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AMD Beats Intel in Power-Efficiency Study
Ted Samson writes "AMD Opteron servers proved up to 15.2 percent more energy-efficient than those running Intel Xeon in a server-power-efficiency test performed by Neal Nelson and Associates, InfoWorld reports. That translates to annual electricity savings between $20.29 per server and $36.04 per server, depending on the workload, the study concluded. The benchmark tests were conducted on similarly configured 3GHz systems running Novell SUSE Linux, Apache2, and MySQL."
If you read the 6th paragraph of the article, AMD wasn't aware of this test, according to "John Fruehe, manager of worldwide market development for server/workstation products at AMD"
Equine Mammals Are Considerably Smaller
however differing power supplies do have different efficiencies of conversion. So we're really comparing top-to bottom solutions, and the processor may actually be a small part of the energy savings.
Always going forward, 'cause we can't find reverse.
Actually the power capacity of a supply WILL affect the power measured as even same amount of power output will be on different part of the efficiency curves even if component losses are identical. Power supplies tends to be most efficient from 1/3 to 2/3 of their power ratings.
For a more scientific study, they should use the same power supply.
IANAEE but I found this thing (pdf) from DELL that has a "typical" efficiency curve (fig A, on the third page of the pdf, page # 64) that shows efficiency is pretty flat from 35% up to max load. Within maybe 5%.
Equine Mammals Are Considerably Smaller
Anandtech recently did that kind of power efficiency vs. performance test actually: (2.6Ghz vs. 2.33ghz), with AMD coming out on top: http://www.anandtech.com/IT/showdoc.aspx?i=3039
We see similar when we build systems.
The Intel CPUs are competitive with the Opterons on power consumption.
But: The whole system uses more with Intel.
Why? the northbridge memory controller is a separate chip with Intel, and it is very power hungry.
In the AMD chips the memory controller is a part of the CPU.
In the case of a similar dual XEON compared to a dual Opteron,
the XEON machine uses about 80W more power.
What a lot of these studies do not even get into is cooling cost.
for every watt of power , which ends up heat, we have to expend at least 1.5 watts, on air conditioning.
As for the comment about the size of the power supplies, that is irrelevant.
The maximum rated output of a supply has nothing to do with the power consumed.
Bottom line:
Assuming an Intel XEON server uses about 80 watts more than an equivalent AMD one,
which is what we see when we build them:
80w x 24 hours/day x 365 days is 700KWh. @ 9c/kWh costs $63/year.
Add aircon costs for that extra 80W:
120w x 24 hours/day x 365 days is 1050KWh. @ 9c/kWh costs $96/year.
Therefore, a machine using an extra 80W costs an extra $160 to run in an air conditioned room.
Source of power rates:
http://www.neo.ne.gov/statshtml/115.htm
Maurice W. Hilarius Voice: (778) 347-9907
I'd like to know why they compared a Woodcrest Xeon, circa June 2006 to the latest and greatest Opteron of today.
I just want you to know...
That Page is over 4 years old..
*sigh*
Except for those of with HP/Compaqs with Semprons/Athlon64s who's internal timer runs twice as fast as it should, with no variety of kernel boot options alleivating the problem. Quite annoying. I know it's probably a problem in the motherboard not working correctly with linux, but still.
Did I get something wrong or just calculate with horribly over-efficient air conditioning?
There are so many questions to answer for this question that the real and true answer will never be known.
AMD runs better with no load, where Intel runs better with full load. So in this particular instance, do you have a server that's gonna idle 99% of the time(If so why are you not using a VMWare setup?) I'd expect a nice new server to be cranking out 100% usage for as long as I can keep it there.
You are correct that for every 1 watt of heat, it takes 1.5 watts(or sometimes even more) to remove the heat.... BUT the power supply is also relevant for 3 reasons:
1 The power supply does 'expend' energy that is basically lost(as heat).
2. This heat must be factored into the heat generation if you are taking into account the cooling.
3. Every power supply has it's own power efficiency curve. And size does matter(ladies?). I'll use 2 Seasonic's as examples because I own one myself:
-500W http://www.80plus.org/manu/psu/documents/Seasonic_ SS-500ET_500W_80PLUS_Report.pdf
-650W http://www.80plus.org/manu/psu/documents/Seasonic_ SS-650HT_650W_80PLUS_Report.pdf
Notice the most efficient curve peaks at roughly 50%. That means that if you are looking for pure efficiency, you need to know how much power your machine uses(at the outlet of the power supply) to determine how to make your system as efficient as possible. The 15-20% loss is mostly I(squared)R losses(heat loss). So you see size does matter. It may matter for 13% heat at 250W or 19% heat at 600W, but it DOES matter. The only true way to compare is to show watts consumed at the output of your power supply, not the input. If I were building a system for efficiency, I'll match my own power supply to my loading requirements.
The other thing to check out is performance and component cost. If your server is gonna be run at 100%(ideally your IT budget prefers this because you're maximizing your $), the Intel may be able to service more 'customers' at the same time than AMD.
Here's a hypothetical scenario:
I'm setting up project D. Project D will have to supply 10,000 customers simultaneously 24x7. I'm a big company and those server will actually have 10,000 customers serviced 24x7(this is only to provide static loading).
If I buy Intel servers I'll need 100 machines.
If I buy AMD servers I'll need 200 machines.
So if my Intel servers use 80W more power than AMD:
Intel Watts Total = 100 machines x watts used
AMD Watts Total = 200 machines x watts used
You could also say: Intel Watts Total = 100 machines x (AMD watts for 1 machine + 80W)
So if you need 100 Intel servers that draw an extra 80W of power each to service your 10,000 customers, but you need 200 AMD servers to service the same customers, which becomes more efficient? Suddenly your buying twice as many machines(so posibly higher startup costs for AMD), and I'm sure each of those AMD machines will draw more than 80W for each machine(remember the different between the AMD and Intel in my scenario is Intel is 2x more powerful for only 80W, so 2 AMD machines should be able to do the same work for cost of 1xAMD Watts + 80W to stay even with Intel for efficiency). But now you have twice as many systems that can fail, they are all highly loaded(which leans in intel's favor), more IT support will be required for those machines, more cooling for those extra machines, more space in a building somewhere(assuming you have the actual space), etc...
So, which setup was more efficient? In this case, Intel was. But if AMD's machines only drew 5 watts of power at full load, and their machines were 1/2 the cost, then maybe they'd be a better bet. I don't know about other people, but space in my building is at a premium. You can theoretically buy an infinite number of computers,