The Vishera Review: AMD FX-8350, FX-8320, FX-6300 and FX-4300 Tested
by Anand Lal Shimpi on October 23, 2012 12:00 AM ESTPower 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:
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):
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CeriseCogburn - Tuesday, October 30, 2012 - link
Problem is you have that attitude more than once, and then you're into a slow degrading slop with lost performance.So, why do we get these arguments from amd fanboys ?
Obviously you purchased the 6950 and decided you needed every last drop of juice from it, and there you go, oc'ed to 6970...
So on the one hand you've takena safe and sufficient card and hammered the piss out of it for a few more frames you cannot notice, as you do tell us you cannot notice them, and then you take your cannot notice them argument, and claim that's why your amd cpu is so great... and intel is not needed.
I see you did that without even noticing. You totally freaking contradicted yourself, completely.
Look, go ahead and buy amd and be a fanboy, I say more power to you, just DON'T type up crap talking points with 100% absolute contradiction, plussing them blatantly in amd's favor, and expect I'l just suck em down like freaking koolaid.
DO NOT.
Intel is desired for the very same reason, you the amd fanboy, bought the 6950 and have it OC'ed to 6970 speeds.
Sorry bub, nice try, till you ate both your own shoes.
Ellimist - Tuesday, October 23, 2012 - link
I would also like to see virtualisation in benchmarks as well. Multi core processors should lend to some interesting results in these sort of benchmarks.Good Review btw. Keep up the good work.
silverblue - Tuesday, October 23, 2012 - link
I think that's Johan's domain; expect him to do so when he looks at the new server-based models.HW_mee - Tuesday, October 23, 2012 - link
The 8320 is a 125W partCeriseCogburn - Tuesday, October 30, 2012 - link
LOL - oh dats not much powa ! All da amd fanboys don't care about power or saving the earth, they never cared, they never are worried, nor have they ever been worried about housefires...All that hate toward JenHsung and all those years of destroying the earth rage against nVidia, that actually happened on another planet in an alternate universe.
gamoniac - Tuesday, October 23, 2012 - link
Anand, while enjoying your Vishera review, upon loading a page, the ad on your page took over my browser and navigated to a fishy looking "You are today's 100,000th visitor!" site. I know AT contracts out the ad part, but I thought you might be interested in knowing what happened. Here is a screenshot of what I experienced -- http://i45.tinypic.com/2aigegx.jpgGood reading, as always.
Ryan Smith - Tuesday, October 23, 2012 - link
Thank you for reporting that. I'll see if I can track down the source and get them removed.artk2219 - Tuesday, October 23, 2012 - link
Thanks for the review and all of the time that went into it! It looks like I can finally start recommending something that isn't a Phenom II from AMD. Even though I personally love AMD and haven't used an intel chip since the P3 coppermine days, I couldn't recommend anything from AMD to anyone else this past year with a clear conscience, at least if it wasn't a stand alone CPU upgrade. But from the tests that I could find that compared the fx 4300 to the i3 3220 it looks like its mostly a wash between them, well other than power usage and thermals that is, so that was looking great! Is there any chance of a stand alone review in the future comparing the two? It looks like the 8350 performs about like a 2500K which is also awesome, unfortunately it's at least a year late to the party :(. This does however give me great hope for Steamroller, the only issue I had with the article is with the games selection (too few and too intel biased in the titles (SC2 and WOW)), might there be a more in depth review on that in the future as well? Thanks again for the review though!CeriseCogburn - Tuesday, October 30, 2012 - link
Wow hi there. Glad to meet you, an amd fanboy with the glimmers of a conscience.Now, don't forget the i2500K Oc's from 3200 right on up to 4500 (and beyond) on stock voltage and crap stock fan, so it actually SMOKES the daylights out of this fishy vishy.
Just thought I'd mention that.
SilthDraeth - Monday, October 22, 2012 - link
That was weird, was reading this article about Vishera and it got pulled in the middle of me reading it.