Power Consumption

With Vishera, AMD was in a difficult position: it had to drive performance up without blowing through its 125W TDP. As the Piledriver cores were designed to do just that, Vishera benefitted. Remember that Piledriver was predominantly built to take this new architecture into mobile. I went through the details of what makes Piledriver different from its predecessor (Bulldozer) but at as far as power consumption is concerned, AMD moved to a different type of flip-flop in Piledriver that increased complexity on the design/timing end but decreased active power considerably. Basically, it made more work for AMD but resulted in a more power efficient chip without moving to a dramatically different architecture or new process node.

In mobile, AMD used these power saving gains to put Piledriver in mobile APUs, a place where Bulldozer never went. We saw this with Trinity, and surprisingly enough it managed to outperform the previous Llano generation APUs while improving battery life. On desktops however, AMD used the power savings offered by Piledriver to drive clock speeds up, thus increasing performance, without increasing power consumption. Since peak power didn't go up, overall power efficiency actually improves with Vishera over Zambezi. The chart below illustrates total system power consumption while running both passes of the x264 HD (5.0.1) benchmark to illustrate my point:

In the first pass Vishera actually draws a little less power, but once we get to the heavier second encode pass the two curves are mostly indistinguishable (Vishera still drops below Zambezi regularly). Vishera uses its extra frequency and IPC tweaks to complete the task sooner, and drive down to idle power levels, thus saving energy overall. The picture doesn't look as good though if we toss Ivy Bridge into the mix. Intel's 77W Core i5 3570K is targeted by AMD as the FX-8350's natural competitor. The 8350 is priced lower and actually outperforms the 3570K in this test, but it draws significantly more power:

The platforms aren't entirely comparable, but Intel maintains a huge power advantage over AMD. With the move to 22nm, Intel dropped power consumption over an already more power efficient Sandy Bridge CPU at 32nm. While Intel drove power consumption lower, AMD kept it constant and drove performance higher. Even if we look at the FX-8320 and toss Sandy Bridge into the mix, the situation doesn't change dramatically:

Sandy Bridge obviously consumes more than Ivy Bridge, but the gap between a Vishera and any of the two Intel platforms is significant. As I mentioned earlier however, this particular test runs quicker on Vishera however the test would have to be much longer in order to really give AMD the overall efficiency advantage.

If we look at average power over the course of the two x264 encode passes, the results back up what we've seen above:

Power Consumption - Load (x264 HD 5.0.1)

As more client PCs move towards smaller form factors, power consumption may become just as important as the single threaded performance gap. For those building in large cases this shouldn't be a problem, but for small form factor systems you'll want to go Ivy Bridge.

Note that idle power consumption can be competitive, but will obviously vary depending on the motherboard used (the Crosshair Formula V is hardly the lowest power AM3+ board available):

Power Consumption - Idle

3D Gaming Performance Projected Performance: Can AMD Catch up with Intel?
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  • Granttamaid - Tuesday, June 11, 2013 - link

    Remember Price vs performance, AMD always win against intel. Well, intel has the fastest processor in the world,.... but, do you need all the intel's potential power? i don't think so.
    some people only use their computer for internet browsing even they have intel core i7.
  • pantong - Monday, July 8, 2013 - link

    I see most comments talking about how this card is shit.

    Sigh.

    This card works great for what I need it to do. I host 7 servers on my computer on v boxes for my gaming community. Mine craft, ts, star made, cube world, ect... I don't get paid for my services and I need it cheap. This card give performance to host a lot of people on each on each core. From a low 4 people on cube world to 45+ on team speak.

    Why would I buy Intel for these purposes other than to spend money for same performance in the scenario and flaunt my epeen.?

    Performance is not based on score or GHz. Its based on money.
    So before saying this card is shit. Why not look at multiple applications that this card can be used it.

    As far as this scenario goes. Any unused CPU is lost money.
  • Ukdude21 - Thursday, August 15, 2013 - link

    You keep complaining about amd fanboys, but your obviously an intel fanboy... You sound completely immature with your constant us of LOL in caps.
    No need to get too excited about cpu's... They are just part of a machine that you use lol.
    Seriously you should not post on this website if you are just going to be a immature intel fanboy.
    You sound too young to be posting on this website anyways.
    "obnoxious insolence" you should re-read your post as it is completely obnoxious.
    Your attitude stinks -.-
  • Gholt - Thursday, August 29, 2013 - link

    All those Intel & AMD Fanboys.. Holy crap -_-
    I have an FX-8350 and had an i7 in the past.
    I went for the FX-8350 since it was so much cheaper compared to the i7 3770K while having almost identical performance, AMD just can't be beaten by their Price-Performance products, however Intel's best CPU's will Always be better than AMD's best, thats a fact to be known.
    BUT, that doesnt make AMD bad, like all these Intel ''Fanboys'' seem te think, Intel and AMD are both bad and good in their own way, get the fuck over it both you AMD AND Intel fanboys.
  • alcomenow - Friday, October 11, 2013 - link

    If you live in a hot and humid climate an FX processors would be a terrible value. Most people that live in central Florida use air-conditioning 80% to 90% of the year. For my uses the equivalent AMD CPU's have been tested and shown to consume about 65 watts more under full load and 11 watts under idle conditions than a comparable Intel CPU. Since I pay 100% of the electrical bill then buying a Intel CPU will become a significant cost saving purchase over 4 or 5 years.
    Well, 10 or 50 watts might not seem like it would cost much. If you factor in daily usage, a/c cost, and 4 years of ownership than the pennies start to add up.

    1w * 12hrs/day = 4.3kw/hrs/yr
    4.3kw * 0.8 a/c cost = 7.7kw * $0.11 kw/hrs = $0.85 yr
    $0.85 * 4 yr = $3.40 per watt
    example $3.40 * 30w = $102

    1w * 24hrs/day = 8.6kw/hrs/yr
    8.6kw * 0.8 a/c cost = 15.4kw * $0.11 kw/hrs = $1.7 yr
    $01.7 * 4 yr = $6.80 per watt
    example $6.80 * 50w = $340

    If I was building someone a budget gaming desktop, I would recommend spending $130 on a Intel Core i3-3225 Ivy Bridge 3.3GHz LGA 1155 55W Dual-Core Desktop Processor Intel HD Graphics 4000 running at stock speeds instead of spend $120 on a AMD FX-6300 Vishera 3.5GHz (4.1GHz Turbo) Socket AM3+ 95W Six-Core Desktop Processor even if overclocked to 4GHz. 
  • ToeringsNthong - Saturday, January 11, 2014 - link

    Quote""Single threaded performance is my biggest concern, and compared to Sandy Bridge there's a good 40-50% advantage the i5 2500K enjoys over the FX-8150"I know this is an old post BUT i just bought its big bother the FX 8350 for $129.99 ,and they are saying the same thing,poor single thread performance.I say WHO CARES? I know most people that have 1/2 a brain don't care!! Most people buy this CPU for gaming !What games can you name are single threaded???unless you go back to the stone age ! and are playing the very 1st battlefield 1942?thats all i do is game and transcode videos and dollar to dollar this thing kicks intels a s s! so case closed!!!! AMD all the way FTW
  • mersastra - Thursday, January 16, 2014 - link

    1st time in ages pondering an upgrade , why I don't know as what I have doe's everything i need to , I don't game by the way. Sitting on Phenom11 Quad 965 Black Edition , gently O/c to 3.7ghz . Asus M4A88TD-evo with 16GB of memory. Not impressed with bench marks in the least , used to laugh at them with lenses when I used to do photography , meaningless in the real world mostly. pondering this chip , currently about £143. Been building machines since 286 days and always use AMD , never let me down , have been with several Intel ones. If AMD went bust leaving Intel with a monopoly, would price out of our reach. My thoughts anyway. Not really bothered which chip as long as it works , each to their own , don't understand the squabbling. lol.
  • LBJ - Saturday, January 18, 2014 - link

    Did you look at the games benchmarks in this review? It's not that games only use a single thread, it's that plenty of games are no optimised well for multi-threaded CPUs. If we're talking about BF4 fine, the FX chips will perform well against Intel, but it's clear from these benchmarks that in plenty of titles from the past few years that the poor per-core performance of the AMD chips does hamper its gaming potential.
  • Chromatose - Sunday, February 2, 2014 - link

    And the fanboyism repeats itself again.... AMD is slowly creeping up to Intel, eventually they would have to be equal. AMD does good at 3D modelling, video editing and gaming, Intel is suited more for video editing, rendering and graphics. AMD is low price and value. If you can OC it properly and with good cooling, it beats Intel in SOME areas. Intel, on the other hand, can deliver a tad more power with lower clock speeds.

    AMD has less framerate from Intel, but only a *slight* difference in performance. AMD is known to have weak cores and make it up by adding 8. Intel has slightly more power in each core, but mainly goes up to 6 cores.

    My conclusion? AMD should stop fighting with Intel and slowly work their way up from there.
  • Melcinitan - Thursday, June 19, 2014 - link

    Ok people,lets just agree that nothing is free of charge.We HAVE TO PAY to get these badboys on our pcs so you can stop bitchin about "price dont matter".
    AMD FX 8320 is around 160$.lets check for the same price to intel right?Intel - Core i3 Dual-core i3-4340 is what i found on the net after a quick search. If you tell me that i3 guy can best FX 8320 than yep Intel is the winner.But if you try to compare i7 and this fx guy,thats wrong.
    I think amd tries to sell cpus to middle-class folks who only wants to have best performance with a weak salary and Intel is trying to do the best of the bests regarding how much it will cost. If you have lots of money buy an intel and have fun of it. If you dont have that much money but still need some performance go for AMD.

    My opinion is giving half the money and have a tick less of performance.I'll live.

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