Tuesday, August 24th 2010

AMD Details Bulldozer Processor Architecture

AMD is finally going to embrace a truly next generation x86 processor architecture that is built from ground up. AMD's current architecture, the K10(.5) "Stars" is an evolution of the more market-successful K8 architecture, but it didn't face the kind of market success as it was overshadowed by competing Intel architectures. AMD codenamed its latest design "Bulldozer", and it features an x86 core design that is radically different from anything we've seen from either processor giants. With this design, AMD thinks it can outdo both HyperThreading and Multi-Core approaches to parallelism, in one shot, as well as "bulldoze" through serial workloads with a broad 8 integer pipeline per core, (compared to 3 on K10, and 4 on Westmere). Two almost-individual blocks of integer processing units share a common floating point unit with two 128-bit FMACs.

AMD is also working on a multi-threading technology of its own to rival Intel's HyperThreading, that exploits Bulldozer's branched integer processing backed by shared floating point design, which AMD believes to be so efficient, that each SMT worker thread can be deemed a core in its own merit, and further be backed by competing threads per "core". AMD is working on another micro-architecture codenamed "Bobcat", which is a downscale implementation of Bulldozer, with which it will take on low-power and high performance per Watt segments that extend from all-in-One PCs all the way down to hand-held devices and 8-inch tablets. We will explore the Bulldozer architecture in some detail.

Bulldozer: The Turbo Diesel Engine
In many respects, the Bulldozer architecture is comparable to a diesel engine. Lower RPM (clock-speeds), high torque (instructions per second). When implemented, Bulldozer-based processors could outperform competing processor architectures at much lower clock speeds, due to one critical area AMD seems to have finally addressed: instructions per clock (IPC), unlike with the 65 nm "Barcelona" or 45 nm "Shanghai" architectures that upped IPC synthetically by using other means (such as backing the cores up with a level-3 cache, upping the uncore/northbridge clock speeds), the 32 nm Bulldozer actually features a broad integer unit with eight integer pipelines split into two portions, each portion having its own scheduler and L1 Data cache.



Parallelism: A Radical Approach?
Back when analysts were pinning high hopes on the Barcelona architecture, their hopes were fueled by early reports suggesting that AMD was using wide 128-bit wide floating point units, leading analysts to believe that AMD may have conquered its biggest nemesis - floating point performance, in turn its pure math crunching abilities. However, that wasn't exactly to be. That's because the processor's overall number crunching abilities were pegged to its floating point performance, ignoring the integer units.



AMD split 8 integers per core into two blocks, each block having four integer pipelines, an integer scheduler for those, and an L1 Data cache. These constitute the lowest level of "dedicated components", dedicated to processor threads. There is a shared floating point unit between the two, with two 128-bit FMACs, arbitrated by a floating point scheduler. The Fetch/Decode, an L2 cache, and the FPU constitute "shared" components.



AMD is implementing a simultaneous multithreading (SMT) technology, it can split each of the "dedicated" components (in this case, the integer unit) to deal with a thread of its own, while sharing certain components with the other integer unit, and effectively make each set of dedicated components a "core" in its own merit of efficiency. This way, the actual core of the Bulldozer die is deemed a "module", a superlative of two cores, and the Bulldozer die (chip) features n-number of modules depending on the model.
So now you have a chip with eight cores with much lower die sizes and transistor counts compared to a hypothetical 32 nm K10 8-core processor. It is unclear whether AMD wants to further push down SMT to the "core" level and run two threads simultaneously over dedicated components, but one thing for sure is that AMD has embraced SMT in some form or another. In all this, the chip-level parallelism is transparent to the operating system, it will only see a fixed number of logical processors, without any special software or driver requirement.

So in one go, AMD shot up its integer performance. Either a thread makes use of one integer unit with its four pipelines, or deals with both the integer units arbitrated by the fetch/decode, and the shared FPU.

Outside the modules
At the chip-level, there's a large L3 cache, a northbridge that integrates the PCI-Express root complex, and an integrated memory controller. Since the northbridge is completely on the chip, the processor does not need to deal with the rest of the system with a HyperTransport link. It connects to the chipset (which is now relegated to a southbridge, much like Intel's Ibex Peak), using A-Link Express, which like DMI, is essentially a PCI-Express link. It is important to note that all modules and extra-modular components are present on the same piece of silicon die. Because of this design change, Bulldozer processors will come in totally new packages that are not backwards compatible with older AMD sockets such as AM3 or AM2(+).
Expectations
Not surprisingly, AMD isn't talking about Bulldozer as the next big thing since dual-core processors (something it did with Barcelona). AMD currently does have an 8-core and 12-core processors codenamed "Magny-Cours", which are multichip modules of Shanghai (4-core) and Istanbul (6-core) dies. AMD expects an 8-core Bulldozer implementation (built with four modules), to have 50% higher performance-per-watt compared to Magny-Cours.



Market Segments
As mentioned in the graphic before, AMD's modular design allows it to create different products by simply controlling the number of modules on the die (by whichever method). With this, AMD will have processors ready with most PC and server market segments, all the way from desktop PCs, enthusiast-grade PCs, notebooks, to servers. AMD expects to have a full-fledged lineup in 2011. The first Bulldozer CPUs will be sold to the server market.


Hotchips 22 Presentation by AMD on the Bobcat Architecture
Below are as-is slides from AMD's Hotchips presentation on the Bobcat architecture.
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283 Comments on AMD Details Bulldozer Processor Architecture

#1
Tatty_One
Senior Moderator
PaNic, you have made your point.... thank you, let's move back on topic now and talk about Bulldozer and try and get over obselete chipsets (or not) as the case may be...... :D I appreciate sockets are relative, lets just not harp on about rip off previous socket support.
Posted on Reply
#3
Valdez
by: wolf
show me the links. with no links your just ranting.



that link is moot, wikipedia isn't a statement from AMD, nor does the reference list show a link to AMD officially stating it will be on the AM3 socket.
Posted on Reply
#4
Atom_Anti
Ok guys, we got two important information:
-not backwards compatible with AM3,
-50% higher performance-per-watt compared to Shanghai and Istanbul.

Anyone can tell me a Corei7 or a Phenom2 how much faster than Shanghai or Istanbul?
Posted on Reply
#5
the_wolf88
Really why did AMD bring out 890fx chipset, just for the shitty 1090t it was nothing the 790fx couldn't handle. you ripped off customers and you don't have enuf to do that . i hope your shitty chip sucks.
FUCK YOU AMD
At least AMD motherboards are compatible with all their processors so I can upgrade the CPU anytime I want ! Not like Intel core ix which force you to upgrade to one generation only !
Posted on Reply
#6
WarEagleAU
Bird of Prey
I am glad they are going with a new chipset and socket. Bless them for being backwards compatible for so long. I don't mind spending more money for this new architecture. Also, according to that link for circuits?? it was saying that the new processor chipset and socket would be backwards compatible with AM3 procs, at least that is how I took it, I Could be wrong.

Cant wait to see this come out. IF it gets closer to the i7 I will be more than happy.
Posted on Reply
#7
JATownes
I understand that this was initially planned to run on AM3, but as technology advances, changes have to be made. Look at LGA1366 from Intel, it is EOL next year to make way for LGA2011. AM2+ and AM3 have had a very long run, but it is time to be replaced.

Lets face it though. If you are worried about upgrade costs, a 1090t on a CHIV will last a few more years without the need for an upgrade. And if you are one who needs the "latest and greatest" changing sockets is just a way of life. It happens, and we should be thankful it happens, or we would all still be stuck on DDR with single cores. SKT754 & SKT939 had a very short life span, and AMD rectified that (IMO) with the AM2+/AM3 socket (And the PHII with dual memory controllers). I am hopeful that their next socket will have an equally impressive life span.
Posted on Reply
#9
Valdez
by: Atom_Anti
Ok guys, we got two important information:
-not backwards compatible with AM3,
-50% higher performance-per-watt compared to Shanghai and Istanbul.

Anyone can tell me a Corei7 or a Phenom2 how much faster than Shanghai or Istanbul?
They not comparing it to shanghai and istanbul, but magny-cours which is a 8 or 12 core processor. (which is based on deneb core, like phenom II)

More details: http://products.amd.com/en-us/OpteronCPUResult.aspx?f1=AMD+Opteron%E2%84%A2+6100+Series+Processor
Posted on Reply
#10
link2009
I'm sorry admins but allowing "PaNiC"'s posts in this thread was a mistake and it has slightly reduced my respect for the site. Every other member except him are trying to contribute to the topic at hand while he is trolling everyone and insulting left and right.

There are mature people here and respect should be given to everyone.

Now to be on topic... I really hope that Bulldozer pans out to be what everyone is making it out to be, a real-world competitor to the i7 and (possibly) Sandy bridge.
Posted on Reply
#13
naram-sin
by: JATownes
I understand that this was initially planned to run on AM3, but as technology advances, changes have to be made. Look at LGA1366 from Intel, it is EOL next year to make way for LGA2011. AM2+ and AM3 have had a very long run, but it is time to be replaced.

Lets face it though. If you are worried about upgrade costs, a 1090t on a CHIV will last a few more years without the need for an upgrade. And if you are one who needs the "latest and greatest" changing sockets is just a way of life. It happens, and we should be thankful it happens, or we would all still be stuck on DDR with single cores. SKT754 & SKT939 had a very short life span, and AMD rectified that (IMO) with the AM2+/AM3 socket (And the PHII with dual memory controllers). I am hopeful that their next socket will have an equally impressive life span.
Best point regarding the backward compatibility of Bulldozer, so far. :respect:
...can't make a scene if you don't have the green... :rolleyes:
Posted on Reply
#14
PaNiC
by: link2009
I'm sorry admins but allowing "PaNiC"'s posts in this thread was a mistake and it has slightly reduced my respect for the site. Every other member except him are trying to contribute to the topic at hand while he is trolling everyone and insulting left and right.

There are mature people here and respect should be given to everyone.

Now to be on topic... I really hope that Bulldozer pans out to be what everyone is making it out to be, a real-world competitor to the i7 and (possibly) Sandy bridge.
trolling would mean i'm an intel fan boy or something, im just making my point that there was no need for the 890fx and to mislead people. like AMD did.
fact: people call me an emo first and i own a amd. im not a fanboy
Posted on Reply
#15
Valdez
by: PaNiC
trolling would mean i'm an intel fan boy or something, im just making my point that there was no need for the 890fx and to mislead people. like AMD did.
infact we have a lot of chipset we don't need... and a lot of processors, gpu-s... this market is just like this, face it.

Anyway it's your job (if you are interested) to choose the best to your needs. If you have chosen wrong, it's only your fault.
Posted on Reply
#16
Bloodcrazz
by: link2009
I'm sorry admins but allowing "PaNiC"'s posts in this thread was a mistake and it has slightly reduced my respect for the site. Every other member except him are trying to contribute to the topic at hand while he is trolling everyone and insulting left and right.

There are mature people here and respect should be given to everyone.

Now to be on topic... I really hope that Bulldozer pans out to be what everyone is making it out to be, a real-world competitor to the i7 and (possibly) Sandy bridge.
I dont think that "PaNiC" insulted anyone at all.
Im pretty sure that he was having a go at AMD not at any person.
Its called freedom of speech hence this being a FORUM.
Posted on Reply
#17
inferKNOX
by: WhiteLotus
It's your argument you google it.


If this is a new socket, wonder if they will change cooling attachment design?


And also I am loving this "modular" design, that mean they can have numerous types of the processor, all at different prices. Say a low end one wouldn't have much but a top end would have everything. Or am I missing the point?
+1!!
I really don't want to have to change from my Prolimatech Mega Shadow! Although I'm sure they'll just release a fresh retention kit for the new socket.

by: PaNiC
lolwat
Can you just quit it, we're not interested in your rant!:shadedshu
I can't believe people like you that complain about AMD's new CPU not being backward compatible, when they've been making all their others backward compatible for so long! Get over it, the world can't be on hold forever, the only way to make significant changes is to make things radically different and not backwards compatible.:nutkick:
“Man cannot discover new oceans unless he has the courage to lose sight of the shore.” -Andre Gide


This CPU sounds like it's gonna be great and I really looking forward to it!
Posted on Reply
#18
wolf
Performance Enthusiast
this thread has been going downhill since page 1.
Posted on Reply
#19
JATownes
by: PaNiC
trolling would mean i'm an intel fan boy or something, im just making my point that there was no need for the 890fx and to mislead people. like AMD did.
fact: people call me an emo first and i own a amd. im not a fanboy
Just to be clear. AMD 890FX was added to included SATA 6GBs and USB 3...IIRC, those are the only real changes, and they were needed for some people running these devices.
Posted on Reply
#20
JATownes
by: PaNiC
my rant isn't about the chip been backwards compatible its about AMD saying it's was going be and then change there mind after i pay top dollar for what is now a usless board.

please read befor you post... and yet im trolling
You could always send it to me :D
Posted on Reply
#21
PaNiC
by: JATownes
Just to be clear. AMD 890FX was added to included SATA 6GBs and USB 3...IIRC, those are the only real changes, and they were needed for some people running these devices.
usb 3 isnt native
Posted on Reply
#22
naram-sin
by: PaNiC
trolling would mean i'm an intel fan boy or something, im just making my point that there was no need for the 890fx and to mislead people. like AMD did.
That is completely untrue. Many needed 8xx chipsets, and in many cases it is these chipsests that have made way for better results of AM3 processors. Google some comparative reviews of 7xx and 8xx chipsets. And 8xx chipsets are more advanced (new tech) and have better peripheral performance than than 7xx chipsets. Especially, since 7xx are here almost since AM2 socket...

Btw, there was an "issue" with core unlocking. :D

With all of that and, as previously said, this wasn't misleading, this was just a change of plans...

Now, I'll stop MY ranting. OaO

EDIT:
by: PaNiC
usb 3 isnt native
SATAIII is.
Posted on Reply
#23
Bloodcrazz
by: inferKNOX
+1!!
I really don't want to have to change from my Prolimatech Mega Shadow! Although I'm sure they'll just release a fresh retention kit for the new socket.


Can you just quit it, we're not interested in your rant!:shadedshu
I can't believe people like you that complain about AMD's new CPU not being backward compatible, when they've been making all their others backward compatible for so long! Get over it, the world can't be on hold forever, the only way to make significant changes is to make things radically different and not backwards compatible.:nutkick:
“Man cannot discover new oceans unless he has the courage to lose sight of the shore.” -Andre Gide


This CPU sounds like it's gonna be great and I really looking forward to it!
If u read the earlier posts he was talking about AMD saying there releasing the AM3 socket on the bulldozer and AMD changed there minds.
After Millions of ppl bought AM3 socketed cpus believing they would be compatible.
And now they have changed the socket on the Bulldozer.
AMD by law have given false and misleading information regarding the Bulldozer.
Posted on Reply
#24
Valdez
by: PaNiC
usb 3 isnt native
I doesn't make any difference... oh maybe it costs 1 $ more...
Posted on Reply
#25
JATownes
I understand it is not native, but have you seen any 790FX board with it, or as it only been added to 890FX?

If you didn't need SATAIII or USB 3, why didn't you grab a 790FX board? They are AM3 as well, and "should have supported Bulldozer" too, according to your arguement. You grabbed the most expensive board out there. I made my argument, I am now done.

On-topic: Bring on BULLDOZER!!!
Posted on Reply
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