i5-2500K - VID, Vcore - some doubts.

[BambOOs]

Hello!

First of all, this is my PC specs:

CPU: I5-2500K
MB: AsRock P67 PRO 3 B3
GPU: Gigabyte GTX 970 G1
RAM: 8 GB DDR3 Kingston HyperX Black 1600 MHz
PSU: XFX TS 550W
CASE: SPC Gladius M40
CPU COOLER: SPC Grandis v2

After trying to play Watch Dogs on Ultra settings etc (I know it's just bad optimized piece of software, but apart from this I very like it as a game), I saw some CPU bottleneck in some areas. It was just my guess, so I tried to overclock my CPU to ~4.5 GHz to see if there will be any improvement in FPS.

So I went into UEFI and changed some settings like voltage in OFFSET mode, disable C states, set Level of LLC, etc.

Please correct me if I'm wrong:
1. VID - it is "default" voltage on stock speed. Thanks to this, motherboard knows what voltage should apply to CPU.
2. Vcore - actual CPU voltage, depends on current level and type of load, power saving modes.

I have some doubts of above things. It looks like VID of my CPU is 1.28v according to CoreTemp or RealTemp. Measured with 100 % load (LinX)

While OCing I set offset to +0,005, LLC to Level 3 and multiplier to 45.

PC booted fine, so I started to test stability. Here comes my doubts:

Under 100 % load in LinX, CPU-Z shows 1.35v CPU Voltage, but VID measured in Real/CoreTemp showed 1.4 V.

I thought Vcore will be at 1.28 + 0.005 = 1.2805v

And why VID is so high?

Please help me to understand these things.

Thanks in advance.

Greetings.

 

[Folterknecht]

https://translate.google.com/transl...5-oc-guide-faq-847597.html&edit-text=&act=url

 

[OneMoar]

because this is how LLC works
reduce the LLC and vcore untill your load-voltage is <1.25

 

[FR@NK]

While OCing I set offset to +0,005, LLC to Level 3 and multiplier to 45.

The VID changes depending on the clock speed. So using a higher multi will increase the voltage.

I use a negative offset to keep within safe voltages at higher multipliers.

 

[BambOOs]

Thanks for answers

I'm wondering, why my motherboard boosted vcore to 1.35?

I thought LLC is helpful in decrease Vdroop.

 

[Mussels]

Friend, comrade! Us 2500K users must unite

1.35V - 1.40V is safe to use 24/7, and should net you 4.5GHz+ - in my case i get 4.7GHz from 1.35V for 24/7 stable daily use

LLC and such decrease VDROOP, by boosting load voltages. It can boost higher than your selected voltage - this varies between mobos so you may have to mess around with that.

Having a K chip, dont worry about offsets and such - just run the 'default' settings with 1.4V Vcore and test one multi at a time (i use 10 passes of intel burn test as a basic test for this stage), and see if its stable or overheating (performance will drop if you thermal throttle).

Once you get a stable clock, tweak the voltage down slightly and repeat the testing. Once you think its stable with results you're happy to keep long term, change it to 100 rounds of IBT, test gaming, etc etc.

Feel free to Enable EIST/C-States and other power saving modes to save power at idle - i leave all mine on with no negative effects.

As for your voltage boosting, disable turbo - you're OCing it anyway, so dont have two conflicting things happening at once, turbo changes the amount of active cores, multi and voltages - do it all manually instead.

 

[jboydgolfer]

Doesnt get much better these days,than Oc'ing a sexy sb 2500k
Good memories, great perf.
After going to a 4690k, ive seen no real life performance jumps, ride those 2500's until you no longer can folks.
Intel guffed up on that chip.no money in long life chips

 

[Mussels]

Doesnt get much better these days,than Oc'ing a sexy sb 2500k
Good memories, great perf.
After going to a 4690k, ive seen no real life performance jumps, ride those 2500's until you no longer can folks.

according to a thorough single benchmark i did (intel burn tests Glfops result) my OC'd 2500K is faster than a 6600K at stock. Cant beat that performance, for how old it is.

 

[jboydgolfer]

according to a thorough single benchmark i did (intel burn tests Glfops result) my OC'd 2500K is faster than a 6600K at stock. Cant beat that performance, for how old it is.

i agree 100%
they broke the mold (rightfully So) when they stopped production on those puppies.
I remember driving down to Microcenter buying my 2500k, and being able to OC it right to 4.6-4.7Ghz Just on multiplier increases.
I since sold mine to a TPU member, but its got a good home. I didnt need it any longer, but Anyone who doesnt want to spend the money needlessly, Hold onto them, and Dont scratch that "upgrade itch".

 

[BambOOs]

TPU community is just awesome.

So, this is normal, that my mobo is boosting voltage, right?

If I disable turbo, then this boost will be lower? Please correct me if I'm wrong.

Does voltage boost depends on multiplier?
Higher multiplier = Higher voltage boost?

 

[jboydgolfer]

it would stand to reason that your motherboard is correcting for the increased Power requirements of Your CPU, you increasing Multiplier=Voltage is increased.

I would assume it would be like if you stepped on the Gas pedal in a car, the engine will call for more fuel.

 

[Mussels]

TPU community is just awesome.

So, this is normal, that my mobo is boosting voltage, right?

If I disable turbo, then this boost will be lower? Please correct me if I'm wrong.

Does it voltage boost depends on multiplier?
Higher multiplier = Higher voltage boost?

Turbo has prest voltages and multipliers. Basically, if you're OCing via the multi (which you do on K chips) disable turbo so its not conflicting.

Lets say turbo ran at 1.4V with one core at 4Ghz (made up numbers)
You could OC to 4.5Ghz on all 4 cores at 1.3V - but when only using a single core it could 'turbo' to 1.4V for no reason.
Same goes for LLC/offset voltages, they get applied to the turbo voltages too - which you cant control.

 

[BambOOs]

I read somewhere that VID is thing to not worry about - is it true?


I thought voltage regulation looks like this:

1. We increase multiplier, so VID also increases.
2. As VID is default voltage that mobo should apply at stock values, then higher multiplier means higher VID, and higher VID means higher default voltage.

I see that VID is higher than Vcore. So: Vcore = VID - Vdroop - pover savings modes.

Please tell me if I understand this correctly.

If not, please correct me

 

[Mussels]

Default voltage for its default clock speeds.
So if your CPU with EIST has some default values - lets say 1GHz, 1.6GHz, 3.2GHz - it has a voltage programmed in for each of those it tested stable at.

Again when OCing a K chip (and 1155 in general) you can only OC via the multiplier, so you're only dealing with the max voltage - so its irrelevant really.

 

[EarthDog]

To be clear. VID = Stock voltage. Anything above that is VCore....... though VCore is also VID WHEN AT STOCK VOLTAGE.

 

[BambOOs]

1. At stock settings my VID is ~1.28 v (under load), but CPU-Z says ~1.25v under load. This difference has to do with Vdroop etc. right? LLC is on level 5.
2. At 4.5 GHz with +0.005 offset my VID is 1.4, but cpu-z says 1.35 under load. LLC is on level 3 so Vdroop should be smaller. Here is my question: mobo boosted voltage to 1.35 (seems to be Vcore) or 1.4 (VID in RealTemp)? And 1.35 value is just 1.4 after vdroop etc?

 

[EarthDog]

Again VID is NOT anything past your stock voltage. That is VCORE.

That isn't vDroop, the difference between what two pieces of software read (you said both were under load...). VDroop is the difference between idle voltage in Windows and load voltage in windows.

 

[Mussels]

1. At stock settings my VID is ~1.28 v (under load), but CPU-Z says ~1.25v under load. This difference has to do with Vdroop etc. right? LLC is on level 5.
2. At 4.5 GHz with +0.005 offset my VID is 1.4, but cpu-z says 1.35 under load. LLC is on level 3 so Vdroop should be smaller. Here is my question: mobo boosted voltage to 1.35 (seems to be Vcore) or 1.4 (VID in RealTemp)? And 1.35 value is just 1.4 after vdroop etc?

it could be doing that, yes. VID could be 'voltage you're meant to be running' and Vcore is what its really running. Software readings arent too accurate so dont waste too much time focused on this.

 

[BambOOs]

Okey, so how to read actual cpu voltage on Windows?

 

[EarthDog]

With a digital multi-meter and voltage read points on your board if you have them. If you don't, then you really cant.

Why are you (all) getting caught up in the minutia? All you have is what you are reading from whatever pieces of software. I would pick one and go with it.

 

[BambOOs]

Again VID is NOT anything past your stock voltage. That is VCORE.

That isn't vDroop, the difference between what two pieces of software read (you said both were under load...). VDroop is the difference between idle voltage in Windows and load voltage in windows.

So, as an ~actual~ CPU voltage, should I take CPU-Z's Vcore or Real/CoreTemp VID value?

 

[Mussels]

Let me put it this way: Pick one, lets say CPU-Z. Rely on that number, even if its inaccurate.

You are only using it for comparison on your board, with your CPU, with your system. The only purpose for that number is to see if it goes higher or lower as you change settings - that is all.


To be honest you could totally ignore those software readings and only go by what you set in the BIOS, thats how i got my OC.

 

[EarthDog]

So, as an ~actual~ CPU voltage, should I take CPU-Z's Vcore or Real/CoreTemp VID value?

CPUz is what I would use. Or, as Mussels said, the BIOS.

What I do is see what the voltage is in the BIOS.... then see what idle is in CPUz, then see what load is in CPUz and go by that.

 

[BambOOs]

Hmm, then it's seems VID is just stock voltage (@ stock) and after OC it is just value of voltage CPU "thinks" it need to have. Right?

And in case of my mobo and CPU, when I set multiplier to 45x, mobo set 1.4 voltage, but under load it drops to 1.35 thanks to Vdroop (LLC settings).

Offset depends on VID or Vcore?

Example:

When I choose "+0.020" offset, what will increase? Vcore or VID? Actually @4.5 GHz I have 1.4 VID and 1.35 Vcore so it will be 1.42 VID OR 1.37 Vcore?

 

[EarthDog]

Let me put this another way............

VID = Voltage I Demand (at stock).
VCore = Voltage I get/have.

I don't bother with offset so I am not sure...

You are still are not getting it . Again, VID = stock voltage. Period. NOTHING ELSE. Anything else above or below that ONE value is considered VCORE. VID can also be Vcore (and vice verssa) if the Vcore set is the same as VID(stock) voltage.

But again VID = ONE value. Stock voltage. Its wrong to call voltage above/below stock VID.