"однояцевый" atlon 2x :( [FOUND :)]

"потерялось" одно "яйцо" :(. причем на ходу. т.е. поменять настройки где-либо было затруднительно. :) просто почувствовал после обеда, что производительность ощутимо подсела. с утра было два, теперь одно...
dmesg:

.........skip..........
mapped APIC to ffffb000 (fee00000)
mapped IOAPIC to ffffa000 (fec00000)
Enabling fast FPU save and restore... done.
Enabling unmasked SIMD FPU exception support... done.
Initializing CPU#0
PID hash table entries: 2048 (order: 11, 8192 bytes)
Detected 2100.156 MHz processor
.........skip.........
SLUB: Genslabs=22, HWalign=64, Order=0-1, MinObjects=4, CPUs=2, Nodes=1
.........skip.........
CPU: After generic identify, caps: 178bfbff ebd3fbff 00000000 00000000 00002001 00000000 0000011f 00000000
CPU: L1 I Cache: 64K (64 bytes/line), D cache 64K (64 bytes/line)
CPU: L2 Cache: 512K (64 bytes/line)
CPU 0(2) -> Core 0
CPU: After all inits, caps: 178bfbff ebd3fbff 00000000 00000410 00002001 00000000 0000011f 00000000
Intel machine check architecture supported.
Intel machine check reporting enabled on CPU#0.
.........skip.........
SMP alternatives: switching to UP code
.........skip.........
CPU0: AMD Athlon(tm) 64 X2 Dual Core Processor 4000+ stepping 01
SMP alternatives: switching to SMP code
Booting processor 1/1 eip 3000
Not responding.
Inquiring remote APIC #1...
... APIC #1 ID: 1000000
... APIC #1 VERSION: 80050010
... APIC #1 SPIV: ff
CPU #1 not responding - cannot use it.
Total of 1 processors activated (4202.57 BogoMIPS).
.........skip.........

ядро:

#
# Processor type and features
#
CONFIG_TICK_ONESHOT=y
CONFIG_NO_HZ=y
CONFIG_HIGH_RES_TIMERS=y
CONFIG_SMP=y
CONFIG_X86_PC=y
# CONFIG_X86_ELAN is not set
# CONFIG_X86_VOYAGER is not set
# CONFIG_X86_NUMAQ is not set
# CONFIG_X86_SUMMIT is not set
# CONFIG_X86_BIGSMP is not set
# CONFIG_X86_VISWS is not set
# CONFIG_X86_GENERICARCH is not set
# CONFIG_X86_ES7000 is not set
# CONFIG_PARAVIRT is not set
# CONFIG_M386 is not set
# CONFIG_M486 is not set
# CONFIG_M586 is not set
# CONFIG_M586TSC is not set
# CONFIG_M586MMX is not set
# CONFIG_M686 is not set
# CONFIG_MPENTIUMII is not set
# CONFIG_MPENTIUMIII is not set
# CONFIG_MPENTIUMM is not set
# CONFIG_MCORE2 is not set
# CONFIG_MPENTIUM4 is not set
# CONFIG_MK6 is not set
# CONFIG_MK7 is not set
CONFIG_MK8=y
# CONFIG_MCRUSOE is not set
# CONFIG_MEFFICEON is not set
# CONFIG_MWINCHIPC6 is not set
# CONFIG_MWINCHIP2 is not set
# CONFIG_MWINCHIP3D is not set
# CONFIG_MGEODEGX1 is not set
# CONFIG_MGEODE_LX is not set
# CONFIG_MCYRIXIII is not set
# CONFIG_MVIAC3_2 is not set
# CONFIG_MVIAC7 is not set
CONFIG_X86_GENERIC=y
CONFIG_X86_CMPXCHG=y
CONFIG_X86_L1_CACHE_SHIFT=7
CONFIG_X86_XADD=y
CONFIG_RWSEM_XCHGADD_ALGORITHM=y
# CONFIG_ARCH_HAS_ILOG2_U32 is not set
# CONFIG_ARCH_HAS_ILOG2_U64 is not set
CONFIG_GENERIC_CALIBRATE_DELAY=y
CONFIG_X86_WP_WORKS_OK=y
CONFIG_X86_INVLPG=y
CONFIG_X86_BSWAP=y
CONFIG_X86_POPAD_OK=y
CONFIG_X86_GOOD_APIC=y
CONFIG_X86_INTEL_USERCOPY=y
CONFIG_X86_USE_PPRO_CHECKSUM=y
CONFIG_X86_TSC=y
CONFIG_X86_MINIMUM_CPU_FAMILY=4
CONFIG_HPET_TIMER=y
CONFIG_HPET_EMULATE_RTC=y
CONFIG_NR_CPUS=8
# CONFIG_SCHED_SMT is not set
CONFIG_SCHED_MC=y
# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
CONFIG_PREEMPT=y
CONFIG_PREEMPT_BKL=y
CONFIG_X86_LOCAL_APIC=y
CONFIG_X86_IO_APIC=y
CONFIG_X86_MCE=y
CONFIG_X86_MCE_NONFATAL=y
# CONFIG_X86_MCE_P4THERMAL is not set
CONFIG_VM86=y
# CONFIG_TOSHIBA is not set
# CONFIG_I8K is not set
# CONFIG_X86_REBOOTFIXUPS is not set
# CONFIG_MICROCODE is not set
CONFIG_X86_MSR=y
CONFIG_X86_CPUID=y

при этом BIOS продолжает рапортовать, что у меня 2 CPUs.
P.S.: пробовал так же грузиться с LiveCD Vixta. Пишет конкретно "Ignoring offline CPU"
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Хм... нашлось... но куда "ходило" - не ясно...