Do you enable Haswell C6/C7 power saving?

[bemylove]

What is C6/C7 state for Haswell?
Exclusive power-savings and lower temps!

 

[bemylove]

How to enable?
On typical bios settings:

CPU C STATES: ENABLED - This is set to AUTO by default, change it to ENABLED and under CPU C STATES the following will appear, change as outlined:

ENHANCED C1: ENABLED

CPU C3 REPORT: ENABLED

CPU C6 REPORT: ENABLED

C6 LATENCY: SHORT

CPU C7 REPORT: ENABLE

C7 LATENCY: LONG

PACKAGE C3 STATE REPORT: C6

BUT you make sure you have these supported Haswell PSU first!
http://techreport.com/review/24897/the-big-haswell-psu-compatibility-list

Benchmarks show no noticeable loss in CPU performance, but you win a few more watts and temps savings
http://www.legitreviews.com/what-en...ates-do-on-the-core-i7-4770k-haswell-cpu_2217

 

[bemylove]

My personal testing prove same and positive.

2-3C drop in average temps, CPU benchmark scores remain same. But SSD crystalmark scores drop 5%.

Using Hwinfo monitoring, surfing HWC the CPU and Package voltage hovers between 0.00v to 0.1v! yes that is 2 decimal pts, 0v!

Before enabling, they would be around 0.35v to 0.75v.

Super low voltage idle and power up on Overclocking. sibei song.

I believe also need to enable "adaptive voltage" for best experience.

 

[bemylove]

Overclocked 5960X 4.4(core)/4.2(uncore)Ghz, normal web-surfing use less than 0.1v for the vcore and package on average.

Cpu averages at ambient room temps +2dC, without aircon.

 

[Mikiberry]

Great way to guarantee hardware longevity while having great clocks when needed.

 

[Toby88]

Using Superflower Leadex PSU 850W, not sure if it's supported?

 

[Maeda_Toshiie]

Using Superflower Leadex PSU 850W, not sure if it's supported?

If use direct DC-DC conversion for 3.3V and 5V, likely yes. If group regulated, probably be not.

 

[zzzzzzz]

reused my antec neo eco 450w modular psu for my haswell build
never try the power saving
dunno if supported by psu

 

[bemylove]

reused my antec neo eco 450w modular psu for my haswell build
never try the power saving
dunno if supported by psu

not supported afaik.
time to upgrade psu for lower power cpu?

 

[Montoya]

Tried it previously but switched it off. Somehow there is some lag when it's switching between different states.

 

[MacClipper]

How to enable?
On typical bios settings:...

Good timely thread.

Check this ROG page for recommended detailed settings, seems the only place where I can find info on the C7s state
http://rog.asus.com/253612013/labels/rog-exclusive/maximus-vi-power-saving-power-tuning-guide/

HTH

 

[bemylove]

Thanks uncle Mac! Such tweaking makes overclocking more fun and efficient!

 

[MacClipper]

Running with C7s enabled, still stable and steady pom pi pi!

Click!

 

[bemylove]

Bump for more to use 0v idle vcore.

Sibeh songz to see your Haswell turbo up when encoding only to go back to 0v when done.

It is like DBZ, use saiyan form to fight scrubs, than turbo to SSJ to fight boss first form and only turbo to SSJG to fight Beerus!

 

[weione]

how to enable on asrock mobo?

got a guide to follow?

 

[ondooy]

too bad, can't use this...

 

[bemylove]

how to enable on asrock mobo?

got a guide to follow?

Check Uncle Maclipper link above.

It is the best form of overclocking and available only for Haswell CPU. Haswell FIVR is awesome!

Not sure Skylake can do 0v vcore without FIVR.

 

[bemylove]

too bad, can't use this...

Why cannot leh?

I think Haswell-E is perfect use C-states/Adaptive voltage overclocking.
With more cores, you want them to be in 0v state for low power/low temp use, and full power up when loading!

I found Haswell-E cores default voltage is lower than mainstream Haswell processors.
What is your idle vcore without turn on C-states?

 

[Ark Law]

Can't hit as low as Mac's insance 0.016V. Dunno how to config properly, so I just set C7S, enable all power saving in bios and set to adaptive voltage

 

[ondooy]

when not playing, i run it at full load for grid computing...