With the sun now setting on the IDF tech jamboree in Beijing, Intel has released some spectacular performance figures for its upcoming family of 45nm PC processors, codenamed Penryn. The impressive new numbers are just the latest salvo in the ongoing PR battle between Intel and arch rival AMD in the run up to the launch of new processors from both companies later this year.

The benchmark results cover both the 6MB cache dual-core and 12MB cache quad-core variants of the Penryn family, known internally at Intel as 'Wolfdale' and 'Yorkfield', respectively. Both chips sport a clockspeed of 3.33GHz and benefit from a faster 1,333MHz bus frequency.

To put the performance of the upcoming CPUs into context, Intel also dished out comparative numbers from the current flagship of the Core 2 range, the new 2.93GHz QX6800 Core 2 Extreme chip. For the record, that's a quad-core processor based on a pair of dual-core Conroe (Core 2) cores sharing a 1,066MHz bus and boasting a combined 8MB of cache memory. It also happens to be comfortably the fastest currently available PC processor, by many metrics, and is a particularly lethal weapon for multi-threaded software.

Superficially, the new Penryn architecture is largely a 45nm die shrink of that wildly successful 65nm Conroe design. However, along with the increased operating frequency allowed by the finer 45nm production process, Intel claims a number of detail enhancements deliver a significant kick to clock-for-clock performance. Most notably, in terms of desktop performance, is the latest revision of Intel's multimedia-friendly streaming SIMD instruction sets, known as SSE4.

The results, if Intel's numbers are to be believed, are pretty spectacular. No doubt courtesy of those new SSE instructions, the new quad-core chip is over twice as fast the existing QX6800 processor in DivX video encoding (note the test was conducted with an alpha build of DivX 6.6).

The performance boost in Valve Software's popular 3D shooter, Half-Life 2, is a more typical 37 per cent. Not quite as sensational as the DivX benchmark, perhaps, but still well ahead of the 14 per cent increase in core clockspeed. Intel also provided results for H.264 video encoding, Cinebench and 3DMark06. See the full results table by clicking through to the second picture above.

Of course, these Intel-produced numbers are no doubt carefully selected to show the new architecture in the most favourable light possible. But it must still make for uncomfortable reading for AMD engineers.

The big question, therefore, is whether AMD's fancy new 65nm quad-core processor architecture , codenamed Barcelona, can possibly compete with Intel's upcoming 45nm killer. AMD has been busy raising expectations for Barcelona in recent months and has been happy to claim the new chip will be a performance leader at launch in the second half of 2007. However, it's not clear whether AMD's claims factor in the improved performance of the Penryn architecture or merely make comparison to existing Conroe Core 2 processors.

What's more, the technical details AMD has so far released indicate a similar approach to the current Core 2 design, including improved floating point throughput and a focus on increased IPC (instructions per clock), rather than a radical Conroe-crushing design. Current rumours also suggest Barcelona will top out at just 2.5GHz at launch.

But there is a glimmer of hope for AMD. The new Penryn-class processors retain Intel's rather creaky and dated front side bus CPU I/O technology. Intel has also confirmed that quad-core Penryn CPUs will remain dual-die designs - in other words, a pair of dual-core chips packed onto the same processor package. All of which means that bus traffic and memory latency will remain a weakness, despite the increased FSB frequency.

By contrast, AMD's Barcelona architecture is a true single-die, quad-core design which benefits from superior I/O bandwidth and latency thanks to its on-chip core-to-core communications and on-die HyperTransport I/O. And that should give AMD an advantage in terms multi-core performance scaling. Barcelona might just give Penryn a scare, after all, even if it can't match it on a core-for-core or clock-for-clock performance basis.

Whatever happens, keep your browsers tuned to Tech.co.uk. When AMD and Intel finally release these new processors later this year, it's going to be a titanic contest.