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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AmdInside - Wednesday, October 12, 2011 - link
Their roadmap is aggressive but when is the last time AMD has come close to meeting their schedule? Not going to happen. But do hope that they do for consumers sake.Eagle70ss - Wednesday, October 12, 2011 - link
AMD really bent over and grabbed their ankles....I'm just wondering why it took so long to release douche-dozer...I was really hoping they would have a good part this time...Will Intel stand alone as the sole quality CPU maker?? Only time will tell, but it looks to be so....silverblue - Wednesday, October 12, 2011 - link
I must say, I did expect this. That price drop wasn't exactly a giveaway, was it? Single threaded performance is generally poor and there really is something wrong with the caching. I simply refuse to believe a lack of BIOS optimisations is at fault for any of this... and blaming Windows 7 for not truly understanding Bulldozer's idiosyncracies? Come off it; Windows 8 won't even be around when Piledriver appears, and we'll have to wait to see the second generation of this particular microarchitecture performing more like it "should". Bringing back the FX moniker certainly attracted attention, however if by doing so they wanted to remind us of the fact that the FX-51 was a server CPU, they've succeeded, if only on that basis, as the FX was king of all and not just in select benchmarks as the P4 tended to be.I can't wait for Johan's server review; I just want to see if this thing really does well in its natural habitat. It's got to have a success somewhere. Thankfully, I can see far more optimism in this area. Incidentally, I was expecting Bulldozer to be able to work on eight 128-bit FP instructions per clock as opposed to 6 with Thuban, so obviously I got my wires crossed on that one.
You can't argue that Bulldozer hasn't a lot of promise, but at the same time, you can't argue that AMD haven't been trying to perform damage limitation on an already faulty product.
arjuna1 - Wednesday, October 12, 2011 - link
Nobody, and I mean, nobody at all, expected Bulldozer to reach SB like performance, obvious nobody either saw sub Phenom II performance in certain applications, but almost everything promised has been delivered, at lower prices than Intel, the way AMD has always done it, and quoting the article:"In many ways, where Bulldozer is a clear win is where AMD has always done well in: heavily threaded applications. If you're predominantly running well threaded workloads, Bulldozer will typically give you performance somewhere around or above Intel's 2500K."
PS
wolfman3k5, stop your Intel shilling, it almost look like if Intel was paying you by the hour.
wolfman3k5 - Wednesday, October 12, 2011 - link
I get $22.50 per hour from Intel plus tips. I also get a $50.00 bonus if I surpass 1000 comments / posts per day. Between 3:00AM and 7:00AM I get $25.85 per hour. I make good money writing nice things about Intel. What do you do?g101 - Wednesday, October 12, 2011 - link
What's surprising is that you apparently think that's "good money".Guess what, you little dumbshit kid, profit savvy professionals will sill be running AMD. I couldn't care less about your shitty lightly threaded games and optimized synthetic benchmarks.
Stupid children using their computers for play.
silverblue - Friday, October 14, 2011 - link
You need to bear in mind that a) AMD reintroduced the FX brand just for Zambezi, and b) JF-AMD actually started a thread entitled The Bulldozer Blog Is Live! on www.overclock.net. Regardless of whether John Freuhe is a server-focused guy or not, the point being is that he and AMD both targetted the client side in terms of i) overclockers and ii) gamers. I might be wrong, but that's how I see it. Yes, he didn't come out and say it directly that Zambezi would be a great gaming solution, but he DID say that IPC would be an improvement over their past products. Now that the reviews are out, he's nowhere to be seen, barring the odd login to do who-knows-what. Does overclock.net have any leaning towards the server market in any way?If Zambezi's poor performance is partly down to using faulty ASUS boards/anything less than 1866MHz RAM/an L1 cache bug/some weird hardware combinations/WHATEVER, I'm sure we'll find out in time, but regardless, it's going to be harming non-gaming workloads as well, so it's important to people like you as well.
silverblue - Friday, October 14, 2011 - link
Just thought I'd say that I've been a bit harsh to JF there. Out of all the AMD people who could've come along to have a chat, he was definitely the bravest. It was on his free time, and he's probably getting copious amounts of hate messages just for being an AMD rep.Proxicon - Wednesday, October 12, 2011 - link
I stayed up all night to read this review....I guess the prices on 2600k won't be going down anytime soon. I had already built my complete system in my head. Then the reviews came..
I kind of figured that if AMD was firing people and resignations were being handed in before a major launch, it wasn't going to be good. Also, no early release of benchmarks. That in itself was suspect. If they really had such a great processor than why all the secrecy. I was hoping it was an Apple play. boy, was I wrong.
You guys buy the "faildozer" and help keep the prices of the 2600K low. I'll be looking for a 2600K....
3DVagabond - Wednesday, October 12, 2011 - link
I'm not an expert, but Bulldozer seems to be a server chip pressed into desktop service. Designed for highly threaded workloads many consumer tasks just aren't it's forte (and also designed to have even more cores than 8). While it isn't competitive in single thread performance, if you use highly threaded workloads enough and aren't afraid to O/C to boost the single core performance, Bulldozer can be the better chip. That is if the price is right. The 8120 might be an awesome value in this scenario. We'll have to wait for reviews to be sure.One question, please. When you O/C'd the 8150, did you only use stock cooling? From the review it sounded like you did, but instead of saying so clearly, you said it wouldn't do 5GHz on "air" (I believe that was the statement? Feel free to flame me if I'm wrong. :D). So, to be clear, would it not do 5GHz on air with a top notch cooler, or did you only try the stock cooler?
Thanks.