AMD FX-8150 8-Core CPU Review: Bulldozer Is Here - HotHardware

AMD FX-8150 8-Core CPU Review: Bulldozer Is Here

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As we mentioned on the previous page, we won’t be rehashing many of the low-level technical details of AMD’s Bulldozer microarchitecture here, since we’ve already covered them in previous articles. We will, however, cover more product specific details and offer up a condensed refresher of some of the details presented in our previous Bulldozer-related coverage.


AMD FX-Series Processor Die Map

What you see here is a die map of an AMD FX-Series, 8-core die, formerly codenamed “Zambezi”. It is comprised of roughly 2 billion transistors, is approximately 315mm2,  and is manufactured using Global Foundries’ 32nm DSL SOI (silicon-on-insulator) technology. At 315mm2, the Zambezi core used in the FX is somewhat than Thuban's (Phenom II X6) 346mm2, which is good for AMD, but it's still much larger than Sandy Bridge's approximate 216mm2. There is 128 KB of L1 Data Cache (16KB per core), 256 KB of L1 Instruction Cache (64KB per module), and 8MB of L2 Cache (2MB per module), along with 8MB of shared L3 cache. There are four 16-bit HyperTransport links present, although only one is enabled on desktop Bulldozer processors, the others are present for server-class products which are based on the same core design. There is also an Integrated memory controller / northbridge which features two, 72-bit wide DDR3 memory channels.

AMD refers to Bulldozer’s design as a third-way between symmetric multithreading (SMT) like Intel’s Hyper-Threading and true multi-core processing, where multiple discrete cores reside on one die. With Bulldozer, AMD started with two discrete cores, and eliminated some duplicate logic that may have gone unused with the vast majority of workloads. AMD then fused the resulting, pared down cores together into a single, shared design. As far as design efficiency was concerned, taking this route was fruitful as Bulldozer's second ALU unit increased the die size by only 12%. AMD has also emphasized the point that Bulldozer has been architected to be power-efficient. The design features extensive clock-gating throughout, numerous circuits that can be power-gated dynamically, and multiple power-saving features that are under software control (C6 State, Core P-states / AMD Turbo Core, APM, DRAM power management, low power idle state, and C1E).


AMD Bulldozer "Two-Core" Module

With Bulldozer, AMD has taken the concept of SMT and essentially added a second independent integer unit. Intel's Hyper-Threading technology improves core efficiency by scheduling multiple threads for simultaneous execution. In a situation where the processor is waiting for code from Thread A, the scheduler can send work for Thread B. This keeps the processor's execution units more fully utilized for longer periods of time, but Hyper-Threading doesn't provide the CPU with any additional execution resources. According to AMD, the company aggressively researched which core blocks needed to be duplicated and which could be combined before finalizing the design of Bulldozer. As far as the OS is concerned, however, each Bulldozer module will appear as a dual-core processor, just as an Intel Hyper-Threaded processor is shown to have double the actual number of actual physical cores.

We should also point out that Bulldozer has four x86 decoders, whereas previous AMD products had just three. And Bulldozer's branch predication units have been optimized for for high performance as well. In fact, branch prediction and instruction fetch logic has been decoupled, which means that an incorrect branch prediction won't stall the fetch unit (and vice versa). Phenom doesn’t have this ability, because the two units are tied to each other.

Bulldozer’s joint FPU unit is capable of tracking two hardware threads (one from each core) and has two MMX integer units and two 128-bit FMAC units. Bulldozer also adds support for SSE4.1, SSE4.2, AVX, AES, in addition to FMA4 and XOP extensions, though software will have to be specifically coded to leverage these resources.

AMD is positioning the FX series at the top of its desktop processor line-up. The E-Series Accelerated Processing Units (APU) are designed for low-power, small form factor, and mobile applications. AMD A-Series APUs are designed for mobile and mainstream desktop applications. And the FX Series is designed for performance-minded consumers and enthusiasts. The feature breakdown above explains what type of workloads each APU / CPU series targets, but it should be noted that there’s nothing stopping a user from plunking a discrete Radeon graphics card into an E- or A-Series APU based system and taking advantage of AMD Eyefinity technology.

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Good to see this thing finally land. Even though it didn't cream the 2600K like people thought it would, it's still a strong performer in it's own right.

I guess now it's up to AMD to make this CPU ~a very compelling buy~ to ensure it's success. If the price to performance ratio is good enough compared to Intel's offerings, it will sell.

The only thing about this beast that gives me pause is the amount of power that it consumes, and the heat that it will certainly generate. (I have a 2600K now that is fast, efficient, and runs cool)

I'm going to wait for a while before I buy into anything. I'm sure that some sort of response is imminent from the boys in blue, and I want to see what that is. Plus, the prices of these Bulldozers will probably come down before too long. Now may not be the best time to buy one.

I thought that this review was a good read, and I stayed up late just to read it all before I went to sleep. I waited until now to comment though. (I couldn't stay awake last night) Good job on the review Marco, as always.

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I wont lie, im happy and a bit sad all at once. Good to see AMD finally releasing this thing, its about time! However, the performance is a bit disappointing, hopefully it will indeed get better in the future with windows 8 and maybe an update to windows 7? Either way, my next comp is a laptop and it will be trinity so im curious to see how piledriver cores will improve upon what ive seen here today. Either way, Congrats AMD! And thanks to Hothardware and Marco for the article!

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Thanks for the review Marco! I'm a little bummed about the performance and power consumption but it still looks like a good chip at an affordable price; which we all expected. Looking forward to seeing some more builds with this! 8 cores......crazy!

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"Oh boy. Well , it did not turned out As I predicted, but it still a good chip. I did some analysis and I came to the conclusion that  AMD needs to price the 8150 equally to SB 2500k, had it been so from the beginning, then the reviews all across the board would have been more favorable. I see a little of Intel's *Speed/Price* ratio pricing of the X58 chips, specifically from the 920 all the way up to the 960. Its the same exact chip but clocked at different *stock* speeds and price. So what do I mean by all of this, well, the 8120 is the same as the 8150, only one is clocked higher then the other so, I would rather save me $60 and go for the 8120 and just have it overclocked to the same overclock speeds that the 8150 can reach."

http://www.newegg.com/Product/Product.aspx?Item=N82E16819103960

"Can't deny that the hype has turned negative for AMD. The average consumer is saying why can't an  8 core beat a 4 core? Why the FX brand, why so much delay for such little gain over the Phenoms. Its safe to say AMD did not deliver but, ultimately, it's not bad, just need better pricing."

"Anyone catch the name scheme in the roadmap?, Bulldozer - PileDriver - SteamRoller - Excavator. ROFL, someone over at AMD sure loves construction equipment, its like with Nvidia and Comic books characters, Ka-lel  - Wayne - Logan - Starks, lol. "

"Anyhow, Marco , is there a separate Bulldozer vs Sandy Bridge Gaming analysis and review coming? Maybe Joel H is working on it?"

 

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Wheatley:
I did some analysis and I came to the conclusion that  AMD needs to price the 8150 equally to SB 2500k, had it been so from the beginning, then the reviews all across the board would have been more favorable.

*slaps head profuriously hard*

Intel Core i5 2500k: $218

AMD FX-8150: $245

I know it's only the suggested retail price but there is only a marginal difference between the price points, so I doubt that it would favor in better reviews. If you really did the research, you would of discovered this: http://www.legionhardware.com/articles_pages/amd_fx_8150fx_8120fx_6100_and_fx_4170,1.html

Also I'd wait a while before making a judgement about the prices, I mean alot of retailers are inflating the prices beyond their suggested prices and I don't know why they're doing it but it just ain't right...

Wheatley:
So what do I mean by all of this, well, the 8120 is the same as the 8150, only one is clocked higher then the other so, I would rather save me $60 and go for the 8120 and just have it overclocked to the same overclock speeds that the 8150 can reach."

So why are you making a big point of an obvious thing that everybody knows? You even said this before in one of your posts; as much as I share your opinion, stating it as a point just doesn't help you in any way.

Wheatley:
"Can't deny that the hype has turned negative for AMD. The average consumer is saying why can't an  8 core beat a 4 core? Why the FX brand, why so much delay for such little gain over the Phenoms."

Didn't you read the article? I read it page to page, detail to detail. The bulldozer-module is a combination of multi-threading and hyper threading. Which means that there are really only 4 cores (modules) and the rest is emulated with hyper-threading... Hence the comment about the 12 core CPU (12 equaling 6 Bulldozer Modules.)

Also: [View:http://www.youtube.com/watch?v=9vQaVIoEjOM]

So yeah... Bulldozer managed to near the i5-2500k at some things but to not match the i7-2600k is disappointing. The price thing is overblown though.

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I did read the AMD FX 8 cores CPU. I was somewhat impressed with its performance. Let's wait for Intel release new powerful processor soon.

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I have been eagerly waiting for this CPU to come out and now I'm deeply disappointed... That thing could bearly compete with the core i5. I'm sure if AMD made and 8 core phenom processor it would perform just as good...

I do understand the challenges that AMD has been facing all these years being the competitor of a dominant monopolistic and resourceful giant like Intel but this is really dispiriting...

I really hope they get their rear in gear and come up with more efficient and competitive chip designs.

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Nice review Marco. I liked how you hit all of the points that people want to hear about, such as how the processor performs in certain citations.

I'm guessing I was right in the fact that Bulldozer would match Intel's processors. I mean even if it didn't beat Intel, it still performed relatively close to them (i7 not included) and if they manage to get their stuff together for next year then maybe it could possibly beat the newer SB-E processors, maybe...

The fact that the CPU didn't perform as they expected however is going to disappoint a few fans who were anticipating Bulldozer though, me included. I mean I've seen a video of some form of Bulldozer powering a game while allowing multi-tasking to happen and while the same may apply here, it just doesn't seem to be the Intel crushing monster that it was hoped to be...

I was surprised that the thing used a combine method of Hyper Threading and true cores. (Kinda makes me wonder how a 12 core Bulldozer processor would perform) I mean I knew that they had some form a method that allowed them to have 8 cores with 4 modules but I didn't expect it to be this. In any case, historically AMD's methods of producing processors have always lead to questionable performance as time goes on. I mean we have Intel focusing heavily on x86 performance and with the lead they have in silicon dies... There's just no question who dominates here.

Anyways, the methods they've used has always resulted in less then expected performance for those users who used their processors, even though some don't mind the performance drop. While they may have found a way that could at least best Intel at some parts, the applications for which it was put through placed less then expected performance results. Like the computer was giving it instructions and the processor just knew exactly what to do but didn't know the most efficient way to do it; this has historically been AMD's weakness; they do seem to be putting improvement with Bulldozer but it's still a weakness.

Despite that, No one can deny that the confidence that AMD had in this processor was justified and again, bringing back the FX brand is a vote of confidence that AMD was working hard to put out a competitive processor that can compete with Intel's 5-series CPU's. And did you see the slides leaked from AMD presentations that detailed how the processor could be powerful under certain situations due to the Bulldozer module that they made for the CPU; and you can't forget about that AMD belt that was seen just a few days. Even though the performance of the processor was disappointing to some, you can't deny that AMD didn't convince customers that their processor would at least not be a Phenom II X4.

So aside from that; yeah... This is Bulldozer in all it's glory. I wasn't following much on Bulldozer due to my lack of interest in upgrading the system but from what I've read, it's competitive, it's cheap (okay, it's $50 more expensive but the fact that it matches Intel at certain parts makes it more viable to those looking for an Intel alternative without the really crappy performance.) and even though they couldn't take advantage of the 32nm process (power consumption for example.) they have managed to make a competitive processor and a jumping pad for future AMD processors should they feel the heat from the SB-E processors that'll be released earlier that'll be certain to blow most of the Bulldozers out of the water but at a high-cost.

Good job AMD! Good job!

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It will be interesting to see the power numbers for the 95W 8 core part the 8120(?). The one things that I look at negatively is the huge differential in the idle and under full load power draws.. At this state of the AMD CPU front I'm thinking the Daneb's still give the best bang for your buck.

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Disappointing performance considering all the hype!

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