Well I've just run the benchmark suite from http://hg.python.org/benchmarks/ on a Core i5-2500K under 64-bit Linux with gcc 4.5.2, and got the following results:


Report on Linux localhost.localdomain 2.6.38.8-desktop-10.mga #1 SMP Wed Jan 25 10:17:18 UTC 2012 x86_64 x86_64
Total CPU cores: 4

### call_method ###
Min: 0.281984 -> 0.272776: 1.03x faster
Avg: 0.284389 -> 0.275780: 1.03x faster
Significant (t=34.11)
Stddev: 0.00170 -> 0.00258: 1.5137x larger
Timeline: http://tinyurl.com/bvr6vgc

### call_method_slots ###
Min: 0.284536 -> 0.266709: 1.07x faster
Avg: 0.287137 -> 0.268378: 1.07x faster
Significant (t=146.85)
Stddev: 0.00132 -> 0.00084: 1.5761x smaller
Timeline: http://tinyurl.com/c5a2exr

### call_method_unknown ###
Min: 0.282038 -> 0.267772: 1.05x faster
Avg: 0.286445 -> 0.272408: 1.05x faster
Significant (t=36.76)
Stddev: 0.00368 -> 0.00289: 1.2735x smaller
Timeline: http://tinyurl.com/d9c44cg

### call_simple ###
Min: 0.209886 -> 0.199631: 1.05x faster
Avg: 0.213417 -> 0.202189: 1.06x faster
Significant (t=34.52)
Stddev: 0.00304 -> 0.00258: 1.1775x smaller
Timeline: http://tinyurl.com/dxes8w7

### fastunpickle ###
Min: 0.400666 -> 0.417532: 1.04x slower
Avg: 0.406783 -> 0.426830: 1.05x slower
Significant (t=-21.12)
Stddev: 0.00427 -> 0.00518: 1.2148x larger
Timeline: http://tinyurl.com/c4rp95k

### formatted_logging ###
Min: 0.277797 -> 0.301302: 1.08x slower
Avg: 0.281376 -> 0.308164: 1.10x slower
Significant (t=-37.95)
Stddev: 0.00239 -> 0.00438: 1.8378x larger
Timeline: http://tinyurl.com/ck9ggaj

### iterative_count ###
Min: 0.103784 -> 0.114922: 1.11x slower
Avg: 0.105549 -> 0.117207: 1.11x slower
Significant (t=-40.04)
Stddev: 0.00140 -> 0.00151: 1.0725x larger
Timeline: http://tinyurl.com/cffbdw4

### nbody ###
Min: 0.241282 -> 0.228552: 1.06x faster
Avg: 0.247193 -> 0.233512: 1.06x faster
Significant (t=19.99)
Stddev: 0.00369 -> 0.00313: 1.1766x smaller
Timeline: http://tinyurl.com/c85oabx

### nqueens ###
Min: 0.260105 -> 0.298352: 1.15x slower
Avg: 0.263279 -> 0.303216: 1.15x slower
Significant (t=-72.55)
Stddev: 0.00220 -> 0.00321: 1.4595x larger
Timeline: http://tinyurl.com/c4w9qul

### regex_effbot ###
Min: 0.061832 -> 0.064062: 1.04x slower
Avg: 0.062817 -> 0.066098: 1.05x slower
Significant (t=-19.95)
Stddev: 0.00071 -> 0.00092: 1.2962x larger
Timeline: http://tinyurl.com/bnfh5s3

### regex_v8 ###
Min: 0.063420 -> 0.066753: 1.05x slower
Avg: 0.064579 -> 0.067768: 1.05x slower
Significant (t=-8.38)
Stddev: 0.00186 -> 0.00195: 1.0464x larger
Timeline: http://tinyurl.com/bq4uwr4

### richards ###
Min: 0.157204 -> 0.161524: 1.03x slower
Avg: 0.159884 -> 0.166099: 1.04x slower
Significant (t=-13.74)
Stddev: 0.00198 -> 0.00251: 1.2709x larger
Timeline: http://tinyurl.com/c774hmy

### silent_logging ###
Min: 0.066531 -> 0.071248: 1.07x slower
Avg: 0.068753 -> 0.073617: 1.07x slower
Significant (t=-16.43)
Stddev: 0.00133 -> 0.00162: 1.2181x larger
Timeline: http://tinyurl.com/cmg433a

### simple_logging ###
Min: 0.265349 -> 0.280200: 1.06x slower
Avg: 0.269531 -> 0.285340: 1.06x slower
Significant (t=-23.12)
Stddev: 0.00295 -> 0.00383: 1.2957x larger
Timeline: http://tinyurl.com/dytv5rs

### threaded_count ###
Min: 0.102369 -> 0.115217: 1.13x slower
Avg: 0.104309 -> 0.117157: 1.12x slower
Significant (t=-58.97)
Stddev: 0.00113 -> 0.00104: 1.0893x smaller
Timeline: http://tinyurl.com/cu4b5hn

### unpack_sequence ###
Min: 0.000044 -> 0.000051: 1.18x slower
Avg: 0.000045 -> 0.000053: 1.18x slower
Significant (t=-557.67)
Stddev: 0.00000 -> 0.00000: 1.1571x larger
Timeline: http://tinyurl.com/d822sf2

The following not significant results are hidden, use -v to show them:
fastpickle, float, json_dump, json_load, normal_startup, pidigits, regex_compile, startup_nosite.