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crazyjediman24
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Re: Have $200, Will Upgrade

Mon Oct 22, 2018 12:28 pm

DPete27 wrote:
Not to gloat, but I did a pretty in-depth explanation of Polaris undervolting in this thread. That should get you started.
Since that initial article, I've become a fan of AMD's "Chill" feature. Game support has largely been solved, and it's another step toward only using the GPU power you need. My monitor's 48-144Hz FreeSync range certainly allows Chill to do its thing without me noticing, but may not be as fantastic on monitors with tighter ranges (ie 40-75Hz)


Not gloating at all! I may be attempting to memorize that guide as we, uh, type.

I myself am gaming at 60hz, so I might try to just set the framerate control to that and see how bad the fans get. Chill seems interesting, may have to muck with that as well.

I love PC gaming; the experimentation is half the fun!
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DPete27
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Re: Have $200, Will Upgrade

Mon Oct 22, 2018 12:33 pm

My bad, I confused this thread with another and thought you had a FreeSync monitor. In that case, Chill won't be something you need to bother with (Chill clocks the GPU back and reduces frame rates in times of little/no on-screen movement) , but FRTC is good to do so your GPU isn't cranking out frames your monitor will never show. Also look for the option where you can enable "AMD Adaptive Sync" in global settings.

A 50mV undervolt may not seem like much (5%) but it does A LOT to reduce fan noise. My undervolt (-30W at the factory OC frequency of 1305MHz) puts my RX480 on par with the GTX1060 while running full tilt, but add in FRTC and/or Chill and it's even better. AMD did a fantastic job with their power saving features by realizing that not every game/scene requires the GPU to run max/boosted to produce playable frame rates. Heck there's a fair number of less demanding games that my GPU fans don't even spin for.
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synthtel2
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Re: Have $200, Will Upgrade

Mon Oct 22, 2018 1:35 pm

There's a big kink in GloFo 14nm's voltage/frequency curve at 945mV, so my strategy for this is to lock the top clock state at 945mV and adjust frequency from there. On my 480, the limit at 945 is 1190~1200 and I'm actually running 1160 MHz.
 
DPete27
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Re: Have $200, Will Upgrade

Mon Oct 22, 2018 3:11 pm

I would agree with this ^
Despite the move from (stock) 1235MHz to the factory OC of 1305MHz on my card (5.7% frequency increase) it's a 9% jump in voltage. Everything from 1235MHz and down is virtually linear in comparison to that step. My brother's card is a little more leaky on the low end, so his jump from 1235MHz/960mV to 1305MHz/1030mV is more linear than mine.

I've got a couple voltage profiles saved in WattMan. One at the factory 1305Mhz, and the other just has States 6 and 7 at the stock 1235Mhz the RX480 was made for. I only use the 1305Mhz profile in games that need all the GPU I can throw at it (1440p monitor). For the others its a simple click away to change the profile.

I know they said Polaris 11 (RX580) had some efficiency improvements due to process node maturity, but I wouldn't be surprised to see the voltage kink in roughly the same spot on the RX580 (somewhere around 945mV and ~1250MHz)
Main: i5-3570K, ASRock Z77 Pro4-M, MSI RX480 8G, 500GB Crucial BX100, 2 TB Samsung EcoGreen F4, 16GB 1600MHz G.Skill @1.25V, EVGA 550-G2, Silverstone PS07B
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synthtel2
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Re: Have $200, Will Upgrade

Mon Oct 22, 2018 4:07 pm

To clarify, I've seen so many GloFo 14nm chips where the knee is 935-955mV (and never heard of one clearly outside that) that I don't even bother trying anything but 945 anymore for an efficiency-first setup. AMD seems to pad by raising voltages 50mV rather than anything about clocks, so it shows up as 1000mV on curves they create. That applies to Polaris 20 (P11 is the 460) and Vega too, though the slopes on the high side of the knee are probably a bit shallower for those.

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