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sdugoten
Journeyman III

Ryzen 3950x with low Cinebench R20 score

I have set the 3950x on stock speed with no PBO nor auto overclocking running on ASrock x570 Creator with Corsair H115i Plat cooler. The highest temp I got when running R20 is around 77 degrees and idle at 47 degree. I live in a related warm country so the temp seems OK. However, my R20 score is just around 9008, which seems a bit slow compare to other people have around 9300 using the same CPU without PBO.

I guess the problem is that the CPU boosting speed even on single core never really hit the advertised range. The highest speed I got on a single core is 4331Mhz, which is far from 4700mhz.

I wonder where is the problem which make my 3950x that is 300 points of score lower than other 3950x? Thanks.

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2 Replies

Try enabling PBO in the BIOS as this will allow your CPU to boost properly.  

Andy

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psikotic
Journeyman III

The motherboard and bios revision (agesa version more specifically) Precision Boost 2, will clock your cpu (resulting in higher scores in R20), the stepping is almost always limited by temperature. Precision boost overclocking (PBO) is not to be confused with precision boost,

* They are two completely different things with a poor naming convention. PBO is not short hand for precision boost.*

Precision booster *Overdrive* will simply lessen (or remove) the power restrictions on the cpu, which rarely if ever is needed in my experience. (no gains on agesa 1.0.0.4b) also voids your warranty.

I run an x570 aorus xtreme board, with the latest (agesa 1.0.0.4b as of Feb 8th 2020) I get around 9200-9300 'ish' on R20 with multicore test. I'm using a 360 AIO with 100% pump and fan speeds. Running temps are about mid 70's for the test (under sustained loads I'm around 82-83c with around a 24c ambient temp) 

Best benchmarks as of  time of this post and agesa bios release 1.0.0.4b being the latest microcode update/bios release, the best results I've got were on agesa 1.0.0.3 abba bios revision.

For highest benchmarks in my experience do the following.

Bios revision for your mainboard with the 1.0.0.3 ABBA Agesa.

With PBO on, all power limits removed with +200 mhz (auto over clock)

(which is yet another feature, but found in the PBO menu.. but not precision boost, or PBO, (it's auto oc) which is used in conjunction with PBO, but not part of PBO itself,  yet found in it's menu. ack with naming conventions AMD) 

Also disable and close all RGB software (and related bloatware services, Asus being the largest offender, followed by corsair and gigabyte bloat ware for RGB in second place tie)

Max out your fans/pump speeds.

Precision boost 2 will ramp up the clock based off of 3 things, but the important one is temprature. Where you 'might be good' with a single threaded task running a 58c temp, and lower fan/pump speeds, you will boost higher (and consequently higher scores with cooler temperatures.)

This will get you the highest score I've found so far, However even with my 360 AiO water cooler at max fan/pump speeds on agesa 1.0.0.3 ABBA with these settings  the heat is absolutely insane. Using all core load (folding @home in my case) the case temps levelled off at 94c with max pump speed and fans, with a 23c ambient. 

Being as this was not acceptable 24/7 temps I ended up eventually going with the latest (1.0.0.4b agesa) with everything left on AUTO. enable your XMP profile (if applicible). Set your core voltage to manual, (leave it at default) then throw in a negative voltage offset by -0.1v.

This (with rgb bloat ware etc not running) gives me around a 9100-9200 R20 score with max pump/fan speed on a 360 closed water loop. Based on ambient temperature, and pause time between runs.

All core load with the 'safer' setup using folding @home (100% all core load) equalizes to  81-83c (depending on ambient) which was still hot, but far more acceptable. 

Tldr; Get a cooler.. get alot of cooling and then more cooling. TDP is a joke and this is no exception. 240mm aio is suggested, I'm using a 360 at 100% and struggling to keep it under 90c on all core load.. it runs hot, and the cooler you can keep it, the higher those clocks are. The undervoltage -0.1v offset not only lowers thermals, but the lower thermals allow precision boost 2 (enabled by auto/default) to boost higher with the additional thermal headroom provided.