The intel xeon L5410 is a nice chip. It combines power with efficiency, includes multiple cores, as well as some impressive cache. In my server setup, I've combined it with a [http://www.my-tech-deals.com/blog/2008/07/14/new-server/ SUPERMICRO X7DAE-O Dual LGA 771 Intel 5000X motherboard]].
The motherboard BIOS are smart enough to support the power saving capabilities of the Xeon, so it has access to C-States AND frequency modulation.
Base cpuinfo
cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 23 model name : Intel(R) Xeon(R) CPU L5410 @ 2.33GHz stepping : 6 cpu MHz : 2000.000 cache size : 6144 KB physical id : 0 siblings : 4 core id : 0 cpu cores : 4 fdiv_bug : no hlt_bug : no f00f_bug : no coma_bug : no fpu : yes fpu_exception : yes cpuid level : 10 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc arch_perfmon pebs bts pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr dca sse4_1 lahf_lm bogomips : 4670.36 clflush size : 64
Powertop Results w/ 2.6.25
PowerTOP version 1.10 (C) 2007 Intel Corporation
Cn Avg residency P-states (frequencies)
C0 (cpu running) ( 0.1%) 2.34 Ghz 0.0%
polling 0.0ms ( 0.0%) 2.00 Ghz 100.0%
C1 0.0ms ( 0.0%)
C2 0.0ms ( 0.0%)
C3 266.0ms (99.9%)
Wakeups-from-idle per second : 3.8 interval: 5.0s
no ACPI power usage estimate available
Top causes for wakeups:
19.7% ( 2.4) : queue_delayed_work_on (delayed_work_timer_fn
16.4% ( 2.0) : clocksource_register (clocksource_watchdog)
16.4% ( 2.0) : extra timer interrupt
11.5% ( 1.4) : eth0
8.2% ( 1.0) : edac_pci_add_device (delayed_work_timer_fn)
8.2% ( 1.0) : edac_mc_add_mc (delayed_work_timer_fn)
Nice, huh?