Author

Topic: Save money! Underclock your cpu. (Read 1744 times)

legendary
Activity: 1512
Merit: 1036
July 04, 2011, 12:51:09 PM
#12
My kind of man. Are you pfsense, monowall or smoothwall?
None of the above. http://www.ipcop.org/
sr. member
Activity: 413
Merit: 250
July 04, 2011, 12:47:54 PM
#11

[Minimal Investment] I posted this becuase I'm sure a large majority of the miners didn't run out and buy all new equipment. I used leftover stuff to make my 2nd and 3rd mining rig. The few extra dollars I'll pay will surely not be more than a whole new board, cpu and psu over the course of a two years.

[Resell Value] If bitcoin tanks, or I go to prison, or whatever, it's much easier to sell a core 2 quad than a sempron.

[Bugs in the system] Mentioned in my originial post, I could not stop the miners from consuming 100% utilization on one core. The OS will not be dropping voltage and multiplier. It thinks the mining programs need it all.

This is just my situation, which others might be in, and tips for each other if we are.

That is a cool trick if you have a motherboard that can completely turn off cores. However, for those that are using their computer as a workstation, the extra cores won't be able to be used when they are needed, and idle cpu cores do still use only about 10% the power. For that dedicated mining rig, you could sell the Core 2 Quad and buy a half-dozen Celeron D's http://www.aztekcomputers.com/CEL2660D775R-INTEL-1859081.html; the most they can depreciate is $10, and that's if you throw them in the garbage.

On either chip, running them at a lower clock and voltage is a good trick. I have a firewall running an Athlon XP 1700 at 600MHz at 1.0V.

My kind of man. Are you pfsense, monowall or smoothwall?

And yea, I mean I totally get the pro's and cons. Not trying to sound too argumentative.

True about the cpu's at 21 for the first, plus 10 dollars each. That site charges horribly for shipping. I'm sure if I hunted on craigslist I could find something close.
legendary
Activity: 1512
Merit: 1036
July 04, 2011, 12:37:22 PM
#10

[Minimal Investment] I posted this becuase I'm sure a large majority of the miners didn't run out and buy all new equipment. I used leftover stuff to make my 2nd and 3rd mining rig. The few extra dollars I'll pay will surely not be more than a whole new board, cpu and psu over the course of a two years.

[Resell Value] If bitcoin tanks, or I go to prison, or whatever, it's much easier to sell a core 2 quad than a sempron.

[Bugs in the system] Mentioned in my originial post, I could not stop the miners from consuming 100% utilization on one core. The OS will not be dropping voltage and multiplier. It thinks the mining programs need it all.

This is just my situation, which others might be in, and tips for each other if we are.

That is a cool trick if you have a motherboard that can completely turn off cores. However, for those that are using their computer as a workstation, the extra cores won't be able to be used when they are needed, and idle cpu cores do still use only about 10% the power. For that dedicated mining rig, you could sell the Core 2 Quad and buy a half-dozen Celeron D's http://www.aztekcomputers.com/CEL2660D775R-INTEL-1859081.html; the most they can depreciate is $10, and that's if you throw them in the garbage.

On either chip, running them at a lower clock and voltage certainly works. I have a firewall running an Athlon XP 1700 at 600MHz at 1.0V.
sr. member
Activity: 413
Merit: 250
July 04, 2011, 12:01:12 PM
#9
That's why you build your mining rig with a low power CPU from the start, a good example would be an AMD Sempron 140, which I run in one of my rigs. While the maximum TDP is 45W, it automatically cuts the voltage and multiplier during low usage to enter a lower power state using AMD Cool 'n Quiet technology (set your Windows XP power profile to "portable/laptop" to fully enable it after installing the AMD CPU driver.) A running Windows 7 Sempron system draws 35 watts from the wall!: http://www.servethehome.com/amd-sempron-140-sargas-whs-review/.

The other factor is power supply efficiency. You need to look at the efficiency of the power supply at the actual wattage you will be drawing when mining. http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story2&reid=142 is a good site for finding real-world efficiency of power supplies at different power draws. The linked review is of an 850W power supply, but it is most efficient (85%) at around 519 watts (using 611 watts AC), and above that the efficiency goes down. I picked this power supply for you because 520 watts is about what a Sempron + 3x overclocked 6850s + 1GB slow DDR + a small HDD + fans would use while mining ( 20W + 3x160W + 20W ). Overclockability is enhanced because the +12V quality is higher when you aren't using your power supply at it's maximum. Now you have 480 watts of video cards running for 611 watts at the outlet, which is about as low as it can go!


[Minimal Investment] I posted this becuase I'm sure a large majority of the miners didn't run out and buy all new equipment. I used leftover stuff to make my 2nd and 3rd mining rig. The few extra dollars I'll pay will surely not be more than a whole new board, cpu and psu over the course of a two years.

[Resell Value] If bitcoin tanks, or I go to prison, or whatever, it's much easier to sell a core 2 quad than a sempron.

[Bugs in the system] Mentioned in my originial post, I could not stop the miners from consuming 100% utilization on one core. The OS will not be dropping voltage and multiplier. It thinks the mining programs need it all.

This is just my situation, which others might be in, and tips for each other if we are.
legendary
Activity: 1512
Merit: 1036
July 04, 2011, 10:47:09 AM
#8
That's why you build your mining rig with a low power CPU from the start, a good example would be an AMD Sempron 140, which I run in one of my rigs. While the maximum TDP is 45W, it automatically cuts the voltage and multiplier during low usage to enter a lower power state using AMD Cool 'n Quiet technology (set your Windows XP power profile to "portable/laptop" to fully enable it after installing the AMD CPU driver.) A running Windows 7 Sempron system draws 35 watts from the wall!: http://www.servethehome.com/amd-sempron-140-sargas-whs-review/.

The other factor is power supply efficiency. You need to look at the efficiency of the power supply at the actual wattage you will be drawing when mining. http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story2&reid=142 is a good site for finding real-world efficiency of power supplies at different power draws. The linked review is of an 850W power supply, but it is most efficient (85%) at around 519 watts (using 611 watts AC), and above that the efficiency goes down. I picked this power supply for you because 520 watts is about what a Sempron + 3x overclocked 6850s + 1GB slow DDR + a small HDD + fans would use while mining ( 20W + 3x160W + 20W ). Overclockability is enhanced because the +12V quality is higher when you aren't using your power supply at it's maximum. Now you have 480 watts of video cards running for 611 watts at the outlet, which is about as low as it can go!
sr. member
Activity: 413
Merit: 250
July 04, 2011, 09:23:14 AM
#7
Just did this thanks for the tip you saved me some power thats for sure.
To lazy to get the clamp meter out and check how much tho.

Should be able to calculate with the link in my OP. The website has a list for all the CPU's so you'll know what the starting voltage and mhz is.
sr. member
Activity: 294
Merit: 250
July 04, 2011, 09:17:05 AM
#6
Just did this thanks for the tip you saved me some power thats for sure.
To lazy to get the clamp meter out and check how much tho.
sr. member
Activity: 413
Merit: 250
July 04, 2011, 07:49:00 AM
#5
I heard that some people have checked their wattages and when they set CPU affinity to the one core, now easily done in GUIMiner, it reduces the entire power consumption of the computer by 0.1-0.2kWh! This could potentially save about $13 to $26/month for me (I pay 18c/kWh electricity). I will try underclocking as well.

Yea, I've been doing the affinity thing since before it was in GUIminer. An old trick I learned way back in the day playing Dark Age of Camelot. I added some info to my original post and a link that should help with this!
newbie
Activity: 38
Merit: 0
July 04, 2011, 07:45:46 AM
#4
I heard that some people have checked their wattages and when they set CPU affinity to the one core, now easily done in GUIMiner, it reduces the entire power consumption of the computer by 0.1-0.2kWh! This could potentially save about $13 to $26/month for me (I pay 18c/kWh electricity). I will try underclocking as well.
sr. member
Activity: 413
Merit: 250
July 04, 2011, 07:43:18 AM
#3
Mine downclocks in the BIOS when its doing fuck all - is this what you mean?
If "fuck all" means nothing, then yes.

But I just forced mine to run at lower speed from the get go. Especially seeing that with more than 1 card I still get the 100% cpu utilization on 1 core, no matter the speed. I've attempted to fix it, but it never worked and I gave up.
legendary
Activity: 1022
Merit: 1001
July 04, 2011, 07:33:11 AM
#2
Mine downclocks in the BIOS when its doing fuck all - is this what you mean?
sr. member
Activity: 413
Merit: 250
July 04, 2011, 07:31:44 AM
#1
I haven't read across anyone doing this, nor did I do a specific search.

If you are using a dedicated rig or want to restart before you do gaming, you should consider underclocking your rigs.
I have 3 dedicated miners. As example one is using an evga 780i sli, core 2 quad 6600, and 3x 6850's (got a killer deal on them, but they kinda suck).
With that board I could disable the last 3 cores. I then underclocked it to 1.6ghz (I might be able to go lower, but that was easy) and undervolted it. My hashing did not change. It's a little laggier to VNC into it but I'll put up with that.

Next I'm debating about lowering the bus speeds and ram. I'm only running a single one gig module of ram as it is.

While I might only be saving a buck or two a month, the guys who are running some serious hardware and 10 machines will get much more benefit out of this.

Update:
Here's a link to determine your old vs new wattage!
http://extreme.outervision.com/tools.jsp

I went from 95w to 41w with 2400/1.25v to 1600/1v!
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