AMD's Bulldozer CPU design can process two threads quickly and concurrently in a single core.
The wait is almost over for AMD fans, and owners of Socket AM3+ motherboards with 990FX chipsets: Bulldozer CPUs will ship ‘within the next week or so
says the claim was made at the Hot Chips conference a couple of weeks ago, and has some new details and specs to tease us with.
Let’s just get the multi-layered codenames and brand names out of the way first though, to avoid confusion. The new CPU will indeed be a CPU – it uses the Socket AM3+ packaging and therefore has no on-board GPU. The overarching design of the CPU is codenamed Bulldozer, the first flavour of which will be codenamed Zambezi. The brand name of a Bulldozer-architecture CPU is FX.
A Zambezi CPU is comprised of four ‘modules’, each of which – AMD claims – contains two ‘cores’. However, as each core does share some resources with its partner, we’re unconvinced by this terminology: a core should be an independent execution unit that can accept, process and output work.
After all, the two Bulldozer ‘cores’ have to share ‘several components including a front-end (fetch and decode), floating-point unit, data prefetch unit.
’ For the record, we also refuse to refer to GPUs as having ‘cores’ rather than stream processors (much to Nvidia’s annoyance).
It’s easier to think of a module as a CPU core which has the ability to process two threads concurrently, so we’ll insist on referring to Bulldozer modules as cores. There is way more duplication of resources in a Bulldozer core than in any other CPU core we’ve seen, so the boost in multi-threaded performance is likely to be very high. Intel’s rival and seemingly inferior Hyper-Therading technology typically gives a performance boost of up to 30 per cent, depending on the workload.
ZDNet is saying that each Bulldozer core will have 2MB of Level 2 cache each, while the design itself has some new instruction sets, both common to Intel (‘SSE [version not given], encryption, and AVX for floating-point operations
’), and AMD-specific. The latter are said to ‘fill in some holes including FMA4 for HPC applications and XOP for numeric, multimedia, and audio/radio applications.
’ Bulldozer will support DDR3 memory at (official) speeds of up to 1,866MHz. There’s also new power management features and auto-overclocking tech Turbo Core.
Zambezi will use Globalfoundries’ 32nm SoI (silicon on Insulator) manufacturing process, which is no surprise, and each die is said to measure a hefty 315mm2
. Server and workstation versions of Bulldozer CPUs should ship in September.
With Sandy Bridge-E setups looking rather pricey
, and not due on sale for a little while, AMD has an opportunity to become the enthusiast’s choice in the run-up to Christmas. Do you think it’ll take that chance? Let us know in the forum