Why do the EE versions of the AMD X2's use less energy at full load?

[Smartazz]

Is there anything truly different between the EE (65watt) X2 3800+ and the regular X2 3800+(89watts) other than the voltage? Is that what makes the difference in wattage, 1.3volts vs. 1.2volts.

 

[StrangerGuy]

Heat output and power consumption of a CPU increases to the square of the voltage increase...Simply put, a minor 0.1V difference means a significant power draw difference.

 

[Smartazz]

Originally posted by: StrangerGuy
Heat output and power consumption of a CPU increases to the square of the voltage increase...Simply put, a minor 0.1V difference means a significant power draw difference.

So there's no different between these two CPUs other than that?

 

[Khyron320]

Nope if you can get your 3800 to run at the same voltage you should get the same result

 

[lopri]

It's probably just a natural byproduct of binning process. Just like some chips overclock better, some chips can run with less voltages. Since there is a market for low-power parts, why not make SKUs for those who seek them? Performance-wise, they should equal under same frequency.

 

[Idontcare]

Originally posted by: Smartazz

Originally posted by: StrangerGuy
Heat output and power consumption of a CPU increases to the square of the voltage increase...Simply put, a minor 0.1V difference means a significant power draw difference.

So there's no different between these two CPUs other than that?

Well of course there is a difference, the lower voltage chip can run at volts lower than the higher voltage one, but the question you are probably asking is whether or not their is an intentional difference (i.e. circuit layout, pin-outs, or intentional process tweaking during manufacturing) to which Lopri effectively answered the question - i.e. nothing is done to intentionally create EE chips.

But make no mistake that the EE chips are different, just not intentionally different. Process variations will naturally generate a distribution of parts that can run at higher frequencies on lower wasted heat output and lower voltage. Might be variations in implant, in photo CD of the gate, or even the via resistance at any given metal level in the BEOL.

 

[myocardia]

Originally posted by: Smartazz
So there's no different between these two CPUs other than that?

Like lopri and idontcare already said, there's no difference at stock speeds. Don't you overclock your 3800, though? If so, everyone who has bought one says that the EE's don't overclock well at all, compared to the 89 watt X2 3800's.

 

[Jhhnn]

That's 35 watts, not 65 watts-

http://www.amdcompare.com/us-en/desktop/details.aspx?opn=ADD3800IAT5CU

A huge difference in power consumption and cooling requirements... ~3X the price, however...

 

[Smartazz]

Originally posted by: Jhhnn
That's 35 watts, not 65 watts-

http://www.amdcompare.com/us-en/desktop/details.aspx?opn=ADD3800IAT5CU

A huge difference in power consumption and cooling requirements... ~3X the price, however...

There's actually three variations. The 35 watt chip is the SFF one. There's:
89watts:1.3volts
65watts:1.2volts
35watts:1.025volts

 

[shamans]

what volts do the 35W ones run at while idle with cool n quiet?

I know my 89W one runs at 1.4 V @ load and 1.1 V @ idle (by default).

 

[Smartazz]

Originally posted by: shamans
what volts do the 35W ones run at while idle with cool n quiet?

I know my 89W one runs at 1.4 V @ load and 1.1 V @ idle (by default).

I wonder how low they can go. BTW, is cool n quiet worth using, does it slow down performance at all?

 

[TanisHalfElven]

Originally posted by: Smartazz

Originally posted by: shamans
what volts do the 35W ones run at while idle with cool n quiet?

I know my 89W one runs at 1.4 V @ load and 1.1 V @ idle (by default).

I wonder how low they can go. BTW, is cool n quiet worth using, does it slow down performance at all?

use rmclock. far better than cool and quite alone.

 

[Smartazz]

Originally posted by: tanishalfelven

Originally posted by: Smartazz

Originally posted by: shamans
what volts do the 35W ones run at while idle with cool n quiet?

I know my 89W one runs at 1.4 V @ load and 1.1 V @ idle (by default).

I wonder how low they can go. BTW, is cool n quiet worth using, does it slow down performance at all?

use rmclock. far better than cool and quite alone.

Wow, this program is great. Thanks for the info.