Intel has released additional information on preliminary Penryn performance figures. These benchmark results haven't been independently verified, so they should be taken with a grain of salt. However, since the Core 2 Duo certainly lived up to expectations set by preliminary benchmarks, perhaps only a grain is necessary.

According to Intel, Penryn performance was tested on a pre-production BadAxe2 motherboard with a dual-core Wolfdale chip with 6MB of cache and a quad-core Yorkfield chip with 12MB of cache. Both chips ran at 3.33GHz on a 1333MHz front-side bus. For comparison, Intel has included results from a Core 2 Extreme QX6800 running at 2.93GHz on a 1066MHz front-side bus. Intel says test systems were otherwise configured with identical hardware, including a GeForce 8800 GTX graphics card, 2GB of DDR2-800 memory with 5-5-5-15 timings, and a 32-bit version of Windows Vista Ultimate, yielding the following results. The Divx and H.264 encoding scores are in seconds, so lower is better. The quad-core Penryn's performance advantage over the current QX6800 ranges from just over 7% in 3DMark06's overall score to a stunning 53% in the Divx encoding test. Penryn is working with a faster front-side bus and processor clock, of course, but it's unlikely the extra MHz alone accounts for the 18-25% performance advantage Penryn enjoys through the bulk of Intel's results.