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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saneblane - Thursday, October 13, 2011 - link
Man, you have a lot of optimism. I am a big Amd fan, but even i can remain optimistic after this mess, I mean how do you make a chip that is slow, expensive and losses to it's older brothers. Barcelona was a huge success compare to this, it only seemed bad because Expectations were high, this time around though they became higher because no one expect Amd to actually go backwards in performance. WOW that's all i can say WOWPipperox - Thursday, October 13, 2011 - link
I don't understand why you all think it's slower than its older brothers.It's not, it's faster than Thuban in practically all benchmarks...
Or do you really care about stuff like SuperPi?
Pipperox - Thursday, October 13, 2011 - link
But maybe you guys think that it's slower "clock for clock" or "core for core".It doesn't matter how you achieve performance.
What matters is the end performance.
Bulldozer architecture allows it to have higher clock speed and more *threads* than Phenom.
The penalty is single threaded performance.
Again you can't compare it to an hypothetical 8 core 4.0GHz Thuban, because they couldn't have made it (and make any money out of it).
I'll repeat, the FX-8150 is NOT an 8-core CPU.
Otherwise the i7-2600K is also an 8-core CPU... both can execute 8 threads in parallel, but each pair of threads shares execution resources.
The main difference is that Sandy Bridge can "join" all the resources of 2 threads to improve the performance of a single thread, while Bulldozer cannot.
They probably didn't do it to reduce HW complexity and allow easier scalability to more threads and higher clock speed.
Because the future (and to a large extent, the present) is heavily multithreaded, and because Bulldozer is targeted mainly at servers. (and the proof is its ridiculous cache)
bryman - Thursday, October 13, 2011 - link
how about some bios screenshots? Is there a way in the bios to disable the northbridge in the chip and use the northbridge on the motherboard? Possibly better performance, or maybe add a new ability to x-fire northbridges? (Yah imah Dreamer). imo, I dont think adding the northbridge to the cpu was a good idea especially if it pulls away from other resources on the chip, I understand what adding the northbridge to the processor does, but does it turn off the northbridge thats already on the motherboard? The northbridge on the chip makes sense for an APU but not for a perfomance CPU, why is the nothbridge even in there. I myself would rather see the northbridge on the motherboard utilizing that space intstead of the space on the cpu.If there isnt a way to turn off the northbridge on the cpu in the bios, i think the motherboard manufactures should include the ability to turn off the northbridge on the cpu. Add the ability to use the onboard northbridge in there bios, so you can atleast get bios or firmware updates to the northbridge and perhaps get more performance out of the cpu/gpu.
When the new Radeon 7000 series video cards come out, if I buy this CPU with the 6000 series northbridge in it, am I going to take a performance hit or am i going to have to buy a new processor with the 7000 series northbridge in it? or will they come out with a 7000 series motherboard that utilizes a 7000 series northbridge that turns off the 6000 series northbridge in the chip, which in turn makes it useless anyways. I myself dont like the fact if i buy this product, if i want to upgrade my northbridge/ motherboard, I might have to buy a new processor/ perhaps a new motherboard or am i just paranoid or not understanding something.
Who knows, maybe in the next couple of weeks, Mcrosoft and/or AMD will come out with a performance driver for the new processors.
If they would have come out with this processor when planned originally, it really would have kicked butt. instead we get conglimerated ideas over the five year period, which looks like the beginning idea, thrown into a 2011 die.
I am i die-hard AMD fanboy and always will be, Just kinda dissappointed, excuse my rants. I will be buying a 4 core when they hit the streets, hopefully in a couple weeks.
saneblane - Thursday, October 13, 2011 - link
From the caching issues, to the bad glofo process, to the windows scheduler, i recon that this processor wasn't ready for prime time. Amd didn't have any choice i mean they almost took an entire year extra for peet sake. Even though my i5 2500 is on it's way, am not stupid enough to believe this is the best the arch can do. Their is a good reason that interlagos cannot be bought in stores, Amd know for a fact that they cannot sell this cpu to server maker, so they are busy working on it, i expect that it might take one or even 2 more stepping to fix this processor, the multithread performance is their so they only need to get a mature 32nm process to crank up the speeds and maintain the power consumptions. IMOarjuna1 - Thursday, October 13, 2011 - link
Reviews @ other sites like toms hardware and guru 3d are starting to make this look bad. How come everyone but Anand got to review it with watercooling?? Is this site in such bad terms with AMD?B3an - Thursday, October 13, 2011 - link
Water cooling isn't magically going to help performance or power consumption in any way so why does it matter?? When you buy this CPU it comes with air cooling, and Anand was right to use that for this review.marcelormt - Thursday, October 13, 2011 - link
http://www.tomshardware.com/reviews/does-amds-athl...Patrick: The 6000+ is the fastest Athlon 64 X2 dual core processor ever, but what happened to the FX family?
Damon: Patrick, you are right. The X2 6000+ is the fastest AMD64 dual-core processor ever... so why isn't it called FX? To answer that I have to explain what FX is all about... pushing the boundaries of desktop PCs. FX-51 did that right out of the gate, with multiple advantages over other AMD processors, and a clear lead on the competition. Move forward a bit to where AMD put high-performance, native dual-core computing into a single socket with the FX-60. Fast forward again and you see FX pushing new boundaries as "4x4" delivers four high-performance cores with a direct-connect, SLI platform that is ready to be upgraded to 8 cores later this year
Ryomitomo - Thursday, October 13, 2011 - link
I'm a little surprised you only posted Win7/Win8 comparison figures for FX-8150. It would give a much complete picture if you would also post i7-2600k Win7/Win8 comparison.czerro - Thursday, October 13, 2011 - link
I think anand handled this review fine. Bulldozer is a little underwhelming, but we still don't know where the platform is going to go from here. Is everyone's memory so short term that they don't remember the rocky SandyBridge start?