Vcore concerns

Nov 26, 2005
15,194
403
126
.0941 V at idle
1.294 V running memtest HCI (load) EDIT 2: :eek: just seen a 1.305 V for a stock i7 920 under load! The Vcore setting is on Auto
With Vdroop: EVGA board
I have the latest bios for the mb (59)

EDIT 1: sorry, forgot to add, this is a stock i7 920 (Gamer)
 
Last edited:

Ben90

Platinum Member
Jun 14, 2009
2,866
3
0
What's the concern exactly?

Intel says the maximum Vcore for bloomfield is 1.55v. You're not going to fry the chip with 1.305v.

http://www.overclock.net/intel-cpus/472058-intel-cpus-maximum-voltages-temps.html

This is very bad information. While Intel does list the "Absolute Maximum Vcore" at 1.55v, they are not using the same definition of maximum as we are. Do not set your Vcore to 1.55v as this will severely limit the life of the chip.

If you look at the technical documents the actual maximum Vcore within operating limits is a function of the VID and Amperage. The maximum VID on Bloomfield processors is 1.375v at zero Amps. As move amperage goes through the processor, the maximum Vcc goes down. At 100 Amps, the maximum operating Vcc is 1.3v. At 140 Amps, the maximum operating Vcc is around 1.27v.

Section 2 covers voltages and stuff
http://docs.google.com/viewer?url=http://download.intel.com/design/processor/datashts/320834.pdf

DO NOT SET YOUR VCC TO 1.55V!
 

EarthwormJim

Diamond Member
Oct 15, 2003
3,239
0
76
This is very bad information. While Intel does list the "Absolute Maximum Vcore" at 1.55v, they are not using the same definition of maximum as we are. Do not set your Vcore to 1.55v as this will severely limit the life of the chip.

If you look at the technical documents the actual maximum Vcore within operating limits is a function of the VID and Amperage. The maximum VID on Bloomfield processors is 1.375v at zero Amps. As move amperage goes through the processor, the maximum Vcc goes down. At 100 Amps, the maximum operating Vcc is 1.3v. At 140 Amps, the maximum operating Vcc is around 1.27v.

Section 2 covers voltages and stuff
http://docs.google.com/viewer?url=http://download.intel.com/design/processor/datashts/320834.pdf

DO NOT SET YOUR VCC TO 1.55V!

That table is based on temperature too. In order to meet Tcase limits with cooling supplied by Intel (able to dissipate 130W), you'd follow that chart.

You are correct at saying 1.55V is not safe to use if you're concerned about long term life of the processor. Thank you for correcting me on that.

Just curious, why does Intel use Vcc for their term? Isn't that usually for BJT circuits?
 
Last edited:

tweakboy

Diamond Member
Jan 3, 2010
9,517
2
81
www.hammiestudios.com
Stop obsessing about your vcore , take it out of auto and you choose the vcore you want. You need to keep bumpin it up. Eventually you have reached your max OC and what not..
 

MJinZ

Diamond Member
Nov 4, 2009
8,192
0
0
i7 920s range from around 1.25V - 1.30V on Auto Vcore. You just got a less than stellar chip.

My CPU auto detects at 1.27V. I had one that only used 1.24V.

I do not need any additional Vcore until I reach 3.8ghz overclock. I need to up Vcore to 1.35V for a 4.2ghz overclock.

So in short... what you're experiencing is completely normal.
 
Nov 26, 2005
15,194
403
126
I'm currently at 1.15xxx Vcore with droop between 1.13 - 1.14 vcore

Another issue I am having is the motherboard keeps running the primary PCI-E 2.0 slot at x8 instead of x16. Actually it is acting kinda flakey. One time it read x16, and the next it runs at x8... could this also be a power saving feature?
 
May 13, 2009
12,333
612
126
Set your vcore to 1.1875v. You could just leave it auto and it's not going to hurt anything. I undervolted my CPU to 1.125 in bios and overclocked it to 3.3ghz with hyperthreading and turbo on. Under load in windows in shows voltage as 1.03 for CPU. I have no doubt in my mind your chip would run at stock speeds at 1.1875 in bios that's why I suggest that.
 
Nov 26, 2005
15,194
403
126
Hardware or software?

I have a PCI-e sound card in the 1x slot but that shouldn't ? cause the lanes to back off to x8 from x16 ???
 
Nov 26, 2005
15,194
403
126
Well I uninstalled the sound card and disabled the PCI-e 1x slot in bios, then took out the sound card and on the next boot, it shown PCI Express 2.0 x 8; I rebooted again and it now shows PCI Express 2.0 x 16 ???

EDIT: rebooted and it's showing PCI Express 2.0 x 8 lol :\
 
Last edited:
May 13, 2009
12,333
612
126
some boards default to 2x8 when using both slots or 16 if using just one gpu.

read up on your board.
 

MJinZ

Diamond Member
Nov 4, 2009
8,192
0
0
I just noticed the OP has the same board as I do, I would have to say you are either using the incorrect PCi-E slots (you MUST use Lane 1 (closest to NB) and Lane 3 for PCI-E x16 operation).

Also, some people report that using the PCI-E x1 slot WILL affect dual 16x usage (cause one to drop to 8x).

But since I never used it (I have 2 fans on the NB for cooling), both of my Crossfire 5870s have always read as x16.
 
Nov 26, 2005
15,194
403
126
I just noticed the OP has the same board as I do, I would have to say you are either using the incorrect PCi-E slots (you MUST use Lane 1 (closest to NB) and Lane 3 for PCI-E x16 operation).

Also, some people report that using the PCI-E x1 slot WILL affect dual 16x usage (cause one to drop to 8x).

But since I never used it (I have 2 fans on the NB for cooling), both of my Crossfire 5870s have always read as x16.

With nothing else but the two video cards in, it still comes up as x 8; using lanes 1 & 3
 

aigomorla

CPU, Cases&Cooling Mod PC Gaming Mod Elite Member
Super Moderator
Sep 28, 2005
21,077
3,577
126
okey slot 1 and 3.. is im assuming first and last?

Im guessing its because u have a card occupied in the last slot which would make your config tri sli.. and drop the lanes to 8x since ur not on a 759.

Did you try slots 1 and 2?
 
Nov 26, 2005
15,194
403
126
okey slot 1 and 3.. is im assuming first and last?

Im guessing its because u have a card occupied in the last slot which would make your config tri sli.. and drop the lanes to 8x since ur not on a 759.

Did you try slots 1 and 2?

In the order from the NB (top) to the last PCI Express slots:
1st - 1x
2nd - 16x (primary card)
3rd - this should be a 16x slot but the print on the mb says 8x (the manual says it's a 16 slot) - (empty)
4th - PCI (empty)
5th - 16x/8x (secondary card)
6th - 8x/4x (empty)

In further trouble shooting, I've taken out the card that I originally had as the primary card and put in the other 5870 into the primary slot, leaving the rest of the slots empty with just the one 5870. The next boot, GPUz shown 8x mode. I rebooted again and it has consecutively shown 16x mode the past 4-5 boots.

EDIT: it stayed at 16 mode with one card until 2 boots after I installed the crossfire card. Now it's back to the same old 8x mode for primary card, 16 mode for secondary card: in same config as above :(

I'm working with EVGA's troubleshooting team. I'm starting to think it's a flaky bios.
 
Last edited:

aigomorla

CPU, Cases&Cooling Mod PC Gaming Mod Elite Member
Super Moderator
Sep 28, 2005
21,077
3,577
126
yeah i know.. but im just trying it wont hurt now will it?

On my 759 i have it on the first and second slot.. the third is left empty.
 

solofly

Banned
May 25, 2003
1,421
0
0
Anything over 1.225v is considered overvolting according to my Asus motherboard so be careful...

Edit:
lol I just tried Auto on my 965 for the first time ever and it defaults to 1.256v

Edit2:
Now that I've loaded into windows on Auto, utilities such as CPU-Z indicate voltage of 1.36

Edit3:
Rebooted and went into BIOS the second time and now my default cpu voltage (AUTO) shows 1.344
 
Last edited:

aigomorla

CPU, Cases&Cooling Mod PC Gaming Mod Elite Member
Super Moderator
Sep 28, 2005
21,077
3,577
126
btry if u complain about your voltage one more time i will fish slap you on the forum.

Why? Becuase stock voltage does not really mean anything.

Ive had ES branded cpu's which had nasty nasty start up voltages of 1.325 yet they would be classed as cherries on the forum.

Dont believe me? ask gillbot.

You will NEVER know what the cpu can do without pushing it to the extremes.

Cpu's come in 2 flavors from what im seeing.

1. Leaky = requires a lot of vcore because of leaky. However because there leaky, they are built stronger, and can take more stress. So they in turn have overclocked higher, but required a high vcore.

2. Super Conservative. = my default on the cpu was 1.097 No JOKE!
HOWEVER! if i put 1.4V + higher the stupid cpu WOULD NOT BOOT!
HOWEVER! it was another "cherry" classed cpu.

So dont worry about default vcore... worry about your OC vcore because ur not running that cpu on stock forever are you?
 
Nov 26, 2005
15,194
403
126
btry if u complain about your voltage one more time i will fish slap you on the forum.

Why? Becuase stock voltage does not really mean anything.

Ive had ES branded cpu's which had nasty nasty start up voltages of 1.325 yet they would be classed as cherries on the forum.

Dont believe me? ask gillbot.

You will NEVER know what the cpu can do without pushing it to the extremes.

Cpu's come in 2 flavors from what im seeing.

1. Leaky = requires a lot of vcore because of leaky. However because there leaky, they are built stronger, and can take more stress. So they in turn have overclocked higher, but required a high vcore.

2. Super Conservative. = my default on the cpu was 1.097 No JOKE!
HOWEVER! if i put 1.4V + higher the stupid cpu WOULD NOT BOOT!
HOWEVER! it was another "cherry" classed cpu.

So dont worry about default vcore... worry about your OC vcore because ur not running that cpu on stock forever are you?

Haha thanks :)

After thinking about those volts, I'm persuaded to believe that "Auto" volts are dictated by the motherboard not from how the chip is and btw it's running fine at 1.15xxx Vcore.

With the MB orientation on the 800D I find that the NB needs active cooling over it to keep it below 40*c which to me is fairly high in 72*f ambients. How does your full chip-set h20 cooler work with the 759?
 

aigomorla

CPU, Cases&Cooling Mod PC Gaming Mod Elite Member
Super Moderator
Sep 28, 2005
21,077
3,577
126
How does your full chip-set h20 cooler work with the 759?

Capture-3.jpg


:)

only see 40c on vregs on a warm day.
 
Last edited: