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Benchmark Results: Power Consumption

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Idle power actually decreases if you decide to switch off CPU cores, but the difference isn’t large, thanks to optimizations in Intel's architecture that shut down unused execution resources when they're not in use anyway. We measured savings of 2% between six cores and just one.

Peak power scales very linearly. If you were to switch off five out of the six cores, our Core i7-980X machine would require only 122W at peak load rather than 223W. This would be a single-core 32 nm processor with 12MB L3 cache and a 3.2 GHz clock speed running at only 54% of the peak power of six cores. Keep in mind that performance drops much more, though. This is just a hypothetical example.

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The Greater Good 07/07/2010 6:53 AM
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Nice review. To be honest, I didn't really expect anything less.

bitplayer 07/07/2010 6:59 AM
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Well done Tomshardware, the comparison between platforms in respect to core count and memory bandwidth saturation was enlightening; Intel having the upper hand with triple channel memory. When 2-4 cores saturate "global memory" bandwidth, developers should take note and differentiate between tasks which require "global memory" and those best executed in cache.
Again, well done and thanks.

chefboyeb 07/07/2010 7:05 AM
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eddieroolz 07/07/2010 7:26 AM
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Although I think it was a forgone conclusion that more core count = better, it's nonetheless good to get actual confirmation.

SchizoFrog 07/07/2010 7:33 AM
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Can I just ask why in this type of article you never mixed 'professional' apps with more 'home user' apps, namely games? It would be of massive benefit to a variety of consumers to cross reference the pros and cons from both sides in the same article.

As an example, Bit-Tech just did an article on the benefits of multi-cores in games, but they too didn't mix that article against other more professional apps. So it is difficult to see the best of both worlds.

Here is the Bit-Tech article for reference.
http://www.bit-tech.net/hardware/c [...] mes-need/1

haplo602 07/07/2010 8:19 AM
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I don't get it. Why benching single applications on a multicore system ? You can have many background tasks running and still game on the system. However you are only testing sequential workloads.

What's the use of having multicore systems when you are NOT using them ? Put a video decode, torrent download, lightroom image exports in the background and then bench a game.

Or better yet, UPDATE your testing methodology to properly deal with multitask hardware.

Tamz_msc 07/07/2010 9:17 AM
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It would have been better if you included the results from the Phenom II X6 test side by side with the results from these tests.

thejerk 07/07/2010 11:21 AM
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"Clearly, the difference between one, two, and four cores is significant, while adding cores five and six don't yield the same performance jumps."

I think you misinterpret your own data. The turning point is actually at three cores, and not four.
Significantly diminishing returns are seen thereafter.

angryfingertips 07/07/2010 12:05 PM
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haplo602 :
I don't get it. Why benching single applications on a multicore system ? You can have many background tasks running and still game on the system. However you are only testing sequential workloads.What's the use of having multicore systems when you are NOT using them ? Put a video decode, torrent download, lightroom image exports in the background and then bench a game.Or better yet, UPDATE your testing methodology to properly deal with multitask hardware.



I agree with you on this one. Just a few years ago, ok maybe 5 or so, you could not not play a video game and run anti-virus at the same time. Today you can do that with the 4 cores. Multi-core is more than just how fast it gets one thing done, it is how fast it gets multiple things done.

gfg 07/07/2010 12:27 PM
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100% bandwiht utilization
Intel 2 core
AMD 4 core

Then ddr3 1333 vs ddr3 2000, is valid for some applications.
Maybe winrar is a good example:
Intel good increase up to 2 cores
AMD good increase up to 4 cores

Conclusion:
- memory speed in theory, for the architecture of microprocessors, should provide an increase in performance. Although according to tests is not so, so application developers should take more advantage of the bandwidth provided.

sorry my english.

bigbopper66 07/07/2010 1:43 PM
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Nice article, and I agree with many of the previous comments on multitasking. You mentioned the lack of multi-threaded applications, but that's just in the windows world. Take a look at most Linux apps, and you will find that they are able to take advantage of the multiple cores, and have been that way for many years, even before multicore processors were mainstream, or even available.

cablechewer 07/07/2010 3:03 PM
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I agree with the previous posters about needing to see benchmarks with professional applications. Many of your readers are also in the IT industry and their home gaming rigs often double as lab machines running multiple VMs when they have home work to do (if they are 'playing' in the server world) or they run other professional software for when work, training or schooling follow them home.

The only question is what professional apps to test and does anyone at Tom's have the expertise with those apps (Compilers? Databases? Mail Servers? CAD? Multiple, large, inter-linked spreadsheets when they recalc?)? Is there another site you could partner with? I just did a casual search and didn't find any other sites (like Tom's, but based on Professional software), but I didn't spend a lot of time on it yet.

infodan 07/07/2010 3:22 PM
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subject to how many tabs you have open, title Not work safe!

lapoki 07/07/2010 4:22 PM
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infodan :
subject to how many tabs you have open, title Not work safe!


LMAO

ta152h 07/07/2010 4:35 PM
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The first article on scaling with six-cores had me scratching my head. Then to follow it with this one is even more bizarre. So, we came to the conclusion that if you buy a six-core processor, you should leave them all on?

Or with multi-threaded apps, six cores can make a difference. With limited threads, it's not as effective?

Maybe I'm a simpleton, but I kind of figured that without doing all the tests. What's next, a test showing that if you buy a keyboard, it generally makes sense to leave all the keys on there and not remove them, because if you do a lot of typing, you'll probably end up using them?

Most of the articles on Tom's make sense. These seem to come to an obvious conclusion that are pretty much understood without even testing.

wolfram23 07/07/2010 4:39 PM
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Seems logical, but I would have liked to see results from turbo boost.

awood28211 07/07/2010 4:49 PM
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When are we going to see benchmarks that show two (or more) applications running at once. What if I wanna do a movie conversion at the same time I use winrar to compress files?

iqvl 07/07/2010 6:05 PM
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haplo602 :
I don't get it. Why benching single applications on a multicore system ? You can have many background tasks running and still game on the system. However you are only testing sequential workloads.What's the use of having multicore systems when you are NOT using them ? Put a video decode, torrent download, lightroom image exports in the background and then bench a game.Or better yet, UPDATE your testing methodology to properly deal with multitask hardware.


The difference between 4-core and 6-core when many applications run at the same time will be very similar to when one 6-threaded application is run. For example, when one 6-threaded and one 4-threaded apps run at the same time, the difference of time taken to complete the tasks between 4-core and 6-core will be very close to when one 6-thread apps is run if they are as fast in four or less threaded apps(i.e. quad i7 v.s. hex i7, instead of quad i7 v.s. PII-X6).

Update:
This is the reason why PII-X6 loses to quad i7 when most apps run at the same time are four or less threaded(especially after all 6-thread of X6 are occupied) which is the most common cases(90%+) to the majority. Forget about the hex, save the money towards SSD, more RAM or better GFX for better overall performance.

elbert 07/07/2010 7:36 PM
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Very good article. Well presented but I have a different conclusion. Seems to me the only real advantage going from 4,5,6 cores is mostly simulation. Simulation being many programs running at once. If running many programs is your thing then more cores the better for you. I mostly run 1~3 programs as most all programs require some human involvement. I cant see adding more CPU cores in the future benefiting the average PC users.

The very best program multi-threaded seems to produce little benefit beyond 4 cores. I'm looking forward to the APU with hope it solve the overhead. The efficiency test seem to really highlight the drop off beyond the 4th core.

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