Overclocking confusion

[Mondas42]

Hiya

 

Fairly new to this site, but Im a little confused. Ive just built myself a new rig after been away from the computing world for a few years, and things have moved on since I last was involved. My rig is a Ryzen 9 3900 X on a Asus ROG x570 Gaming-F Mb. Ive 16Gb of Corsair DDR4 3600 memory. 
 

I’ve been experimenting with some very basic overclocking as I’m still a newbie at this. Anyway I was benchmarking with Cinebench R20 and I got confused. I know that when overclocking you need to keep an eye on cpu temps,  cpu voltages and the clock speed so with that in mind I did three tests. Test one was everything at default on the mb, test two was setting the DOCP to active and setting the memory to its rated 3600 setting, and test three was then activating Precision Boost Overdrive and setting the cpu multiplier to 42.

 

These are my results.

 

Test one - default

cpu speed varies from 3800 to 4200 approx

cpu temp max is 76’C

cpu voltage is approx 1.4V

cinebench R20 result 6802

 

Test two - DOCP on, memory at 3600

cpu speed varies from 3800 to 4200 as above

cpu temp is 71’C max

cpu voltage is approx 1.4V

cinebench result is 6909

 

Test three - DOCP on, PBO on, cpu multiplier 42

cpu speed fixed at 4200

cpu temp is 74’C

cpu voltage is 1.1 V approx

Cinebench result is 7182

 

My question is when overclocking why is the voltage lower and the temp lower than when at default settings?

 

sorry if this is a stupid question but I'm still learning.  
 

Thanks

 

Martin.

[Guest]

The "1.4v" is when idle and meant for single core XFR boosts (the advertised boost clocks).

The 1.1v you see is idling to help keep temps low while transistors are gated (idle/parked cores). That goes up once under a load. This is a result of engaging PBO and multi 42.

At stock the All core boosts are dependent on temps. The single core boosts are good performance. The All core boosts at stock are more power efficient than PBO, your temps will be ultimately higher on average as a result of this feature.  

DOCP is memory overclocking related only. This will not have impact on Cpu frquency.

 

[Mondas42]

8 minutes ago, ShrimpBrime said:

The "1.4v" is when idle and meant for single core XFR boosts (the advertised boost clocks).

The 1.1v you see is idling to help keep temps low while transistors are gated (idle/parked cores). That goes up once under a load. This is a result of engaging PBO and multi 42.

At stock the All core boosts are dependent on temps. The single core boosts are good performance. The All core boosts at stock are more power efficient than PBO, your temps will be ultimately higher on average as a result of this feature.  

DOCP is memory overclocking related only. This will not have impact on Cpu frquency.

 

Thanks for the reply.
 

I think I follow that, that all said, would I be better leaving it at default for the cpu. The increase in performance on the benchmark is marginal and far as I can see my cpu would last longer and be more stable if not overclocked??

[Guest]

Just now, Mondas42 said:

Thanks for the reply.
 

I think I follow that, that all said, would I be better leaving it at default for the cpu. The increase in performance on the benchmark is marginal and far as I can see my cpu would last longer and be more stable if not overclocked??

There's nothing wrong leaving it stock. The processor actually overclocks it's self. That's what the "Boost" is all about. No user intervention needed. Simply set DOCP, get a little more performance and enjoy. You will never beat it on a power efficiency race. I've tried.