In Tests Opteron Shows Efficiency Edge Over Intel, Again

Ted Samson writes "In their latest round of energy-efficiency tests between AMD Opteron and Intel Xeon, independent testing firm Neal Nelson and Associates find AMD still holds an edge, but it's certainly not cut-and-dried. Nelson put similarly equipped servers through another gauntlet of tests, swapping in different amounts of memory and varying transaction loads. In the end, he found that the more memory he installed on the servers, the better the Opteron performed compared to the Xeon. Additionally, at maximum throughput, the Intel system fared better, power-efficiency-wise, by 5.0 to 5.5 percent for calculation intensive workloads. For disk I/O intensive workloads, AMD delivered better power efficiency by 18.4 to 18.6 percent. And in idle states — that is, when servers were waiting for their next work load — AMD consistently creamed Intel."

No matter....

[hurting now]

Even if its not cut and dry, this is EXCELLENT for the CPU industry. We need to see competition between the manufacturers.

Don't let that get lost in the arguments between which is better or what have you. Continued improvements and development benefits everyone.

Re:Efficient Post!

[Ajehals]

Idle power consumption may not be important for systems that are under a constant workload all the time, but for office file servers, where any given server may be under heavy load for 8 hours a day (probably closer to 6 and probably not "heavy load at that), having it draw less power in the remaining 16 hours would be rather beneficial, after all a server like that would be idle 2/3 of the time.

Obviously ideally you would be using all your kit at 95% capacity all the time, but even then you would need some idle kit stood by to take case of any additional demand. Sadly company' who aren't planning their IT systems with load in mind (but rather by which vendor takes them to lunch more often or which has the coolest flashing lights) are probably not too interested in power consumption stats anyway

Re:Efficient Post!

[Bert64]

Most servers spend a lot of time idle, often far more time idle than busy...
You don't buy a server that is just barely fast enough for your workload, your over-spec so that it can easily handle spikes in load and allow for future growth.
Also, many business operations have busy hours and quiet hours, for instance internal servers at a company will usually only see much load during working hours.

sort of useless

[krog]

Only a fool would specify an Opteron or a Xeon in a power-critical application. You might as well compare fuel consumption among a group of muscle cars; the very act of comparison indicates that you missed the point entirely.

Re:sort of useless

[Applekid]

Depends on the rest of the specs. If you have a muscle car with more power for less fuel, certainly it's worth noting.

Tests show xeon performs equal to opteron

[edxwelch]

Actually, if you look at the raw test data (rather than the conclusions) you will see that both servers performed nearly equally. The xeon doing slightly better on some tests, while the opteron better in others. In most tests the results are about the same (5% difference)

Can we actually see the damn test config

[arivanov]

Amazingly skimpy article. No effing data whatsoever.

I can bet a case of beer that this was run in a standard server config under Winhoze Server 2003. These are the results you more or less expect in that case.

If that is the case neither Opteron, nor Xeon utilise CPU frequency scaling as there is no OS support. If you use CPU frequency scaling under let's say current RHEL or Debian, the idle and IO efficiency picture tends to reverse because AMD is still not as good at this as Intel. In fact it not even supported on many server BIOSes/Motherboards.

As a result even if supported (and it usually isn't) AMD power utilisation with reduced frequency in idle is higher than that of a Xeon system which consumes nearly nothing when you slam it down to 250MHz. If the OS drops and ramps up the CPU frequency correctly Intel should win on idle and IO-only benchmarks.

Not that it matters in the slightest as AMD will cream it on most real life loads anyway due to better memory and IO bandwidth.

Depends on the kind of server

[Sycraft-fu]

A file server or webserver doing static pages, sure. A computation server or server doing lots of dynamic content, not so much. A more useful benchmark would be to measure the actual loads for various tasks, then see how they perform for that. Say "If you have a server doing X, this is what you can expect form these processors." Servers aren't a "one size fits all" kind of deal. I agree idle efficiency is something worth considering but let's not pretend like all servers just idle. Also, I know many places are like us in that the more a server idles, the older the server that tends to go there. We don't have much acting as your LDAP servers, but then we don't need it. However our computation servers are rather powerful, and loaded almost 24 hours a day.

Re:sort of useless

[Wesley Felter]

The point of the study is the relative power efficiency of the two processors, not absolute power efficiency. If you need the performance of an Opteron or Xeon, why wouldn't you choose the more efficient one (all else being equal)?

Re:sort of useless

[geekoid]

Nope. Muscle cars are about power. If you car has more power and less fuel, you win. If your car has more power and more fuel, then you win.
It's not even worth noting.
Now if you are talking about high performance race cars, then it is pretty important.

Performance per watt per...

[SanityInAnarchy]

It's all about performance per watt. Well, and other considerations, like how much the hardware costs up front, and how much physical space it will require.

The bottom line is: You want to spend your money in the most efficient way possible.

If you have two potential architectures, and one offers more performance per watt, then ignoring up front hardware costs, it's cheaper to run the one that costs you less power. That's a bit different than suggesting they just use a bunch of laptop CPUs.

Mod back up

[Wesley Felter]

I don't fully agree with the parent post, but it's not a troll. Some of these are legitimate issues.

there's no discussion as to the optimizations made to the software being run on each of the boxes. Is the code compiled for each architecture individually taking into account support for 3DNow / SSE instructions, cache sizes, etc? Obviously more efficient or less efficient code execution would have a MAJOR impact on these studies, enough so that companies usually spend a large amount of time playing with compiler options to get the best performance on a given architecture.

In the real world, people use the binaries that are provided by the distro, which is also what was done in this test. Apache and MySQL are not particularly amenable to compiler optimization anyway.

Nope...

[Colin Smith]

It's the people buying the things they are appealing to. It's your intelligence they're insulting.