Overclock Question: Core 0 > 1,2,3 ?

[PinkPony 171]

Hi All,

I have happily been running my 4790k at 4.8Ghz for years on Core: 0,1,2,3 (HT OFF).

Extremely stable and < 60C across all four cores during heavy load (P3D v4.4)

I remember reading (can’t find the thread), that some users suggested running Core 0 at 100Mhz more than the rest, as this helps reduces scenery blurries and improves sim performance overall. 

Anyone have any experience with this, and could share some insight?

 

Thank you

[SteveW 1,792]

It can work but look at the maths; at 30fps you are possibly going to gain half an fps, maybe not that much in the long run. There is also the possibility of introducing instability with an untested setup. Better to see if you can reduce the load on core zero.

[Bob Scott 7,714]

It's generally not possible to clock one core independently from the rest.  A lot of folks misinterpret the "per core" multipliers (the ASUS BIOS terminology) to mean a mult that applies to a particular core, but those four "per core" mults are really a set of varied multipliers that are applied to the entire chip based on the number of active cores.  So a "per core" multiplier of 46 set in the 3-core ratio limit means that 46 will apply--to ALL active cores--when three cores are active, not that 46 applies to only the 3rd physical core.

Let's suppose you set the "1 core ratio limit" multiplier to 49, and 2/3/4 core ratio limits to 48.  What that would give you is a multiplier of 49 on all four cores if only one core is active, and 48 if two or more are active.  In the case of P3D/FSX, you'll always have at least two cores active, and usually all four.  So that approach would just make your machine run at 48 any time P3D is running.

There may be some high-end mobos used with extreme edition 2011-based CPUs that can do actual independent clocking of individual cores, but I don't believe there are any mainstream boards that would do that for a Devil's Canyon chip.

Regards

[westman 257]

Bob you ar right,  Its on x99 and up you can do that.

Mainstream  cpus follow  the intel  boosttable. 

Its only to read the intel tech  spec  over the cpu , all info is there. 

This is a common mistake  for exempel your core0 5.8ghz core1 4.8 core2 4.7 core3 4.7  you Think my cpu is Golden have it to 5.8ghz it boots nice in to windows sim run p3d without and problem, the thing is that you have run p3d at  4.7ghz .

Wy is not win crash,  if you booth in to sim it use all cores and if you have set energy ät balanced the cpu clock down until it get load then when start p3d it use all avilable cores it clock up the cpu to the core3 value. 

Its not the frist time this have been up here even experianced users have done this mistake.

[PinkPony 171]

On 4/21/2019 at 8:43 PM, w6kd said:

It's generally not possible to clock one core independently from the rest.  A lot of folks misinterpret the "per core" multipliers (the ASUS BIOS terminology) to mean a mult that applies to a particular core, but those four "per core" mults are really a set of varied multipliers that are applied to the entire chip based on the number of active cores.  So a "per core" multiplier of 46 set in the 3-core ratio limit means that 46 will apply--to ALL active cores--when three cores are active, not that 46 applies to only the 3rd physical core.

Let's suppose you set the "1 core ratio limit" multiplier to 49, and 2/3/4 core ratio limits to 48.  What that would give you is a multiplier of 49 on all four cores if only one core is active, and 48 if two or more are active.  In the case of P3D/FSX, you'll always have at least two cores active, and usually all four.  So that approach would just make your machine run at 48 any time P3D is running.

There may be some high-end mobos used with extreme edition 2011-based CPUs that can do actual independent clocking of individual cores, but I don't believe there are any mainstream boards that would do that for a Devil's Canyon chip.

Regards

Thank you very much for the thorough explanation, and for helping clear my misconceptions regarding the “per core” multipliers. 

I will remain at 4.8Ghz across all four cores using “sync all cores”, which has provided me a extremely stable system the past 4+ years.

Thank you you all for your input, it is greatly appreciated. 

 

On 4/21/2019 at 8:22 PM, SteveW said:

It can work but look at the maths; at 30fps you are possibly going to gain half an fps, maybe not that much in the long run. There is also the possibility of introducing instability with an untested setup. Better to see if you can reduce the load on core zero.

Seeing as a I run HT OFF (cores, 0, 1, 2, 3). I have set Activesky, vpilot, navigraph simlink, etc. to run on core 2, 3 only) via Project Lasso. 

My way of leaving more headroom to P3D on core 0,1. 

No Affinity for P3D (aka default setting). 

Any other suggestions would be appreciated!

Edited April 23, 2019 by calzonister

[SteveW 1,792]

Seems like you have things under control! 😎