More basic benchmarks (stress running -c - which apparently computes sqrt() at some rate):

# stress -t 30s -c 8 -m 1 && cat /proc/loadavg
stress: info: [6975] dispatching hogs: 8 cpu, 0 io, 1 vm, 0 hdd
stress: info: [6975] successful run completed in 30s
3.64 1.23 0.53 1/47 6985
# cat /proc/cpuinfo 
Processor       : Feroceon 88FR131 rev 1 (v5l)
BogoMIPS        : 1192.75
Features        : swp half thumb fastmult edsp 
CPU implementer : 0x56
CPU architecture: 5TE
CPU variant     : 0x2
CPU part        : 0x131
CPU revision    : 1

Hardware        : Marvell RD-88F6281 Reference Board
Revision        : 0000
Serial          : 0000000000000000

$ stress -t 30s -c 8 -m 1 && cat /proc/loadavg 
stress: info: [10077] dispatching hogs: 8 cpu, 0 io, 1 vm, 0 hdd
stress: info: [10077] successful run completed in 30s
3.78 1.28 0.85 1/126 10087
$ cat /proc/cpuinfo 
processor       : 0
vendor_id       : AuthenticAMD
cpu family      : 5
model           : 10
model name      : Geode(TM) Integrated Processor by AMD PCS
stepping        : 2
cpu MHz         : 498.091
cache size      : 128 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 1
wp              : yes
flags           : fpu de pse tsc msr cx8 sep pge cmov clflush mmx mmxext 3dnowext 3dnow
bogomips        : 996.18
clflush size    : 32
cache_alignment : 32
address sizes   : 32 bits physical, 32 bits virtual
power management:

The Marvell board has a 1200Mhz X-Scale (ARM5) versus the AMD Geode (x86) 500Mhz. With about the same amount of RAM (some more things are running on the Geode device) the ARM board appears to win. But not by much; and this is supposedly a fast ARM board. I'm very curious about a Cortex-A8 to see how that does, but I don't have a beagleboard to test on.

Oh, but wait...

$ stress -t 30s -c 8 -m 1 && cat /proc/loadavg
stress: info: [20281] dispatching hogs: 8 cpu, 0 io, 1 vm, 0 hdd
stress: info: [20281] successful run completed in 30s
4.00 0.99 0.32 1/231 20291
$ cat /proc/cpuinfo 
processor       : 0
vendor_id       : AuthenticAMD
cpu family      : 15
model           : 67
model name      : AMD Athlon(tm) 64 X2 Dual Core Processor 6000+
stepping        : 3
cpu MHz         : 2992.907
cache size      : 1024 KB
physical id     : 0
siblings        : 2
core id         : 0
cpu cores       : 2
apicid          : 0
initial apicid  : 0
fpu             : yes
fpu_exception   : yes
cpuid level     : 1
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov 
pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt rdtscp lm 3dno
wext 3dnow rep_good extd_apicid pni cx16 lahf_lm cmp_legacy svm extapic cr8_lega
cy
bogomips        : 5985.81
TLB size        : 1024 4K pages
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management: ts fid vid ttp tm stc

processor       : 1
vendor_id       : AuthenticAMD
cpu family      : 15
model           : 67
model name      : AMD Athlon(tm) 64 X2 Dual Core Processor 6000+
stepping        : 3
cpu MHz         : 2992.907
cache size      : 1024 KB
physical id     : 0
siblings        : 2
core id         : 1
cpu cores       : 2
apicid          : 1
initial apicid  : 1
fpu             : yes
fpu_exception   : yes
cpuid level     : 1
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov 
pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt rdtscp lm 3dno
wext 3dnow rep_good extd_apicid pni cx16 lahf_lm cmp_legacy svm extapic cr8_lega
cy
bogomips        : 5985.51
TLB size        : 1024 4K pages
clflush size    : 64
cache_alignment : 64
address sizes   : 40 bits physical, 48 bits virtual
power management: ts fid vid ttp tm stc

So it just goes as fast as it can. WTF is the point of stress again?