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?


View All Comments

  • BellFamily7 - Tuesday, October 23, 2012 - link

    I think in Final Words Anand should add: "And the 4 year old Intel i7-920 - what a chip that was/is!" It is startiling to see AMD barely keep-up with the venrable 920 a good four years on - and those first charts in this article are with the i7-920 at stock speed. The average enthusiast is running an i7-920 at 3.8 Ghz on air all day long and achieving performance on par - or better - than many of today's CPU's!
    Of course, there is one big downside - power. This is Intel's big story to me: the speed and power of an O/C'd i7-920 on one quarter (or less) the power. Cool!
    Thanks for putting the old i7-920 in the mix - it shows just what a ground breaking design it was...and in many ways, still is.
  • Senti - Tuesday, October 23, 2012 - link

    Indeed i7-920 is the most awesome CPU in those graphs considering its age and nice overclockability. If there was overclocked version of it graps would look pretty funny.

    I use i7-930 @ 4.1 for a long time now and just can't justify my itching urge for upgrade. More than that, it'll probably survive here for 2 more years until Haswell-EP as plain Haswell looks handicapped in terms of compute power in favor of iGPU and power draw. I do NOT need power-restricted desctop CPU – with power saving features it'll do fine on idle with any max TDP.
  • ClagMaster - Tuesday, October 23, 2012 - link

    With comprehensive ECC at the same price this would make a good server or workstation chip.

    AMD needs to get a 22nm process going and start some serious architectural soul-searching.
  • bwcbwc - Tuesday, October 23, 2012 - link

    I don't understand why you keep saying that the 6300 fails to beat Intel at it's price point for the multi-threaded tests. At $130-140, the 6300 is going up against the core i3's and the multi-threaded benchmarks show the 6300 beating the core i3. Seriously: what am I missing here? Reply
  • Rhezuss - Tuesday, October 23, 2012 - link

    I'd have loved to see the PHenom II X4 980 BE or any X6s in the comparisons... Reply
  • nleksan - Tuesday, October 23, 2012 - link

    I can't see this as anything but a "win" for AMD, although there are certainly some sad feelings lingering about as I read this article regarding the 15% employee layoff that recently occurred. The promise AMD made was 10-15% improvements in IPC, and we certainly got that; not only that, but at a lower price than the first generation, AND with some very promising overclocking potential based on the scaling shown in this article.

    However, I refuse to acknowledge these as "FX" chips. "FX" was the designation given to the very first CPU produced by AMD that outperformed Intel's best offerings by a significant margin, the Socket 940 FX-51 2.2ghz single-core CPU based on the Opteron version of the Athlon64 architecture. The reason for my petty "harrumph-ing" is that I own one of the very first FX-51 chips released (from the first batch of 1,000), purchased the day of release back in 2003 alongside an Asus SK8V motherboard with 2GB of Corsair XMS3200RE DDR-400 Reg/ECC Dual-Channel RAM, and which served admirably with its brother the X800XT-PE 256MB GDDR2, until its well-deserved retirement in 2009.
    That chip was, and to this day is, my favorite CPU of all time. It was a quirky chip: a server-backbone (and consequent unusual socket choice), ahead-of-its-time 64bit architecture, record-setting bandwidth at a "low" 2.2Ghz while Intel was trying their darnedest to hit 4.0Ghz with the P4, no real options in terms of a future upgrade path, and its champagne-tastes that could only be satiated by incredibly expensive Registered memory. However, it was FAST as all get-out, ran nice and cool with a Thermaltake Silent Tower Plus, and had a good amount of overclocking headroom for the time (an extra ~200-280Mhz was common).
    Oh, and it DEMOLISHED the Pentium IV Emergency Edition CPU's that came clocked 55% higher! Paired with the best video card the world had ever seen at the time, it was unstoppable, and I recall running 3dMark for the first time after the build was finished only to nearly poop myself, as this 2.2Ghz chip STOCK just out-performed every single Intel CPU on the charts outside of those OC'd with the help of LN2.
    I am working right now to rebuild the rig, as I feel it is time for it to come out of retirement and have some fun again, and I want to see just what it really is capable of with some better cooling (extreme-air or decent water).
    [SPOILER]I have already lapped the CPU and the block (I am amazed at how poorly the two mated before; the chip AND cooler were noticeably convex), and based on the flatness of each it will certainly be good for a few degrees; add in the magic of today's best TIM's (PK-1) compared to that of 2003, the wonders of modern computer fans via 2x 92mm 3800rpm 72cfm/6.5mmH2O fans doing push-pull, and an extra 3 intake fans feeding it fresh air.... It will be a fun way to bring a memory back to life :D
    Plus, the X800XT-PE has been thoroughly prepped for overclocking, with a 6-heatpipe heatsink and 92x20mm (61.3cfm/3.9mmH2O) swapped for the stock unit and mated with PK-1, EnzoTech Pure-Copper VGA RAM-Sinks attached to all of the card's modules with PK-1 and less than a needle-tip's worth of superglue at two of the four corners of each, and the same for the MOSFET/VRMs on the card. Combined with a pair of 120mm 69cfm fans blowing air across it (mounted on the inner side of the HDD cage opposite an intake fan), an 80x15mm 28.3cfm fan mounted to blow air directly on the back of the card, a PCI slot blower fan pulling hot air from the card and exhausting it out the back, as well as an 80x25mm 48cfm fan mounted where the lower PCI brackets used to be exhausting air... I think it'll do just fine ;)

    However, I am not taking any sides in this "CPU WAR". The minute one company starts to seriously pull ahead, the competition is lost, and we ALL lose. Innovation will become scarce, people will become excited about 5% IPC improvements from generation to generation and fork out the money for the next "great thing" in the CPU world, not to mention the cost for the constantly-changing socket interface.
    AMD has been in a bad way for some time now, pretty much since the Core processors from Intel began to overrun their Phenom lineup. Sure, they had some really amazing processors for the money, such as the Phenom II X4 965BE/980BE/960T and X6 1055/1090/1100T, but Intel was still the performance leader with their E8600, Q6600, and the many QX9xxxx processors that transitioned into the still-strong X58/1136 platform (with the 920/930/975X/990X standing out), and they have only gained traction since.

    I am no fanboy, and I hate to get onto any enthusiast site and scroll through comments sections where pimply-faced, Cheetoh-encrusted, greasy-haired know-it-all loser's frantically type away in a "Heated Battle of 'Nuh-Uh's' and 'Yuh-HUH!'".
    (that is called hyperbole)

    Fortunately, at least for the most part, I don't see that here.

    Perhaps we should all go out and buy one of these new chips, maybe for a build for a friend or family member, or a home-theater PC or whatever, but regardless of whether you "Bleed Red" or "Bleed Blue", both "sides" will win if AMD gets the money to truly devote enough resources to one-upping Intel, or more likely, coming close enough to scare them. When the competition is closest, only THEN do we see truly innovative and ground-breaking product launches; and at the current rate, we may be telling our grandchildren about how "once, a long time ago, there was a company.... a company named AMD".

    For the record, I AM NOT in any way a Fanboy; I buy whatever gives me the best bang-for-my-buck. Fortunately, at my job I am the only "tech-y" person there so whenever there is an upgrade in someone's equipment, or even servers, I get the "old" stuff :D I have sold literally hundreds of CPU's off that I had no use for, but I kept the favorites or the highest-end in each category that I was able to get. However, many of them I purchased myself (Opteron/Xeon from work, the rest I bought 90% of).
    Here's a list of processors I currently have in possession, in my house, in the best reverse-chronological order I can remember:
    i7-3930K (24/7 4.6Ghz - Max 5.2Ghz), i7-3820QM, i7-2600K, 4x Xeon E7-8870 (got 8 for $2k from work, sold 4 @ $2k/ea and built a Bitcoin Miner that earned me ~6,700Mh/sec with 4x 5970's in CF-X; earned over 1200BC and cashed out when they peaked at ~$17/ea for a massive profit and eventually stopped mining), i5-2400, Xeon X5690, i5-2430M, Opteron 6180SE 12-core, Xeon W3690, Phenom II X6 1100T-BE, Phenom II X4 980-BE, Phenom II X4 960T-BE (built girlfriend a rig: best CPU for $$; unlocked to 6-core; hits 4.125Ghz 6C / 4.425Ghz 4C), Xeon X7460, Core2Quad Q9650, 4x Xeon X3380's, Opteron 8439SE, Xeon X5492, Core2Duo E8600 (from Optiplex 960, hits 4.5Ghz on air), Core2Duo T7400, Athlon II X4 640 (E0), Athlon II X4 650, Pentium Dual-Core T4400, Turion II N550 Athlon X2 7750BE, AMD FX-62 (3.25Ghz easy), Xeon X3230, Athlon X2 5200+, Opteron 890, Turion II Ultra M660, Athlon64 X2 6400+ BE, Opteron 185, Athlon64 X2 4800+, Opteron 856, Opteron 156, AMD FX-51 (24/7 2.45Ghz stock voltage), Opteron 144 (OC'd to ~2.6Ghz), Turion ML-44, Pentium 4-EE 3.46Ghz (could barely hit 3.5Ghz...junk), Pentium 4 3.2Ghz, Pentium 4 2.8Ghz (easily ran at 3.6Ghz on air 24/7 with +0.015V, awesome CPU!), Celeron Mobile 1.6Ghz, Pentium 4 2.4Ghz, Celeron 1.8Ghz, and plenty more....
    ***Have a set of 8x Xeon-EP E5-4650 8-core's coming when we upgrade again in January; they are upgrading the whole rack so I am getting, along with the chips: 3 total 4-CPU boards, 384GB of DDR3-1333 Reg/ECC, the entire cooling system, 16x LSI/Adaptec RAID Controller Cards (all PCI-e x8, support minimum 24x SAS 6Gbs drives, have between 1 and 4GB of Cache, and all have BBU's), 96x 150GB 15Krpm SAS6 + 48x 600GB 15Krpm SAS6 enterprise drives, and about two-dozen Nvidia "professional" cards (12x Tesla M2090's, 4x Tesla K10's that were used to evaluate platform, and 8 Quadro 6000's) all for $1900!!!!!!!! The supplier offered $2150 for "Trade-Up" but I am really good friends with the entire IT department (all 6 of them) and they offered them to me instead! FOLDING@HOME WILL BE SHOWN NO MERCY!
  • CeriseCogburn - Tuesday, October 30, 2012 - link

    Ok idiot, I've had enough already.

    First of all, nice amd fanboy story. Before you go insane claiming over and over again it is not true, I want to point out to you your own words....

    1. Intel has been dominating since core 2
    2. Without amd competing there will be no innovation and tiny 5% will cost and arm and a leg and the idiots will be spending all their money buying it

    Okay, let's take those 2 statements, and add in SANDY BRIDGE and it's amazing architectural jump.
    Whoops !
    There goes your sick as heck and fan boy theory.

    Furthermore with your obviously supremely flawed BS above, you did your little amd fanboy promotion saying we should all go out and buy one of these amd chips for a family member or some upgrade - BLAH BLAH BLAH BLAH BLAH.

    Let's add in your eccentric Fx chip story, your declaration it's your favorite cpu of all time, your bashing of Intel claiming only Ln2 could bring Intel close, and then your holy of holies the resurrection build...

    OK ? Forgive any and all of us who don't buy your I am not an insane amd fanboy lines.

    Look in the mirror, and face the dark side, let it flow through you Luke, you are and amd fanboy, and Intel will innovate and make absolutely amazing cpu's like the SB even when amd is slapping itself in the face and choking and dying ... feel the anger amd fanboy - amd is NOT NEEDED... let it flow through you amd fanboy, your journey to dark side is nearly complete...
    When you kill your greatest FX cpu rebuild, you will have crossed over to the darkside !
  • Ukdude21 - Thursday, August 15, 2013 - link

    Geez I think this intel fanboy should stfu and stop talking a load of verbal shit lol. Reply
  • redwarrior - Tuesday, October 23, 2012 - link

    I looked over the tests this character devised. ONly a few were multithreaded. Tom's Hardware had a very through testing procedure , explaining eacg application and what it showed about the architecture of the various cpus being compared. They were very balanced in single threaded apps and multithreaded apps. They did NOT do a lot of synthetic benchmarks because many of them are skewed in a prejudicial way. He also used win zip , photoshop cs5, video editing software, etc. Games were not all single thread shoot-em-ups, they were a collection of widely diverse games.. The FX-8350 came out ahead of not only the I5 3450 but also the I5-3570. He had some criticisms of course , but he said it was the best bang for the buck in the $200 price space. This review was shallow and meaningless done by somebody who either is lazy or on a mission to discredit. By the way The FX-8350 had the highest score on win zip bettering even the I7 3770. This reviewer owes us a well-designed retest and apology for a bunch of misleading garbage. Reply
  • silverblue - Wednesday, October 24, 2012 - link

    Well, that's the beauty of product reviews - there are multiple for a specific product, and all with different tests. What you need to do is find the test that matters to you, and if it excels at it, you may buy it solely based on that (even ignoring bad points). If, on the other hand, it doesn't perform so well in the discipline of your choice, that is really making your mind up for you to go buy something else. Reply

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