30w idle athlon II x2 240 rig

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greenfrank
Posts: 101
Joined: Sat Jan 17, 2009 2:32 pm
Location: Mexico

30w idle athlon II x2 240 rig

Post by greenfrank » Fri Mar 26, 2010 3:42 pm

I've just finished my new main pc. I use it mainly for office, web browsing/downloading, play music, video encoding, burn dvds, retouch photos. No games.

My goal was to have a powerful pc wiht a low power consumption (to "stay green" and save the bills). Previously I had an atom 330 rig but atoms are just too weak for some task, expecially image editing and video encoding.

In choosing the components, I did focus on price and low-power specs. I decided to go AMD, because of low price and good reviews for the Athlon II here in Silentpcreview. I was surprised for the very frugal consumption of this rig, with a little undervolting.

This is the pc I made, and some tests:

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*update. A closer wiew to the MoBo with the Picopsu 120-WI.
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The first step was with a "standard" non-80+ psu. After some days I swapped the psu for a picopsu 120-wi. I measured the power consumption with kill-a-watt.

CPU: ATHLON II 240 "REGOR" 2800MHz - Motherboard: Gigabye 785g (GA-MA785GM-US2H) / 2gb kingston DDR2 667 ram / HDD: 2.5" 250gb Fujitsu / DVD-RW samsung

OS: Windows XP Sp3

cool'n quiet: on
easysaver: on (maximum saving settings)
K10stat: on

cpu / northbridge chipset undervolted (k10stat/Easytune6): minimum cpu voltage: 0.7 / minimum NB voltage: 0.98
no underclock

[first step: psu: 500w generic (low efficiency)]

IDLE power consumption: 40w

MODERATE load (browser/office/Wmp on): 42-45w

HIGH load - prime95: 56w / Orthos: 59w

cpu temperature (moerate load): 25º C

noise: medium (psu fan + cpu fan on)

cpu fan: 1600-1800 rpm


[second step: swap psu to picopsu 120-wi + 120w-18.5v powerbrick]

IDLE power consumption: 30w [*if no program loaded, idle is 27-28w]

MODERATE load (browser/office/Wmp on): 32-35w

HIG load: prime95: 45w / Orthos: 45w

cpu temperature (moderate load): 26º C (after a while temp rise up to 29; the other sensors on the MoBo shows 32º, 39º and 47º C; after some hours cpu temp stay below 30º and mobo sensors all below 50º)

noise: inaudible (only cpu fan on)

cpu fan: 1600-2000 rpm *the stock amd fan has very low noise only if below 2000 rpm, then become a bit noisy.

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*update 29/03/2010
some considerations:
1 - Athlon II x2 is a very efficient Cpu, working well and cool at low voltages.
2 - This kind of rig has an idle power consumption similar to an Atom330 but can perform a way better, finishing tasks (as video enconding, photo editing) in less time. So, probably, it will consumes less energy (I did not do yet more accurate measurements).
Doing web surfing or office tasks (word, excel) stay at an average 30-34w power consumption level.

update 8/04/2010: these are the lowest p-states I've tested:
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at these voltages, there are no more gains in wattage, but the temperature stay very low, 18-24 ºC (rarely above 25), depending of room temp.
Last edited by greenfrank on Thu Apr 08, 2010 6:29 pm, edited 6 times in total.

kubunteando
Posts: 5
Joined: Thu Jan 21, 2010 6:50 am
Location: Helsinki

Good design and good try

Post by kubunteando » Sun Mar 28, 2010 10:10 am

Good system the one you have bulit.

I built a similar one end of last year.
I got a Gigabyte GMT-UD2H which is the same as yours but with DDR3 memory.
And an Athlon II 605e, a quadcore at 2.3GHz with also 45W TDP.
I added also an ATI HD 4550 for some gaming.

Total system consumption measured at the power plug of 42W at idle.
I did not use CPU undervolting yet because the mother board does not support it with CnQ enabled. And I use mainly Linux and the Linux undervolting utilities do not support yet my CPU.

The PSU is very important I also use a 120W PicoPSU.
The AC power adapter is important too. Which one do you use?
Mine came with the case and it gets very hot even at idle. I suspect it wastes at least 5 watts. I have found this one: FSP NB L90

With 87% efficiency. But still is not sold in Europe.



We should also tell about the motherboards good for undervolting.
The Gigabyte 785GMT-UD2H is not that good because with CnQ enabled it always sets the same voltage for the 800Mhz idle frequency.

Keep the info flowing. I am very interested in this topic.
Powerful computers even for some gaming but with as little as possible idle consumption.

greenfrank
Posts: 101
Joined: Sat Jan 17, 2009 2:32 pm
Location: Mexico

Post by greenfrank » Sun Mar 28, 2010 10:54 am

hi kubunteando,

your rig actually has a good power consumption because you have a dedicated graphic card. 42w is not bad at all. Probably what helps you is the "e" of your cpu (with a lower TDP than mine: the regor 240 has 65w).

I'm not an expert in undervolting. I just did experiments with k10 stat, and it worked like a charm, without turning of cool'n quiet in bios.

Yes, the psu is very important. As you can see, swapping a "traditional" psu for a picopsu dropped 10w the power consumption. The power brick probably in not that important, I tried with two: a 120w 18.5v power brick from an old HP laptop I have; and a multi-voltage 90w power brick for laptops, setted at 15v. I did not noticed any significative variation in power consumption.
In choosing the brick, I would pay attention in maximum capacity in watts, because athlon IIs peaks just below 100w at startup, before to stabilize at low wattages. You can't use a 60w power brick, I guess, even if your consumption is 30w to 45w.
For the sake of safety I will stay with the 120w power brick.
I'dont know how to measure the efficiency of these bricks (other than touch them to see if they get too hot), but I don't have plans to buy an extra expensive ultra-efficient one. Will be fine with the bricks I have.

[update: one of the bricks I'm using to test the rig. 90w multi-voltage brick for laptops.
Don't get hot, only warm, but I will feel better with the 120w brick.]
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I agree with you: the goal is to have the lower possible idle consumption, with the best performance doing intensive tasks.

I will continue to monitor the behaviour and the performance of my rig and update this post.
Last edited by greenfrank on Sun Mar 28, 2010 11:39 am, edited 1 time in total.

kubunteando
Posts: 5
Joined: Thu Jan 21, 2010 6:50 am
Location: Helsinki

Post by kubunteando » Sun Mar 28, 2010 11:14 am

I am using a 90W power brick, even the Pico PSU is 120W.
No issues during booting or intensive gaming, as you say most probably because of the 45W TDP; even I am using a dedicated graphic card.

I have also 2 bricks, and one is a bit less efficient than the other.

To measure the efficiency of the power brick (if it is not included in the specs) the only way is to measure both: the AC power consumption and the DC power consumption received by the Pico PSU. But that needs an additional device to measure it.

Please do report if you get any progress. I will do the same.

zodaex
Posts: 86
Joined: Wed May 21, 2008 9:16 pm
Location: Texas

Post by zodaex » Thu May 06, 2010 6:49 pm

That is amazing.

yuu
Posts: 132
Joined: Sun Aug 26, 2007 5:03 pm
Location: eu

Post by yuu » Mon Jun 07, 2010 4:39 pm

The Fortron 300EP being - 81 watts and 450VX - 85 watts idle on my system ~ 85% and 81% eff.

Chose using the 300EP for the lower power antique ~ 25W AC (HDD standby), 23.5 W AC (Hdd Off). 39.5 W Furmark.

HDD Deskstar 30GB ~ -4.5 W Standby -6.0 W Off
CPU Sempron E3 2500+ 1400Mhz pinmod 1.040 V - 90nm
MBD Nforce 6100-405
DDR 512MB DDR
DVD-RW ASUS1814ST

~19 watt DC / 25 AC measured,

Some made-up eff. to help me understand this.

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Even if the brick is 92% eff wich it isn't probably. still 4 watts less than regualar 20$ PSu, so much for power saving and bricks.

Help me see this in a better angle. except for being tiny.

ntavlas
Posts: 811
Joined: Mon Jul 16, 2007 2:35 pm
Location: Greece
Contact:

Post by ntavlas » Mon Jun 07, 2010 5:26 pm

Well, if the total power draw is low (25-30watts) a 10 or 15% improvement in efficiency isn`t going to be much is it?
I think the main advantage of a pico psu compared to a good 80plus psu with a low rating is the smaller size and the fact that it needs no fan.

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