4 core 5 GHz, Is it possible to keep the boost clock as a normal clock if thermal and power are enough like Intel? what is preventing the clock to keep standing? I turned off one CCD on my 5950x and the maximum power consumption is 117w for the 8 cores and thermal is acceptable 73c which is fine.

1 : Anonymous2021/06/20 14:08 ID: o46gu1
4 core 5 GHz, Is it possible to keep the boost clock as a normal clock if thermal and power are enough like Intel? what is preventing the clock to keep standing? I turned off one CCD on my 5950x and the maximum power consumption is 117w for the 8 cores and thermal is acceptable 73c which is fine.
2 : Anonymous2021/06/20 16:08 ID: h2fv1bw

Even if you are below the wattage, amperage, and temperature limit in PBO, at some point the cpu determines that it cannot push anymore voltage to increase the core freq because it will damage itself. Obviously this is different for every cpu because silicon quality varies.

Lowering temps can help a small amount because it lowers leakage and makes the chip more stable. For example, having your cpu and case fans at maximum speed will yield a slightly higher sustained boost freq than having them at 50%.

ID: h2gk0m5

Yeah, you really got drop the temp a lot if you want the chip boost logic to do all the work safely. Chilled water, AC intake/exhaust loop, or TEC can do it.

ID: h2fvupn

"at some point the cpu determines that it cannot push anymore voltage to increase the core freq" its 5950x with half of the cores, I'm pretty sure it can handle to push more voltage since my current MB can push 160w easily, so why just drop to 103w instead of 160w? I wonder if it's due to the MB or some other factor that drops all 8 core to 4.6 instead of 5 or 4.9.
Or by looking at the graph again, I can see the slowest core (7th) is 4.675, maybe all core high boost determined by the slowest core?

ID: h2g0wbu

The processor has a FIT limit that prevents it from consuming endless power and voltage. That limit changes based on:

Temperatures (each core, SoC, L3 caches etc. all have temperature sensors). There’s also a ‘mid throttling point’ where boosts and voltages back off slowly past a certain temperature. Iirc this is 70 degrees (for Zen 2, may be different for Zen 3).

Which core(s) are being used (the quality of each core differs hence it can use different voltages for a given frequency and hit FIT limits sooner or later than other cores)

Current/voltage limits which are denoted by TDC/EDC and DVT

Windows tools don’t show that FIT limit but you can view them on Linux. Use that tool and experiment, I’m gonna bet that you’re hitting FIT limits preventing it from boosting higher and consuming more power.

For example with my 3700X, 2 of my cores hit an 80+% FIT limit running a single core workload while the rest would do 20-30% and the worst hits 100%. Under an all core workload without PBO, the overall FIT limit is ~6% (88 W PPT limit by default which it consumes immediately hence it power throttles) but with PBO, it reaches 100% (@ 142 W PPT limit, sustained power consumption at ~100-108 W).

FIT is what denotes what voltage and power as well as clock speeds the processor will use under sustained workloads, even if you raise power limits to 500 W or so — the processor won’t consume an endless amount of FIT determines it will damage itself.

ID: h2fw896

Your cpu with 16 cores can pull 160w, sure. That doesn't mean that 8 cores will also be able to pull 160w. Wattage is a function of voltage*amps. In order to pull more wattage, it would have to run at a higher voltage which the cpu has determined is unsafe for 8 cores.

ID: h2g5po8

Please set your voltage to like 1.8v manually in BIOS and leave us alone

3 : Anonymous2021/06/20 16:43 ID: h2fze6f

No, it's boosting to 5ghz on only 1 core at a time, and only for brief periods. You are just looking at the max.

If you were to set all cores to 5.0 it would crash. Even if somehow you could just set those 4 cores to 5.0 (maybe there's a way but I don't think so) it would probably still crash.

Just leave it, there's very little to gain from manually OC Ryzen cpu, they already do a good job on their own (assuming PBO). Most of the time you'll actually lose single threaded performance, because you'll maybe get 4.7 max all core, but with PBO one core will boost to 5+ when needed

ID: h2gbv52

I mean he could probably lock them all to 5Ghz and yeet the voltage, but the chip wouldn't last very long!

ID: h2g0jf6

You are not wrong, each core boost to that clock individually, but all can do 4.6
What I'm trying to find is, why they can't all do 4.7 if there is thermal room and enough power? Intel platform does that from the MB option boost setting. if you are below the threshold then intel CPU will stay in the boost clock.

ID: h2g55fr

I mean you can try all 4.6 or so but you're actually losing single core performance because it can't boost to 5.0

4 : Anonymous2021/06/20 17:33 ID: h2g5go5

CPU controls voltage and boost of each core individually. Some of them can boost within spec voltage, some cannot. Some of them might not reach 5 GHz ever, except on LN2. The more cores the greater the variance in capabilities, so on 16 cores you probably get several golden cores, and several crap ones. All-core OC is limited by crap cores, PBO is not. Intel behaves quite the same rn, used to be different: it could not control boost as precisely and therefore didn't boost to the limits, that's why you had a very high probability to all-core OC to 1-core boost clocks, if thermals and power is not a concern.

ID: h2g6ynb

You are correct, I said in one of my comments that I think it's due to my crappy core "core 7" which is the only core limited to 4.675 if you look at the graph and I get downvoted to hell.

5 : Anonymous2021/06/20 14:13 ID: h2fhw1i

A small fix to the title, thermal is 79c using air cooler Noctua nh-d15s which has only one fan, and my room temp is hot 25c so thermal is not going to be an issue for 8 cores for 117w CPU.

Btw my MB is MSI b550 tomahawk.

And the CTR gave my CPU a bronze sample tag, since it can't handle OC or lowering the voltage with 16 cores.

If I remember correctly, you can keep your boost clock on an intel platform. I wonder if this is possible with AMD CPU.

I believe Precision Boost 2 boosts the CPU as much as possible within the power limits that can be changed via PBO, but 117w is not the current limit of mine, neither 79c temp, so what's preventing the CPU to keep the high clock here?

ID: h2fu9vr

79 is the average temp.

Temp is likely higher in some areas of the core.

ID: h2fw1gd

CPU has only one temp sensor on each core, so even if the part of the core is higher than the sensor, how would the CPU know its higher and downclock itself if the sensor is tell the CPU its fine? I don't think the temp is currently the limit factor here.

6 : Anonymous2021/06/20 22:54 ID: h2h7k4j

For me CTR is the best working(and fastest, least painful) option, when it comes to overclocking. Use the 2.1 version, that's the best for 5000 series Ryzen. Even if your CPU is a bronze sample, you can still adjust it and get a decent performance uplift on allcore and still have the original single core performance with CTR's Hybrid O.C.

ID: h2h8kcf

Thank for the suggestion, I was trying to find the best setting to boost half the core for gaming. and it looks like the temp is the main issue to solve. 70c is high.

7 : Anonymous2021/06/20 20:55 ID: h2gty2f

S.a . Meet m..0. No no puppy I'm .. Mom......7 ...

引用元:https://www.reddit.com/r/Amd/comments/o46gu1/4_core_5_ghz_is_it_possible_to_keep_the_boost/

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