core 2 duo undervolt

i decided to undervolt my Core 2 Duo to reduce the load temps of it and am having some confusion right now. If i use RMClock, the voltages are 1.06 something for the lowest and NHC shows .9500 for the lowest. Right now i have my T7200 set at .9500 for all multipliers except 12X which is 1.0250v. does this seem right or is something wrong? anyhelp would be appreciated

 

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I am also using RM clock with a T7200. The minimum voltage is 0.95V and, after testing with two copies of Prime 95 running at the same time (in order to load both cores) and starting to get errors at 0.975V, I have set the 12X voltage as 1.012V with intermediate voltages interpolated.

John

 

Ah, I was just about to post a new topic asking about how Core 2 Duo processors behave when Prime95 is running.

So, when running two copies of Prime95 on a stock T7200 (ie. normal voltage), do you get errors and if so, after how long ?

What laptop are you running on ?

 

My notebook is a Samsung X60plus. You should not get any errors arising from running two copies of Prime 95 at the same time at normal voltage (each has to be in its own folder). I was able to undervolt my T7200 to 0.975V before errors started. While undervolting the Core Duo / Core 2 Duo CPUs doesn't give any significant increase in battery life because the low end voltage is locked at 0.95V (presumably to create a market for lower voltage CPUs), dropping the maximum voltage reduces the heat generated when the CPU is under load.

John

 

Thanks for the info John. I'm new when it comes to all things over-clocking and undervolting, so excuse me if the next question is obvious.....

Does undervolting the CPU result in less performance then (this is what I imagine happens), or does it just reduce the amount of heat generated ?

If it does result in less performance, then why does the battery life not increase (they seem to go hand-in-hand) ?

 

Undervolting does not reduce performance. The CPU still runs at the same speed (or set of speeds). The basis for undervolting is that the standard voltage settings provide for the range of CPUs which make it off the end of the production line. Most recent CPUs will safely run at lower voltages. The Dothan Pentium M CPUs were excellent undervolters because it was possible to significantly drop the voltage used at the minimum CPU speed (which is where the CPU runs most of the time). The more recent CPUs have been locked into narrower voltage ranges so the benefits of undervolting are reduced. There will be an improvement to battery life if you leave the power management on "Performance on Demand" and give the CPU some work because the CPU will use less power when it is running at faster than the minimum speed.

Undervolting is almost the inverse of overclocking. The latter increases the voltage so the CPU remains stable at higher than rated speeds. If my CPU will run at 2GHz at 1V then I'm sure that it would run faster than 2GHz at the rated voltage. Effectively, I've got a T7400 or T7600 which has its legs tied together. Sales of these faster CPUs are constrained by pricing, not availability (which used to be the case).

John

 

I dont quite understand when you say "my CPU @ 2Ghz @ 1V > 2Ghz @ Rated V"....

In any event, I undervolted my T7200 T60 WS to .975, and now my battery life @ 100% Battery is near 6.5 hours, which is the rated battery life for my 9-cell. Without it it is nearly 4.5-5! Go figure

 

Tool- RMClock

Scanario 1-
Account - web surfing.
Backgroud processes-
Antivirus, Transparency, Dock with big PNG Icons, 3D effects (WinFlip), Yahoo widget engine with 10 widgets (Including a Big Animated Analog Clock)

Foreground tasks- Opera, Yahoo messenger, MSN, Rediff, Skype.

RMClock profile-performance on demand.
All Mulitpliers at 0.95V (the minumum option) 6X~10X
Systmem Rock Solid!
Usually runs at 6X (1ghz)
Core temps- 23.C ~ 33.C

Fan/Noise -Absent.
Graphics temp- ~40.C

Scenario 2-
Plain undervolting

Background tasks- Minimum/Absent
Foreground - Game (NFSMW,DOOM, Call of duty etc)

Multiplier 10X 1.667 Ghz at 0.96 (Just a Notch higher Than Min) STABLE
Lower Mulitpliers at 0.95V

Aquamark score - 43K
Temps 50~60.C
Fan at low sppeds
Graphics temp 50~60.C

Before Undervolting-
Multiplier - Switches 10X 1.667Hgz at 1.26V and 1Ghz At 0.95V
Websurfing Temp- 40~58.C
Gaming temp- 80~90.c (Ouch! My pants!)
FAN- Huh! Its better called a Hairdryer!

Config-
1>Custom HP DV 8/9XXX series (Import
from Singapore)

2>17.2 in Widescreen, 1400X900
Dual lamp,Ultra bright (OMG!!!!!
Gorgeous!!!) 5:3 Aspect ratio

3>Intel Core QUAD, 1677Mhz,667
Mhz FSB , 2MB L2 cache, 31W
socket 479

4>Intel 945PM Chipset,Pcie X16
support,Sata Support,Upto 2G RAM
support.

5> 1 GB DDr2 667 mhz RAM.

6>Nvidia GF 7400Go OEM SLI!!!!
- 2X nvidia G72 cores at 400Mhz
each + 512 MB RAM (700Mhz)each
OC'd to 564/864 For gaming Profile

7>Intel HD audio

8> 2X Seagate Momentus 7200Rpm
Sata2 HDDs (80GB X2)

9>HP DVD Writer/RAM with
Lightscribe

10>Inbuilt Bluetooth and Wi Fi, +

Dial-up Modem +100mb/s lan
11>Ports-
4X USB2
1X S-video and VGA
1X Firewire
1X PCM cia and Express card slot
5 iN 1 Card reader


Misc-

1>HP Quick play Buttons
and remote control

2>Copper Heatpipe cooling

3>Fullsize + Numeric keyboard

 

Um bhvm, please don't revive a year old thread when there is a "Undervolting" thread already on the front page!