The Secrets of Curve shaper, 9950X Zen 5 Tuning Guide.

[@tenney15]

We got JohnnyRage without a mustache before GTA6

[@JohnnyRage303]

The mustache was in your head, you saw what you wanted to see.

[@kevinerbs2778]

Have you tried to get higher Uclk speeds? You are probably the only person I've seen do the right thing with the 8000mhz ram & higher divider. It was obvious that the 2000mhz Fclk infinity fabric would be a bottleneck for 8000mhz even with the divider. Since bandwidth would override latency.

[@JohnnyRage303]

On my 9600x I have a 6000mhz kit. I oc'd it to 6400 cl 30, and ran uclk 3200. Anything beyond that I couldn't get 1:1. At one point I had it booting with 2400 fclk, and I was like zen 5 is gonna slap. But once I applied all my settings it was never able to boot at 2400 again. Both the 9600 and 9950x have no problem at 2200 for me. I'm 2 out of 2 for immediately setting fclk 2200, where zen 4 it seemed like one in a hundred would hit 2200.

[@kevinerbs2778]

@@JohnnyRage303 is your uclk only 2000mhz on the 9950x? while the infinity fabric is 2200mhz?

[@JohnnyRage303]

Yes, because at 8000MT ram speed you have 4000mhz DDR5, the uclk can either be = memclk or 1/2 memclk (4000mhz in this case) Uclk will not run 1:1 at 4000mhz. the highest I have gotten is 3200mhz on ddr5 6400. so if you are forced memclk/2 you get 2000mhz. now with dual ccd cpus there are 2 seperate infinity fabric lanes one to each ccd. So my initial testing running Fclk faster improved my cinebench scores. All zen 4 and on CPUs have desync'd frequencies, where AM4 you needed to run 1:1:1 or you would take penalty latency. this is not true for zen 4-5. People generally just run 2:3 because this ratio was recommended initially by AMD and it works well 2000 fclk 3000 uclk/memclk 6000mt/s ram. its on my list of things to do benchmark 9950x 2000 flkck, 2200 fclk, and my ddr5 6000 kit to see what does the best.

[@chryseus1331]

There still isn't a really compelling reason to upgrade to Zen 5 for most people with a mid-high end previous generation CPU, the overall performance improvement isn't massive and upgrading is relatively costly going from DDR4 to DDR5, so it isn't too surprising they're struggling to sell them, maybe when the Nvidia 50 series comes out there will be more of a reason to upgrade.

[@JohnnyRage303]

Yeah, I have done a lot of video card testing and for most cases, any CPU in the last few gens are really hard to bottleneck. if you AM4 and have the 5700x3d available there's not really a reason to build new gen. If you have an older am4 with lower ends parts it might be time to full upgrade but the 7000 series is a 95% solution with 70% of the cost. I'm not surprised they haven't sold like crazy but all rumors indicate intel will be in the same spot. All that aside I have had fun learning to tune the new system. Thanks for watching / commenting.

[@kodemdotexe4925]

curve shaper isn't what I thought it would be, seems like a extention of curve optimizer, should be no reason they can't do this for zen 4 or even zen 3

[@kevinerbs2778]

They can't because they calibrated it for the lower temperature sensors of Zen 5.

[@kodemdotexe4925]

@@kevinerbs2778 i don't think that would prevent them from doing so, unless the sensors they are using are wildly different. especially for zen 4, zen 3 maybe but i don't see why they couldn't do this for zen 4.

[@JohnnyRage303]

It's a nice touch because you get squeeze out that extra bit after finding your stable optimizer setting. I doubt they will offer it backwards to zen 4. As mentioned I think there's additional temp sensor info.

[@kodemdotexe4925]

@@JohnnyRage303 if the extra sensor information is whats enabling the curve shaper feature that is interesting at best. but I understand now why curve shaper on the 9600X isn't worth it at all.