AMD CPU Power Consumption

[pras1011]

I have a AMD 245 Athlon 2 CPU with 12 hdds.

 

When they are all spun down the total power consumption is 90 watts which too high.

 

Would switching to a lower powered CPU like a 170u be ok?

 

 

[bubbaQ]

The FIRST place to save power is get a 80+ Gold or better rated PSU.... and get the proper size.... many people get way too big a PSU.

 

The second, is your mobo.  The rage of power draw from the exact same CPU on different mobos is very wide.

 

Third, undervolt and undeclock your existing system.

 

I would not move to a different CPU until I had tried all of that first.

[pras1011]

I have a Corsair TX 650 which I think is a 80+ Bronze. I have a M4A89GTD USB3/PRO motherboard. How do I undervolt/underclock?

[bcbgboy13]

I have a AMD 245 Athlon 2 CPU with 12 hdds.

When they are all spun down the total power consumption is 90 watts which too high.

Would switching to a lower powered CPU like a 170u be ok?

 

I have a Corsair TX 650 which I think is a 80+ Bronze

 

You will have to determine your needs first - are you going to stay with 12 HDs (because of case limitations etc.) or not.

If you do stay with 12 HDs max then the 650W PSU is simply too powerful and you can safely move to 430W (and even less if available).

 

You have to rate your PSU to provide enough power for all the HDs running simultaneously -power up, data rebuild, parity checks but also if possible to be above the 20% of the PSU rated wattage when your system is idling as under this 20% loading threshold the efficiency usually drops significantly - down to 70 and even 60%...

 

Take a good look on your cooling solutions too- any 120mm fan will consume 2-3W when running (and more if it is power monster). In a typical CM590 case with 12 HDs you will have 3 fans on the front, two on the top, one back, PSU fan and the CPU fan - these fans if running at full speed are easily taking 12-20 Watts.

 

And for example I also have AMD-based DDR2 system as they are great for their build-in ECC support. I have 10 HDs (one of them 3TB) and without any extra modifications (I have all these fans running) and using a 45W TDP 4850e CPU my idling power usage is:

- 59 Watts with Corsair 430

- was 74 Watts with PCPQ 610W (I may have had one extra controller inside at that time)

 

Also a property selected motherboard is a must and that usually means do not buy an enthusiastic grade motherboard that will support any CPU and have all the bells and whistles (they still consume power if not used). For the AMD boards look for one that will support only up to 90-100W CPUs - in this way you will get some less power phases that in turn will decrease the power losses in low power (idling state). Added advantage on these boards is that they are also significantly cheaper.

 

And for some PSU recommendations and if money is not the limiting factor take a good look at this:

 

400 W fanless - for $90 after MIR - http://www.newegg.com/Product/Product.aspx?Item=N82E16817151097 - that will be ideal for your system.

 

500W fanless - this one apparently is very sophisticated (can shift the power where is needed) and apparently can power up to 20 green drives even been only 500W. - http://www.newegg.com/Product/Product.aspx?Item=N82E16817121083

[pras1011]

My case has 20 bays but I will probably use a maxium of 15 drives only. All of my fans are the silent low speed type. Unfortunately the motherboard and PSU are to well embedded within the case and the inital cost off these items where high. So I not be able to change them.