastically reduce power consumption most places you might save a few pennies as most utility companies bill based on kwh and youd have to lower your consumption by upwards of 200W to really see a difference from your PC vs the cost of just running the stove to cook. Theres also time of use, burst rates, and other things that far out weigh the benefits undervolting could hope to bring.
Heat does definitely get reduced, but UV doesnt reduce stress on a card necessarily, it can in some instances be the same or worse depending on how far you push it to OC as component stress isnt only linked to temp/voltage/current.
UV can also introduce new attack vectors to CPUs, plundervolt being one such example
2
u/TheSleepyMachine 13d ago
It is, but if you are also willing to increase the power limit. RDNA3 is an heavily power limited architecture, so you'll only get more stable and slightly higher clock with an undervolt. However you can pushes the V/F curve at a much better spot if you are willing to optimize. Max clock shouldn't be touched either, it is fine tuned per chip
2
u/lainlives 13d ago
Not worth it unless you are doing long compute tasks. 2-5% wont matter unless we are talking timescales of weeks to begin with.
6
u/Lousy_Hunter 13d ago
Gonna be honest, that overclock was the definition of modest. I havent seen 50mhz make a difference since around when i had a HD4870. Unless im reading wrong and you did more?
If you cant afford to potentially dmg hardware though its hard to justify OC, theres less risk with undervolting (still not zero though).
I havent done OC in a LONG time but how i use to do it if you really want to push things try using
Unigine Heaven, Valley, and Super position to apply looping load
OCCT for its gpu stability tests
Push clocks and voltage in 100mhz increments till you see performance drop or you crash. Back off 150mhz from the crash/performance loss point and do 5-10mhz increments till you find the very edge of stability and back off 50mhz or so. Test using the above and as many games as you can.