AMD fights Intel Atom: Bobcat/Bulldozer Ontario/Fusion APUs

By Richi Jennings. August 25, 2010.

AMD has new processors almost ready for release, including Ontario, part of it's anticipated Fusion line. These new system-on-a-chip designs combine CPU and GPU onto one die, using the new Bobcat architecture. Should be great for netbooks and set-top boxes. AMD also unveiled the Bulldozer architecture, for desktops, workstations and servers. In IT Blogwatch, bloggers dig into the silicon details.

Your humble blogwatcher curated these bloggy bits for your entertainment. Not to mention Dimensions...


Agam Shah journalizes:

PCs will ship ... "early next year" ... with chips code-named Ontario, which have CPUs based on AMD's new Bobcat low-power architecture ... designed for use in netbooks and ultraportable laptops that consume less power.


The Ontario chips are part of a family of chips called Fusion, which combine a [CPU] and [GPU] into one piece of silicon. The company ... will start shipping Ontario chips ahead of schedule. ... CPUs based on Bobcat will provide close to 90% of the performance of the company's processors used in mainstream PCs but occupy half the space. ... Bobcat's CPU core will be able to draw less than 1 watt of power.

  Anton Shilov has more about Bulldozer:

The Bulldozer micro-architecture ... will power the company's next-generation ... CPUs for desktops, servers and workstations. Apparently, the main goal ... was to ensure maximum sharing of resources within multi-core microprocessors to get high performance amid moderate low power and die sizes.


Cores will be able to dynamically share fetch and decode blocks, caches and other units. At least in initial designs, multi-core chips will consist of several major blocks, each of which will have two independent integer cores ... with dedicated schedulers and two 128-bit FMAC pipes with one FP scheduler. This means that each major block is ... essentially a tightly-linked dual-core microprocessor with shared fetch, decode and floating point units.

Jason Mick compares and contrasts:

Bobcat is an out-of-order CPU which should give it a performance edge over ... Atom ... Intel's otherwise similar design.


Following Intel's Nehalem (i7), Bulldozer is a more modular design. ... [But] it's opting for a two-integer core design capable of servicing two threads, with a common ... FPU between the cores. ... The dual-core module design is only 12-percent larger than a single core design. ... Other changes include a deeper pipeline and more aggressive prefetching.

Edward Chester lifts the lid:

Being as some of these new chips are more than just what we normally think of as a CPU, AMD has come up with a new name for them ... Accelerated Processing Unit (APU). ... Both designs will be the first to use AMD's new 32nm Silicon On Insulator technology, down from AMD's current 45nm tech.


Its new Bulldozer core design is a scratch build that adds the ability to process two threads simultaneously, somewhat akin to Intel's Hyper-Threading. ... Hyper-Threading uses a single execution core and just duplicates a few key elements required for scheduling, [but] AMD has added a whole second integer pipeline, essentially creating an 'almost-dual-core'.

Jon "Hannibal" Stokes digs in to Bulldozer:

AMD's official line on Bulldozer is that it's a "third way" between traditional multicore and simultaneous multithreading (SMT). ... SMT essentially keeps two or more threads loaded into the processor, and the machine's execution hardware switches between them dynamically. ... [So] if one thread stalls while waiting on main memory, there are instructions from a different, non-stalled thread right there in the machine that can be immediately executed without any kind of context switch. ... [But] SMT adds a bit to a processor's die area and power budget.


AMD claims that in the real world, a single two-way SMT core works as well as 1.3 regular cores ... only in very ideal scenarios is an SMT core not bottlenecked. ... Bulldozer isn't "dual-core" in any real sense—it's more like a 1.5-core design, whereas a conventional SMT processor core is really a 1.2-core design. ... [It] will perform much better than a regular SMT design, but at the cost of a ton of additional, very power-hungry integer execution hardware.

And Anand Lal Shimpi purrs over Bobcat:

Ever since the Pentium Pro (P6), we have been blessed with out of order microprocessor architectures ... which let you schedule independent instructions ahead of others. ... When Intel designed the Atom processor it went back to an in-order design as a way of reducing power. ... AMD’s opportunity to innovate is clear.


Bobcat is a fully out of order architecture ... [which] should provide a healthy single threaded performance boost over Atom. ... Bobcat (as well as Bulldozer) uses physical register files to save power. ... a dual core Ontario based on Bobcat, if clocked high enough, could deliver a good enough balance of single and multithreaded performance to really challenge Atom.


And Finally...

How Big Really? [hat tip: Ms. Fix-It]
[for "postcode" you may prefer to think "zip code"] 

Don't miss out on IT Blogwatch:

Richi Jennings, your humble blogwatcher
  Richi Jennings is an independent analyst/consultant, specializing in blogging, email, and security. A cross-functional IT geek since 1985, you can follow him as @richi on Twitter, pretend to be richij's friend on Facebook, or just use good old email:

You can also read Richi's full profile and disclosure of his industry affiliations.

Copyright © 2010 IDG Communications, Inc.

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