• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

FEATURED Crosshair VI P-State modification for power savings.

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.

Johan45

Benching Team Leader Super Moderator
Joined
Dec 19, 2012
With the new Ryzen platform as soon as you modify the multiplier or FSB all power saving features are disabled, so in Windows your system will run at full speed regardless of OS power settings. Most people who are running their system as a daily driver still like to overclock it to get some additional (free) performance. It just seems that's not going to happen with the Ryzen. Or is it? If you're using an ASUS Crosshair VI Hero, they have included an option that allows you to alter the P-states. Essentially, this tells the CPU that it has a new top speed without disabling all the power savings that are built into it. This process isn't really plug and play without a bit of background work initially so you'll want to have a couple things handy before you start.
You'll need some paper and a pen/pencil for chicken scratching.
A calculator and a HEX<>Decimal converter. I have both of these on my Cell thanks to a free app called Hex plus from google play.

So let's dig in. First thing I want to get out of the way is, this is just a guide and you are altering the basic operation of your CPU and I'm not responsible for any damage you may incur. Use at your own risk. It has been brought to my attention that using P-state OC and having a failed boot can cause overvoltage upon reboot caused from the XFR on thw "X" models. To stop this from happening YOU MUST DISABLE TURBO/CPB
First navigate to the Advanced section in your BIOS and select the AMD CBS > ZEN Options > Custom Core P-ststes > Accept > Here's the P-state screen.


Zen options.jpg
Custom selection.jpg
Warning.jpg
pstates normal.jpg


We're going to start with P-State 0 so open that one by selecting custom in the drop down.


pstates stock.jpg

As you can see it shows the current max speed all cores which for my R7 1700x is 3400 without XFR, You should see this really cool warning at the bottom which basically says if you break something then you're warranty is void. The main points of interest here are Pstate0 FID and DID. FID is the number you'll want to change to alter the P0 state of your CPU. I have found it's best to leave the DID as it is. I have also tried changing the VID but haven't been successful yet. Seems any time I change it I get a top speed of 3000 in Windows. We'll take care of the voltage with an offset to the V_Core in the Extreme Tweaker section.
OK this si the formula we'll be working with for altering the Pstates going forward.
CPU Ratio = 0.25*FID/(DID*0.125)
Fist thing I need to point out is that the FID and DID you see in the BIOS page are hexidecimal numbers and need to be converted prior to plugging them into the formula. I'll go through with the stock values as an example first.

CPU Ratio = 0.25*FID/(DID*0.125)
CPU Ratio = 0.25*88/(8*0.125) converting the values from hex to decimal we get
CPU Ratio = 0.25*136/(8*0.125) as you see 8 is the same in both
CPU Ratio = 34/1 or 34 for the multiplier.

OK so to get a 40x multiplier we need to solve the equation for FID
CPU Ratio = 0.25*FID/(DID*0.125)
40 = 0.25*FID/(8*0.125)
40 = 0.25*FID/1
FID = 40/0.25
FID = 160 converted to Hex is A0

There is also a formula for finding your VID
Core Voltage = 1.55-0.00625*VID
Running through it with the stock values returns 1.35v which is what the BIOS says it is just above 1350000 uV or 1.35v. I know from testing I require ~ 1.4v for 4.0 GHz. This means I'll need a 0.05v+ offset added to the CPU Core voltage which I input on the tweaker page of the BIOS

Ok , we plug this new value into the BIOS page like so, with the offset added to the V_Core, it should boot straight to windows.

p 0 4.0.jpg

And it does, after Windows starts I open CPUz and voila 4.0 GHz

4.0.JPG

OK, got that to work now I set the power plan in Windows to Balanced but I'm getting a speed of 2.2GHz now which to me isn't really slow enough for a low power state

first 2195.JPG

So back into the BIOS I go, this time we'll be altering the Pstate2 section as you can see in the pic below I also have Pstate1 open showing 3.0 GHZ which is fine so no alteration needed.

p2 stock.jpg


So same as above we'll apply the formula and my goal is 1500 so a multiplier of 15x. You'll also notice the DID is a different value this time which I'm not going to change.

CPU Ratio = 0.25*FID/(DID*0.125) DID = C C= 12 in decimal
15= 0.25*FID/(12*0.125)
15= 0.25*FID/1.5
15*1.5= 0.25*FID
FID= (15*1.5)/0.25
FID= 90 which is 5A in Hexidecimal.

p2 1500.jpg

Ok now upon rebbot into Windows with the balanced power plan I have 4.0GHz top speed and 1.5GHz at idle. Seemed like it took Windows a bit to catch up to the change but with ~ 30 seconds the speed finally dropped down as well as the voltage as you can see here


1500.JPG
 
Last edited:
OP
Johan45

Johan45

Benching Team Leader Super Moderator
Joined
Dec 19, 2012
Thanks Blay, just thought it would be good for some to get a bit of clarification on this since it could be quite convenient for some users.
 

Dolk

I once overclocked an Intel
Joined
Mar 3, 2008
I so wanted to play with this stuff before you! I like it, I love it, and I am in the exact same boat as you.

RyZen overclocking is, meh to me atm. I like the idea of tweaking power settings to create "free" performance, but the overall gain may just not be worth it. I've still go a lot to do to catch up with those that have been playing with these chips for the past month.
 
OP
Johan45

Johan45

Benching Team Leader Super Moderator
Joined
Dec 19, 2012
I so wanted to play with this stuff before you! I like it, I love it, and I am in the exact same boat as you.

RyZen overclocking is, meh to me atm. I like the idea of tweaking power settings to create "free" performance, but the overall gain may just not be worth it. I've still go a lot to do to catch up with those that have been playing with these chips for the past month.

You're right about the overclocking, pretty much all of them tap out around 4.0 GHz depending on their bin, seems the 1800x might get to 4.2 on a good sample. I think performance/$$ goes to the 1700 myself. It'll pretty much do what the big brothers do. Seems to have a slightly lower ceiling but going from base of 3.0 GHz to 4.0Ghz is a sizeable gain in performance.
 

Dolk

I once overclocked an Intel
Joined
Mar 3, 2008
Agreed. The 1800x is definitely a buy and not OC. However, this does not mean that memory will be withdrawn from the overclocking want. In fact, I think memory should be the first section touched. If you can get your memory setup to the speed you want, you can than play with the core to your hearts content. How much gain, I guess would depend on the applications you use. My focus is right now gaming, and not benching as I've pretty much exited that scene. I'll be writing up some reviews of my own this weekend to showcase some of the data I've collected.
 

Bluefalcon13

Member
Joined
Jan 1, 2008
Location
Colorado Springs, CO
So to expand on the power saving concept of this post:

In that thread I linked to in the rumor/discussion post, The Stilt had stated there is a TDP limit function similar to the mobile A-series CPUs. He ran an 8-core limited to 30W with same fairly impressive numbers given its power constraints. Definitely smoked the low power Intel options.

I think Ryzen will truly shine in laptops. Ironically, that's where the consumer market is... After all how many of you all's family actually has and uses a desktop?
 

cdawall

Member
Joined
Feb 4, 2009
Location
cypress, tx
I wondered what all the values broke down to in there. Was way too lazy to figure them out myself. Excellent job!
 

seansplayin

New Member
Joined
Dec 15, 2011
Location
Twin Falls, ID
pstate voltage control

With the new Ryzen platform as soon as you modify the multiplier or FSB all power saving features are disabled, so in Windows your system will run at full speed regardless of OS power settings. Most people who are running their system as a daily driver still like to overclock it to get some additional (free) performance. It just seems that's not going to happen with the Ryzen. Or is it? If you're using an ASUS Crosshair VI Hero, they have included an option that allows you to alter the P-states. Essentially, this tells the CPU that it has a new top speed without disabling all the power savings that are built into it. This process isn't really plug and play without a bit of background work initially so you'll want to have a couple things handy before you start.
You'll need some paper and a pen/pencil for chicken scratching.
A calculator and a HEX<>Decimal converter. I have both of these on my Cell thanks to a free app called Hex plus from google play.

So let's dig in. First thing I want to get out of the way is, this is just a guide and you are altering the basic operation of your CPU and I'm not responsible for any damage you may incur. Use at your own risk. It has been brought to my attention that using P-state OC and having a failed boot can cause overvoltage upon reboot caused from the XFR on thw "X" models. To stop this from happening YOU MUST DISABLE TURBO/CPB
First navigate to the Advanced section in your BIOS and select the AMD CBS > ZEN Options > Custom Core P-ststes > Accept > Here's the P-state screen.


View attachment 189743
View attachment 189744
View attachment 189745
View attachment 189746


We're going to start with P-State 0 so open that one by selecting custom in the drop down.


View attachment 189747

As you can see it shows the current max speed all cores which for my R7 1700x is 3400 without XFR, You should see this really cool warning at the bottom which basically says if you break something then you're warranty is void. The main points of interest here are Pstate0 FID and DID. FID is the number you'll want to change to alter the P0 state of your CPU. I have found it's best to leave the DID as it is. I have also tried changing the VID but haven't been successful yet. Seems any time I change it I get a top speed of 3000 in Windows. We'll take care of the voltage with an offset to the V_Core in the Extreme Tweaker section.
OK this si the formula we'll be working with for altering the Pstates going forward.
CPU Ratio = 0.25*FID/(DID*0.125)
Fist thing I need to point out is that the FID and DID you see in the BIOS page are hexidecimal numbers and need to be converted prior to plugging them into the formula. I'll go through with the stock values as an example first.

CPU Ratio = 0.25*FID/(DID*0.125)
CPU Ratio = 0.25*88/(8*0.125) converting the values from hex to decimal we get
CPU Ratio = 0.25*136/(8*0.125) as you see 8 is the same in both
CPU Ratio = 34/1 or 34 for the multiplier.

OK so to get a 40x multiplier we need to solve the equation for FID
CPU Ratio = 0.25*FID/(DID*0.125)
40 = 0.25*FID/(8*0.125)
40 = 0.25*FID/1
FID = 40/0.25
FID = 160 converted to Hex is A0

There is also a formula for finding your VID
Core Voltage = 1.55-0.00625*VID
Running through it with the stock values returns 1.35v which is what the BIOS says it is just above 1350000 uV or 1.35v. I know from testing I require ~ 1.4v for 4.0 GHz. This means I'll need a 0.05v+ offset added to the CPU Core voltage which I input on the tweaker page of the BIOS

Ok , we plug this new value into the BIOS page like so, with the offset added to the V_Core, it should boot straight to windows.

View attachment 189748

And it does, after Windows starts I open CPUz and voila 4.0 GHz

View attachment 189749

OK, got that to work now I set the power plan in Windows to Balanced but I'm getting a speed of 2.2GHz now which to me isn't really slow enough for a low power state

View attachment 189750

So back into the BIOS I go, this time we'll be altering the Pstate2 section as you can see in the pic below I also have Pstate1 open showing 3.0 GHZ which is fine so no alteration needed.

View attachment 189751


So same as above we'll apply the formula and my goal is 1500 so a multiplier of 15x. You'll also notice the DID is a different value this time which I'm not going to change.

CPU Ratio = 0.25*FID/(DID*0.125) DID = C C= 12 in decimal
15= 0.25*FID/(12*0.125)
15= 0.25*FID/1.5
15*1.5= 0.25*FID
FID= (15*1.5)/0.25
FID= 90 which is 5A in Hexidecimal.

View attachment 189752

Ok now upon rebbot into Windows with the balanced power plan I have 4.0GHz top speed and 1.5GHz at idle. Seemed like it took Windows a bit to catch up to the change but with ~ 30 seconds the speed finally dropped down as well as the voltage as you can see here


View attachment 189753

What a great write up! Thank you!!!

do you know if the voltage control in the Pstate is still not working on the new beta bios 9943? Also is there a way to control the turbo core voltage? Where I'm stuck around 4.1ghz on all 8 cores I was hoping I could tinker with extremely high voltages if they would only be applied to the cores being accelerated via XFR. Basically I noticed when I OC'd via the FSB only it does not disable XFR, basically it was trying to run my boosted core up to 4.4 or 4.5ghz which was not stable @ the 1.5vcore. I was wanting to put all cores @ 4.1ghz and then have the single boosted core rocket up to 4.5ghz. I have an extremely custom loop and I can still only cool 1.5vcore on a stress test. I plan to add a very power peltier capable of moving up to 375watts (@ 0° T delta) very soon hoping to get to 4.5ghz on all cores but being able to ramp only a few cores significantly higher would rock.
Caution - A word of warning. Using Asus's AI Suite software and running the "5 way optimization" may put your vcore very very high. on day 1 or this build I ran it and it overclocked my cpu with 4.2ghz @ 1.595 vcore. Basically it loads the cores with work and continues raising the mhz and vcore until you hit the thermal limit of 85C. On a water cooling system with a short stress test it will just keep going higher and higher, I think raising the stress test time to something above the default setting of 30 seconds between steps may make it the thermal limit sooner and at a safer voltage for 24/7 daily driver.

thank you for your time and I welcome any information.
 
OP
Johan45

Johan45

Benching Team Leader Super Moderator
Joined
Dec 19, 2012
First there's another "official" BIOS derived from the 9943,9945 versions. It's 1201 here http://redirect.viglink.com/?format...rosshair VI overclocking thread&txt=BIOS 1201
The Pstate 0 VID still doesn't work correctly AFIK but the lower ones 1,2 etc. are adjustable and there's no way to keep XFR working and get the speeds you want using the multiplier.
I should caution you that we don't know the effects of sustained high voltages on this new CPU yet and AMD recommends 1.35V for 24/7 with a max of 1.45V with a disclaimer that it may shorten the life of your CPU. That being said they're your parts and if you want to risk them it's your loss in the end. The peltier isn't likely going to get you what you want either, I run a cold loop capable of maintaining -20°C water for a period of time and I can't maintain anything that fast with reasonable voltage. Best I had was my 1600X at 4.3 for benching only, the CPU responds to cold but I don't think the peltier is cold enough.
 

seansplayin

New Member
Joined
Dec 15, 2011
Location
Twin Falls, ID
First there's another "official" BIOS derived from the 9943,9945 versions. It's 1201 here http://redirect.viglink.com/?format...rosshair VI overclocking thread&txt=BIOS 1201
The Pstate 0 VID still doesn't work correctly AFIK but the lower ones 1,2 etc. are adjustable and there's no way to keep XFR working and get the speeds you want using the multiplier.
I should caution you that we don't know the effects of sustained high voltages on this new CPU yet and AMD recommends 1.35V for 24/7 with a max of 1.45V with a disclaimer that it may shorten the life of your CPU. That being said they're your parts and if you want to risk them it's your loss in the end. The peltier isn't likely going to get you what you want either, I run a cold loop capable of maintaining -20°C water for a period of time and I can't maintain anything that fast with reasonable voltage. Best I had was my 1600X at 4.3 for benching only, the CPU responds to cold but I don't think the peltier is cold enough.
Thank you for your reply Johan45, well that's unfortunate there is no way toto keep xfr and independently control the voltage only for the boosted core. That's unfortunate that even operating at -20C you only got to 4.3ghz☹️ What kind of vcore were you running when you got to 4,3ghz and were you able to keep the core at -20C even under load when benchmarking? And also thank you for the heads up on the new bios version
 
OP
Johan45

Johan45

Benching Team Leader Super Moderator
Joined
Dec 19, 2012
For V_Core probably around 1.45V and no My loop won't hold the cold that long. I have a rad/res in a deep freezer so as soon as I start benching it starts to warm up.