Anyone actually bother to undervolt anymore?

~El~Jefe~ · Post by **~El~Jefe~** » Fri May 08, 2009 5:00 pm

oh. i have asus P5Q SE2

has a lot of options. shrug.

whiic · Post by **whiic** » Sun May 10, 2009 4:32 pm

I undervolt during summers. Not that I'm running my Q6600 G0 too hot but to save electricity.

Summer: 2.4 GHz (max), 1.6 GHz (typical), 1.1 vcore (constant, as it's lowest mobo can give). Vdroop modded to increase voltage stability. (Not good for undervoltability during summer.)

Winter: 3.2 GHz (max), 2.1 GHz (typical), 1.275 vcore (constant, as having variable voltage (that could be changed with RMClock) would require me to boot at mobo's suggested voltage 1.4+ volts or so before Windows boots and RMClock kicks in... don't want to toast it)

Why do I run high clock in the winter is because saving electricity during winter in a electically heated house is completely impossible. It functions as a household heater...

vdroop mod increased minimum voltage I could give to CPU during summer, but it did increase voltage stability during winter clocks. Without vdroop mod, my voltage would drop horribly at CPU load (4 cores at 3.15 GHz draws quite a bit of power, thus cause much vdroop), forcing me to compensate in BIOS voltage setting and causing high idle vcore. With droop mod, I actually have positive vdroop despite being set to constant voltage. Exactly how it should be.

___

Laptop is undervolted via RMClock utility only. No BIOS option. I couldn't lower the idle voltage (too bad, since it would have improved battery life) but I did manage to make Prime95 stable load vcore the same as idle vcore, the minimum supported voltage.

It has some instability when running from battery for prolonged periods of time at 100% CPU util. If I game it hard, it will bluescreen at roughly 40% remaining battery life. When running AC, I can game it all day without problems. Laptops aren't really intended for gaming... especially when running on battery. I do it anyway but I've learned not to run battery too dry to make it crash. It could be some miscalculation in remaining capacity as well. Sometime when system crashes at 30+% and I shut down the system to power it up later, it refuses to start as battery appears to have completely drained to 0%.

When idling, I get a battery life of around 6 hours or 7 hours. This is unaffected by undervolting as idle vcore is default.

~El~Jefe~ · Post by **~El~Jefe~** » Tue May 12, 2009 12:58 pm

I never thoguht about undervolting a laptop.

that's an interesting idea.

Nighthog · Post by **Nighthog** » Wed May 13, 2009 9:45 am

I undervolt my current computer to get less heat from it.

It has just turned 1 year old. It's a Phenom X4 9750 whit amd stock heatpipe cooler. Though it's on it's 3rd motherboard already.
On stock voltage 1.3v it gets just ridiculously hot in my setup. I have it set to 1.175v in bios which actually really gives about 1.168-1.184v in idle usage. But when the computer starts to crunch some hot stuff it starts to eat 1.200-1.216 volts. I have also undervolted the NB voltage to -0.025v if I remember the value correctly.
This gives me a cpu temp off MAX 60-61C in whatever situation currently.

Computer is rock solid stable now, I've tested it loads. Though I do get worried every time I start to smell barbecue when my room window is open as I think my computer has started to burn again.

(reason is the usage off a shit motherboards that could not handle the 9750 and got toasted(they were not capable off undervolting either so cpu did run at 1.35x-1.4xx volts(happy overvolters >_>;, they could not handle the load so gave happily automatically some extra juice adding to the disaster), I have a better motherboard these days but still that smell of something burnt gets me to panic shortly, I did manage to burn two GA-MA78GM-S2H motherboards... Never touching that specific piece of shit again.)

jurian89 · Post by **jurian89** » Thu May 14, 2009 8:30 am

I am planning to undervolt the upcoming AMD Phenom II X4 905e. I'll post the results here

shooty · Post by **shooty** » Mon May 18, 2009 12:51 pm

I have my AMD system undervolted.
the AMD PII 940 is undervolted by .1V to a max voltage of 1.25v.
CnC is still enabled and can bring it down to .85v @ 800mhz - I believe .85v is the lowest recommended voltage for this cpu.
My memory, g.skill ddr2 1066 5.5.5.15, is undervolted slightly to 2.04v.
and my NBcore is down by .05v to 1.25v.
this is on a DFI lanparty jr 790gx-m2rs.
The system runs very stable - not had any problems for a few months of heavy usage. I have a x1900xt gpu and I game on it but not too intensely.
reason for undervolting was to lower temps. I have all this stuff shoved into a mATX desktop case.

my previous s939 4200+ build would overheat when stressed in this case - this current system does not.

I've had this cpu undervolted and overclocked to 3.2 but CnC doesn't work when overclocked on this board so back to stock speeds.

BTW, HI ALL! - first post

Redzo · Post by **Redzo** » Mon May 18, 2009 1:02 pm

How about "No I don't" as an alternative ?

~El~Jefe~ · Post by **~El~Jefe~** » Fri May 22, 2009 9:37 am

denied.

LodeHacker · Post by **LodeHacker** » Fri May 22, 2009 12:06 pm

~El~Jefe~ wrote:denied.

Fail of the Year 2009 Award

Post by **Ralf Hutter** » Fri May 22, 2009 1:43 pm

~El~Jefe~ wrote:denied.

HA! "Denied" is for peons!

Edit by helpful, kind and good-looking moderator added this option. Now everyone truly has a choice!

crabnebula · Post by **crabnebula** » Sat May 23, 2009 7:32 pm

HTPC based on AMD 780G + Athlon X2 5000+ is deeply undervolted in BIOS. Runs passive 90% of the time.

Older laptop based on 1.5 GHz Pentium M is also undervolted with RMClock to prolong battery life and reduce heat/noise.

Desktop based on Core 2 Quad is left at stock voltages in BIOS with SpeedStep enabled and the FSB + Vcore are adjusted dynamically with the Asus EPU-6 Engine utility. This allows overclock under load and underclock/undervolt when idle.

It seems to me that in almost every application (HTPC, home server, laptop, etc.) it is a big plus to undervolt whenever possible.

~El~Jefe~ · Post by **~El~Jefe~** » Sat May 23, 2009 9:02 pm

I'm comming to the understanding that wolfdale and up cpu's in a gaming system probably isnt worth it.

Zenphic · Post by **Zenphic** » Sun May 24, 2009 7:53 am

I undervolt my two laptops (Intel Pentium M 1.86GHz on Compaq nc6220 and Intel T5750 on Dell Inspiron 1525) with RMClock.

CrystalCPUID works better on my AMD 5000+ BE with Gigabyte GA-MA78GM-S2H (rev 1.1). As for my other desktop (Intel E2160 on XFX 650i Ultra), undervolting through the bios gives me lower voltages than RMClock and CrystalCPUID.

Undervolting on Windows is simple. You just need time to stress your processor sufficiently (prime95 with SmallFFT or intelburntest) to make sure your PC is stable.

Shamgar · Post by **Shamgar** » Sun May 24, 2009 10:15 am

I recently built a system with AMD X2 4850e and 780G/SB700 chipset. Normal Vcore is ~1.25V. In BIOS I can get it down to 1.00 with no apparent problems. Dropping it further to 0.975 and the system fails to POST.

My Gigabyte GA-MA78G-DS3H board seems to want to give more voltage than whatever I select; it adds another ~0.015-0.025. It "overvolts" my RAM however from a stock 1.8 to 1.95. Is this standard practice for motherboards or Gigabyte in particular?

I'll keep this system undervolted as long as it's stable and there's no real negative effects. Runs cooler, quieter and uses less power. A lot to gain and not much to lose in my situation.

neumein · Post by **neumein** » Mon May 25, 2009 3:23 am

Don't mean to brag (too much

), but I've got my Q6600 both undervolted and overclocked. Curently running rock steady @ 3.2Ghz with 1.28v. Shop I bought it from says I'm the luckiest guy in the world. Considering my chip will also do 4.2Ghz on water. I couldn't agree more.

Post by **Ralf Hutter** » Mon May 25, 2009 6:00 am

Zenphic wrote:I undervolt my two laptops (Intel Pentium M 1.86GHz on Compaq nc6220 and Intel T5750 on Dell Inspiron 1525) with RMClock.

Undervolting on Windows is simple. You just need time to stress your processor sufficiently (prime95 with SmallFFT or intelburntest) to make sure your PC is stable.

What he said^

...except, substitute "a few IBM T42 Thinkpads" for the Compaq and Dell that he is referring to.

Also, substitute "Notebook Hardware Control" for RMClock.

Undervolting is the way to go on notebooks. They run cooler so the fans rarely, if ever, come on, this keeps them nice and quiet. They use less power so the battery life is longer, and they don't fry your legs if you're actually using them on your lap.

Thomas · Post by **Thomas** » Mon May 25, 2009 8:02 am

Shamgar wrote:I recently built a system with AMD X2 4850e and 780G/SB700 chipset. Normal Vcore is ~1.25V. In BIOS I can get it down to 1.00 with no apparent problems. Dropping it further to 0.975 and the system fails to POST.

The above is excatly why I dont bother undervolting... C'n'Q gives me 1,00 volt automatically !!!

80-90% of the time, my system is at idle. Further, it's only on for approx. 4 hours a day, average.

If I'm lucky, I might lower the idle wattage by a few watts by undervolting... But having the system on 3 x 24 hours @ full load to ensure stability and to find my systems limits, will result in a lot's of watts wasted... Around 10 kWh... If I save 2 watt @ idle, it would take me approx. 3,5 year, to gain those 10 kWh back...

I see the point with older systems, which dont have C'n'Q, but my previous socket A system, didnt support undervolting

xen · Post by **xen** » Wed May 27, 2009 7:10 pm

If I save 2 watt @ idle, it would take me approx. 3,5 year, to gain those 10 kWh back...

Now there's an intelligent remark! However, 3.5 years seems long, but I'm planning to use my new computer for at least 10 years, unless i kill it again. My current computer has been in use since 2001. We are reaching (have reached) the point where performance upgrades are useless for the average (non-gaming) customer.

The only reason any normal computer user has to upgrade, is because Microsoft is abusing its monopoly by fasing out a still popular product (Windows XP).

Shamsham wrote:My Gigabyte GA-MA78G-DS3H board seems to want to give more voltage than whatever I select; it adds another ~0.015-0.025. It "overvolts" my RAM however from a stock 1.8 to 1.95. Is this standard practice for motherboards or Gigabyte in particular?

I remember reading something like that about these boards! I don't think it's standard for boards in general. I'm looking to purchase the GA-MA78GM-UD2H and I consider it likely that it will exhibit the same behaviour.

merlin · Post by **merlin** » Mon Jun 01, 2009 3:21 pm

Thomas wrote:
Shamgar wrote:I recently built a system with AMD X2 4850e and 780G/SB700 chipset. Normal Vcore is ~1.25V. In BIOS I can get it down to 1.00 with no apparent problems. Dropping it further to 0.975 and the system fails to POST.
The above is excatly why I dont bother undervolting... C'n'Q gives me 1,00 volt automatically !!!

80-90% of the time, my system is at idle. Further, it's only on for approx. 4 hours a day, average.

If I'm lucky, I might lower the idle wattage by a few watts by undervolting... But having the system on 3 x 24 hours @ full load to ensure stability and to find my systems limits, will result in a lot's of watts wasted... Around 10 kWh... If I save 2 watt @ idle, it would take me approx. 3,5 year, to gain those 10 kWh back...

I see the point with older systems, which dont have C'n'Q, but my previous socket A system, didnt support undervolting

I should mention one thing. My concern is far more about load heat/noise increases than power savings. I know the amount I save is pretty minimal and not going to change my life. I lose many times more money just from the stock market than any type of power savings. My goal of undervolting is to decrease temperature increases as much as possible. C'n'Q and similar mechanisms do not help at load at all. Also undervolting directly still does help with idle power, just possibly not as much as automatic idle voltage droppers. Another thing to note is that I generally turn off my computer every night...therefore idling isn't quite so important for me.

Vibrator · Post by **Vibrator** » Sat Jun 06, 2009 12:15 pm

I say I do, but I'm lying.

I'm on stock voltage. (1.325v)

doveman · Post by **doveman** » Sun Jun 07, 2009 2:45 am

Shamgar wrote:My Gigabyte GA-MA78G-DS3H board seems to want to give more voltage than whatever I select; it adds another ~0.015-0.025. It "overvolts" my RAM however from a stock 1.8 to 1.95. Is this standard practice for motherboards or Gigabyte in particular?

Yeah, my GA-MA780G-UD3H provides the same Vcore to my PhII 720BE on Auto as at the manual +0.075v setting (1.39v). It also pumps 1.95v to my RAM and annoyingly, unlike with the Vcore, there's no way to reduce this.

plympton · Post by **plympton** » Sun Jun 07, 2009 7:33 am

Just popped in a Banias 1.7 GHz Pentium M into my wife's old Presario laptop - it had a Celeron M 1.4 GHz that was always revving the fan since it doesn't have SpeedStep - really annoying.

Got a Banias for $20 shipped off eBay, brand new, undervolted with RMClock at .7v @ 600 MHz, an 1.084 @ 1.7 GHz - a full .25v undervolt. Runs nice a cool now - the fan hardly ever comes on now.

So yeah, undervolting is cool...

-Dan

doveman · Post by **doveman** » Mon Jun 08, 2009 4:46 am

Forgot to say, yes I do undervolt and I love it!

With my PhII 720 on about 1.15v, it runs substantially cooler at idle and load than at the (Gigabyte) default 1.39v. I'm currently running overclocked and undervolted at 3.2Ghz on 1.28v.

I've posted the temperatures measured at various settings here if anyone wants to have a look.

theycallmebruce · Post by **theycallmebruce** » Mon Jun 08, 2009 6:54 pm

I've started running a mild undervolt

and underclock

on my AMD 4800+ just to keep the temps down when I'm gaming. If I run the stock voltage and clock speed, temps spiral up until it locks in games. Still in the process of tuning it.. I'm hoping I can undervolt some more and get back up to stock clock.

I have a couple of questions and worries inspired by this thread though.

1) In general, how does power consumption vary with clock speed and voltage? Is the formula P=I * V^2 correct for voltage? How about for clock speed?

2) Nighthog, I have the exact board you burned out - the MA78GM-S2H. Now I'm a bit worried! When you say yours couldn't undervolt, do you mean the BIOS didn't have an option (mine does) or that the system burned out when undervolted? My 4800+ should chew a lot less juice than the 9750.. but I was thinking about a CPU upgrade in the future, so you have me a bit worried.

Vibrator · Post by **Vibrator** » Mon Jun 08, 2009 8:10 pm

Shamgar wrote:I recently built a system with AMD X2 4850e and 780G/SB700 chipset. Normal Vcore is ~1.25V. In BIOS I can get it down to 1.00 with no apparent problems. Dropping it further to 0.975 and the system fails to POST.

My Gigabyte GA-MA78G-DS3H board seems to want to give more voltage than whatever I select; it adds another ~0.015-0.025. It "overvolts" my RAM however from a stock 1.8 to 1.95. Is this standard practice for motherboards or Gigabyte in particular?

I'll keep this system undervolted as long as it's stable and there's no real negative effects. Runs cooler, quieter and uses less power. A lot to gain and not much to lose in my situation.

I have the same board

For some reason it doesn't boot with dual channel memory, only single channel -.-

Nighthog · Post by **Nighthog** » Wed Jun 10, 2009 8:00 am

theycallmebruce wrote: 2) Nighthog, I have the exact board you burned out - the MA78GM-S2H. Now I'm a bit worried! When you say yours couldn't undervolt, do you mean the BIOS didn't have an option (mine does) or that the system burned out when undervolted? My 4800+ should chew a lot less juice than the 9750.. but I was thinking about a CPU upgrade in the future, so you have me a bit worried.

The GA-MA78GM-S2H didn't allow for Phenom undervolting in BIOS, you either had the stock 1.3volts or MORE! and even whit 1.3v stock it overvolted for no reason >_>;

Athlon cpu:s I've seen mentioned have no problem having options for undervolting in the BIOS. Problem only concerned the phenom cpu's whit the rev 1.0 & 1.1 boards. I have no idea how rev 2.x does or if support has been added whit later bioses since I changed my board for another one.

--------------
To update my undervolting adventures thanks to the find off K10STAT I now use it to regulate my Cpu frequency and voltages.
My Phenom X4 9750 now runs at 1.0Ghz @ 0.816v in idle usage (less than 25% cpu usage at 2.4Ghz circumstances)and under larger load it increases to the normal 2.4Ghz @ 1.168-1-184v (meaning it goes back to 2.4Ghz when 1.0Ghz reaches 80% cpu usage on any core)

Anyone actually bother to undervolt anymore?

Anyone actually bother to undervolt anymore?

Undervolting == Yes!