The Bulldozer Review: AMD FX-8150 Tested
by Anand Lal Shimpi on October 12, 2011 1:27 AM ESTFinal Words
In many cases, AMD's FX-8150 is able to close the gap between the Phenom II X6 and Intel's Core i5 2500K. Given the right workload, Bulldozer is actually able to hang with Intel's fastest Sandy Bridge parts. We finally have a high-end AMD CPU with power gating as well as a very functional Turbo Core mode. Unfortunately the same complaints we've had about AMD's processors over the past few years still apply here today: in lightly threaded scenarios, Bulldozer simply does not perform. To make matters worse, in some heavily threaded applications the improvement over the previous generation Phenom II X6 simply isn't enough to justify an upgrade for existing AM3+ platform owners. AMD has released a part that is generally more competitive than its predecessor, but not consistently so. AMD also makes you choose between good single or good multithreaded performance, a tradeoff that we honestly shouldn't have to make in the era of power gating and turbo cores.
Bulldozer is an interesting architecture for sure, but I'm not sure it's quite ready for prime time. AMD clearly needed higher clocks to really make Bulldozer shine and for whatever reason it was unable to attain that. With Piledriver due out next year, boasting at least 10-15% performance gains at the core level it seems to me that AMD plans to aggressively address the shortcomings of this architecture. My only concern is whether or not a 15% improvement at the core level will be enough to close some of the gaps we've seen here today. 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. My hope is that future derivatives of the FX processor (perhaps based on Piledriver) will boast much more aggressive Turbo Core frequencies, which would do wonders at eating into that advantage.
AMD also shared with us that Windows 7 isn't really all that optimized for Bulldozer. Given AMD's unique multi-core module architecture, the OS scheduler needs to know when to place threads on a single module (with shared caches) vs. on separate modules with dedicated caches. Windows 7's scheduler isn't aware of Bulldozer's architecture and as a result sort of places threads wherever it sees fit, regardless of optimal placement. Windows 8 is expected to correct this, however given the short lead time on Bulldozer reviews we weren't able to do much experimenting with Windows 8 performance on the platform. There's also the fact that Windows 8 isn't expected out until the end of next year, at which point we'll likely see an upgraded successor to Bulldozer.
So what do you do if you're buying today? If you have an existing high-end Phenom II system, particularly an X4 970 or above or an X6 of any sort, I honestly don't see much of a reason to upgrade. You're likely better off waiting for the next (and final) iteration of the AM3+ lineup if you want to stick with your current platform. If you're considering buying new, I feel like the 2500K is a better overall part. You get more predictable performance across the board regardless of application type or workload mix, and you do get features like Quick Sync. In many ways, where Bulldozer is a clear win is where AMD has always done well: heavily threaded applications. If you're predominantly running well threaded workloads, Bulldozer will typically give you performance somewhere around or above Intel's 2500K.
I was hoping for Bulldozer to address AMD's weakness rather than continue to just focus on its strengths. I suspect this architecture will do quite well in the server space, but for client computing we may have to wait a bit longer for a more competitive part from AMD. The true culprit for Bulldozer's lackluster single-threaded performance is difficult to track down. The easy answer would seem to be clock speed. We've heard of issues at Global Foundries and perhaps Bulldozer is the latest victim. If AMD's clock targets were 30% higher than Phenom II, it simply didn't make them with the FX-8150. I've heard future derivatives will focus more on increasing IPC indepedent of process technology and clock speed, but if you asked me what was the one limit to success I would say clock speed. As a secondary factor, AMD appeared to make some tradeoffs to maintain a reasonable die size at 32nm. Even then Bulldozer can hardly be considered svelte. I suspect as AMD is able to transition to smaller transistor geometries, it will be able to address some of Bulldozer's physical shortcomings.
The good news is AMD has a very aggressive roadmap ahead of itself; here's hoping it will be able to execute against it. We all need AMD to succeed. We've seen what happens without a strong AMD as a competitor. We get processors that are artificially limited and severe restrictions on overclocking, particularly at the value end of the segment. We're denied choice simply because there's no other alternative. I don't believe Bulldozer is a strong enough alternative to force Intel back into an ultra competitive mode, but we absolutely need it to be that. I have faith that AMD can pull it off, but there's still a lot of progress that needs to be made. AMD can't simply rely on its GPU architecture superiority to sell APUs; it needs to ramp on the x86 side as well—more specifically, AMD needs better single threaded performance. Bulldozer didn't deliver that, and I'm worried that Piledriver alone won't be enough. But if AMD can stick to a yearly cadence and execute well with each iteration, there's hope. It's no longer a question of whether AMD will return to the days of the Athlon 64, it simply must. Otherwise you can kiss choice goodbye.
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Iketh - Thursday, October 13, 2011 - link
I play FSX and Starcraft 2... both require copious processing power.And I just built an i7-2600K system with a radeon 6870 and blu ray writer for.... $960
paultaylor - Thursday, October 13, 2011 - link
While the benchmarks are very revealing of the "ahead of its time" nature of Bulldozer, I think AMD should've kicked off by focusing on server applications instead of desktop ones.Considering what I've seen so far I think some additional benchmarks on threading/scaling would come in handy – it would actually show the true nature of BD as, right now, it’s behaving like a quad-core processor (due to the shared nature of its architecture, I presume) in most cases, rather than an octacore. Charting that out might be very revealing. The situation now looks like Intel's 2nd (3rd?) generation hyperthreading quad-cores provide more efficient multithreading than 8 physical cores on an AMD FX.
Don’t get me wrong, we’ve heard from the beginning that BD will be optimised for server roles, but then we’re outside the feedback loop. Shouldn’t someone inside AMD be minding the store and making sure the lower shelves are also stocked with something we want?
A longer pipeline and the old “we’ll make it up in MHz” line reeks of Netburst, unfortunately, and we all know how that ended. Looking at the tranny count, it’s got almost twice as many as the Gulftown, with 27% bigger die size for the entire CPU… which will mean poorer yields and higher costs for AMD, not to mention that either the fabbing process is really being tweaked or the speed bumps will not come at all, as the TDP is already high-ish. Ironically it reminds me of Fermi. Speaking of which… BD may become the punchline of many jokes like “What do you get when you cross a Pentium 4 and a Fermi?”
On the other hand it seems AMD has managed one small miracle, their roadmaps will become more predictable (a good thing from a business perspective) and that will exert a positive influence with system integrators. Planning products ahead of the game, in particular in this 12-month cycle, might do some good for AMD, if they survive the overal skepticism that BD is currently "enjoying".
Other than that, another fine unbiased article.
rickcain2320 - Thursday, October 13, 2011 - link
Bulldozer/Zambezi seems to look more like a server CPU repackaged as a consumer grade one. Excellent in heavily threaded apps, not so hot in single threads.One CPU that is promised but isn't here is the FX-4170. I would have liked to see some benchmarks on it.
gvaley - Thursday, October 13, 2011 - link
We all get that. The problem is, with this power consumption, it can't make it into the server space either.kevith - Thursday, October 13, 2011 - link
Having waited so long for this, it´s a bit disappointing, when I compare price/performance.I went from C2D E 7300 acouple of years ago, and changed setup to Athlon II x2 250, and the performance difference made me regret right away.
And now, I have to change my MB and memory to DDR3 no matter what I choose, Intel or AMD. So I´ve looked forward to this release.
And it makes my choice very easy: I´l go back to Intel, no more AMD for me on the CPU side. And Ivy Bridge is coming, and will definetely smoke AMD.
Which is sad, it would have been nice with some competition.
eccl1213 - Thursday, October 13, 2011 - link
Earlier this week most sites reported that the FX and BD based Opteron 4200 and 6200 where both being released on Oct 12th.But I haven't found a single review site with interlagos benchmarks.
Have those parts been further delayed? We know revenue shipment happened a while back but I'm not seeing any mention of them in the wild yet.
xtreme762 - Thursday, October 13, 2011 - link
I haven't bought an Intel chip since 1997. But with this BS bulldozer launch, that is now going to change! amd should be ashamed of themselves. I for one will now sell all of my amd stock and purchase Intel. I will probably only end up with a few shares, but at this point, I cannot see supporting liars and fakes. And I will NEVER buy an amd product again, not a video card, cpu, mobo, not nothing! What a disappointment amd is.....All the amd crap I have will be tossed in the trash. I'm not even going to bother trying to sell it. WooHoo amd made a world record OC with a cpu not worth it's weight in dog poo!
connor4312 - Thursday, October 13, 2011 - link
Very interesting review. I'd be interested to see Bulldozer's benchmarks when it's overclocked, which, if I am correct, is higher than any Intel CPU can go. AMD seems to have made a turnaround in this aspect - Intel CPUs were historically more overclock-able.Suntan - Thursday, October 13, 2011 - link
As always, a very detailed review. But what about the capability of the "value" chips? Namely, is it worth it to spend around $100 to replace an Anthlon X4 with an FX4100?There are a number of us that picked up the X4 a couple years back for its low cost ability to encode and do general NLE editing of video. Is it worthwhile to replace that chip with the FX4100 in our AM3+ mobos? And what kind of improvements will there be?
As you rightly stated, a lot of us are attracted to AMD for their bang-for-buck. Just because the industry as a whole wants to bump up prices endlessly, there are still a lot of us that like to see good comparisons of the performance of CPUs available for around 1 Benjamin.
-Suntan
Pipperox - Thursday, October 13, 2011 - link
Frankly, it seems to me the disappointment of AMD fans to be quite excessive.Worst CPU ever?
What was then Barcelona, which couldn't compete with Core 2?
Bulldozer, set aside old single threaded applications, is slotting between a Core i5 2500 and Core i7 2600K.
Which other AMD CPU outperforms in any single benchmark a Core i7 2600k?
A higher clocked Thuban with 2 extra cores would have been hotter and more expensive to produce.
Setting aside AMD's stupid marketing, the AMD FX-8150 is a very efficient QUAD core.
The performance per core is almost as good as Sandy Bridge, in properly threaded applications.
Then they came with the marketing stunt of calling it a 8 core.. it's not, in fact it doesn't have 8 COMPLETE cores; in terms of processing units, an 8 core Bulldozer is very close to a Sandy Bridge QUAD core.
The only reason why Bulldozer's die is so large is the enormous amount of cache, which i'm sure makes sense only in the server environment, while the low latency / high bandwidth cache of Sandy Bridge is much more efficient for common applications.
I think with Bulldozer AMD has put a good foundation for the future: today, on the desktop, there is no reason not to buy a Sandy Bridge (however i'm expecting Bulldozer's street price to drop pretty quickly).
However IF AMD is able to execute the next releases at the planned pace (+10-15% IPC in 2012 and going forward every year) THEN they'll be back in the game.