Distributed.net

Tested speeds

x86/ELF Client

Intel Pentium 4 3.2GHz

Single Socket system (1 core)

[Feb 19 17:40:49 UTC] RC5-72: Completed CC:674C8FC3:00000000 (1.00 stats units)
                      0.00:11:50.72 - [6,043,121 keys/s]

AMD64 Client

AMD Opteron 6174

Dual Socket system (24 cores)

[Feb 19 16:43:25 UTC] RC5-72: Summary: 24 packets (24.00 stats units)
                      0.00:08:17.84 - [198.32 Mkeys/s]

As a note, dnetc was not able to detect the processor properly because it is a preproduction:

[Feb 19 16:35:07 UTC] Automatic processor type detection did not 
                      recognize the processor (tag: "40010001")

AMD Opteron 8435

Quad Socket system (24 cores)

[Feb 19 16:16:40 UTC] RC5-72: Summary: 24 packets (24.00 stats units)
                      0.00:12:18.67 - [139.55 Mkeys/s]

AMD Opteron 2356

Dual Socket system (8 cores)

[Feb 19 17:07:48 UTC] RC5-72: Summary: 16 packets (16.00 stats units)
                      0.00:12:19.47 - [72.86 Mkeys/s]

AMD Opteron 275

Dual Socket system (4 cores)

[Feb 19 17:17:58 UTC] RC5-72: Summary: 8 packets (8.00 stats units)
                      0.00:07:22.31 - [34.73 Mkeys/s]

AMD Opteron 875

Quad Socket system (8 cores)

[Feb 19 17:35:08 UTC] RC5-72: Summary: 12 packets (12.00 stats units)
                      0.00:15:16.32 - [53.65 Mkeys/s]

AMD Opteron 250

Dual Socket system (2 cores)