[tsss]

Bulldozer gets too much hate IMO. Okay, the instructions per clock cycle were bad and power consumption was high but you can't forget that the FX-6300 was $100 for a >3-core chip that could be overclocked by another 0.7 GHz without issue. The price-performance ratio was better than anything Intel fielded. I'm still running it today.

[adrian_b]

Bulldozer has got a lot of hate mostly because of false advertising and because of a series of blog articles written by AMD marketing people before its launch in 2011, which created very wrong expectations about its characteristics.

The wrong expectations and false advertising have centered on the fact that the first Bulldozer was described as an 8-core CPU, which would easily crush its 4-core competition from Intel (Sandy Bridge).

What the AMD bloggers have forgotten to mention was that the new Bulldozer cores were much weaker than the cores of their previous CPU generations, being able to execute only 2 instructions per cycle, while an Intel core could execute 4 instructions per cycle (and the previous AMD cores could execute 3 instructions per cycle). So a Bulldozer core only had the performance of a single thread of the 2 threads of an Intel core, for multi-threaded tasks, with the additional disadvantage that the resources of 2 AMD cores could not be allocated to a single thread when the second core of a module was idle.

So an 8-core Bulldozer could barely match the multi-threaded performance of a 4-core Sandy Bridge, while being much slower on single-thread tasks.

If one would have known since the beginning that the Bulldozer cores had been intentionally designed to be much weaker than the old AMD cores and than the Intel cores, this would not have been a surprise and everybody for whom the price/performance ratio was more important than the performance would have been happy to buy Bulldozer CPUs.

However, after many months during which AMD claimed that their supposedly 8-core CPU will be better than any other CPU with less cores, there was a huge disappointment caused by the first tests after launch, which immediately revealed the pathetic performance of the new cores, which for single-thread tasks were much slower than the previous AMD CPUs.

So all the hate has been caused by the stupid actions of the AMD management and marketing, who lied continuously about Bulldozer, even if they should have thought that this is useless, because the independent benchmarks will reveal the truth immediately after launch.

To set correctly the expectations about Bulldozer vs. Sandy Bridge, what AMD called a 4-module 8-core CPU should have been called a 4-core 8-thread CPU, but which has dynamic allocation inside a core (module in AMD jargon) only for the FPU, while the integer resources are allocated statically. With this correct description there would have been no surprise about the behavior of Bulldozer.

A part of the hate is also due to some engineering decisions whose reasons are a mystery even now, because if you would have queried randomly a thousand of logic design engineers before 2011, all or almost all would have said that they are bad decisions, so it is hard to understand how they could be promoted and approved inside the AMD design teams.

For example, since the Opteron launch in 2003 and until Intel launched Sandy Bridge in 2011, the largest advantage in performance of the AMD CPUs was in the computations with large numbers, because the AMD CPUs could do integer multiplications much faster than the Intel CPUs.

The Intel designers have recognized that this is a problem, and during the 2006-2011 interval they have decreased every year the number of clock cycles required for operations like multiplications and divisions, so that Penryn began to approach the AMD throughput per clock cycle, Nehalem & Westmere matched the AMD throughput, while Sandy Bridge achieved a double throughput in comparison with the old AMD CPUs.

While Intel worked diligently to improve the performance of their cores, what did AMD do ?

Someone at AMD has decided for an unknown reason that there is no need for Bulldozer to keep their existing computational performance, but it is enough to have integer multipliers with a throughput equal to a half of their current throughput and equal to only a quarter of their Sandy Bridge competitor (Intel had announced much in advance, by more than a year before launch, that Sandy Bridge will double the integer multiplication throughput over Nehalem, and it was anyway an obvious trend of the evolution of their previous cores; so the higher performance of the competition could not have been a surprise for the AMD designers).

The downgraded integer multipliers have crippled the performance of the new AMD CPUs for certain applications where their previous CPUs had been the best, while enabling only a negligible reduction in the core area.

[paulmd]

price-to-performance is the last resort of a company that has failed at taking the performance crown.

Nobody cuts prices more than they have to, but everyone adjusts prices to where they need to go to sell the product. Bulldozer was priced low because it was genuine garbage, it was actually slower than Phenom in a lot of cases (which blows the "it was about price to peformance!" thing out of the water - nobody regresses performance on purpose).

(and before people wind up about the obvious counterexample: Ryzen was priced low because a 1800X was genuinely a lot slower than a 5960X in productivity tasks due to latency and poor AVX performance, and got completely smoked in gaming. If they had tried to go head-to-head with Intel at $1000 pricing they wouldn't have sold anything because it would have been a far inferior package to what Intel offered, they had to cut prices by around half to make it a compelling offering. And even then it was not that appealing compared to, say, a 5820K.)

Companies need to make enough of a showing to attract consumers but if a company prices something super aggressively, there's often a catch. And that's bulldozer in a nutshell. Oh shit the product sucks. What can we charge for a mediocre "8-core" (sorta) that underperforms the 4-core i7? Offer it at i5 pricing and see if anyone bites. If they had managed to achieve good performance, they would have priced it appropriately.

(the other thing is - people prefer to make the comparison about the FX-8350, but that's not Bulldozer, that's Steamroller. Bulldozer was the FX-8150/FX-6350, which actually did outright regress performance vs a Phenom X6, and was priced relatively steeply due to "8 real cores". Bulldozer went up against Sandy Bridge, Steamroller was more of an Ivy Bridge/Haswell competitor, and that's where prices really started to drop. It isn't a huge difference but Intel was making some progress too in those days.)

Price chart: https://www.anandtech.com/show/4955/the-bulldozer-review-amd...

[StillBored]

But as a consumer, all I really care about is price/perf (and maybe power and a few other variables). Far to much of the tech industry runs around talking about how great the top dog (this week) is because they bin, push the engineering margins and sell some golden chip that ends up being .0000001% of their product line for some crazy $$$$$.

During the early part of the bulldozer timeframe AMD could provide a competitive part of much of intel's lineup at a lesser cost. It was only at the end were they kept falling farther and farther behind that it was a problem. For a few years there, you could actually _SEE_ in intels pricing where AMD's top part was because there would be a bunch of parts all clustered below some number (say $200) and then there would be a big price jump between every part above that line.

And so AMD had a real problem when you went into the $RETAILER looking at a $600 laptop because while their laptop might have been better than the similarly priced intel, what you would hear is "amd sucks" and so people would actually pick the inferior product.

[paulmd]

sure, buy what you want, and competition certainly brings down prices, I don't disagree.

But making a low-cost product was not what AMD set out to do at the outset, so that's not really a defense of the technical flaws in Bulldozer's design. Sure, when they realized it was a trainwreck, they cut prices. Everyone does that, though, and that wasn't plan A.

Nobody is going to go through the expense of R&D and design and tapeout and then just not sell the product because it sucks/"missed expectations". You adjust the price to wherever it needs to be to sell the product.

Even in laptop the bulldozer chips were way power-hungry (actually this matters a lot more than in desktop) and just not that good a performer.

It was Intel's CEO's job to smile and sell hyper-clocked 14nm chips going against TSMC 7nm and it was AMD's CEO's job to smile and sell bulldozers going up against sandy bridge. That's what officers of the company do, even when they know it's shit. You go to war with the army you have, not the one you want, and you go to market with the product you have, not the one you want.