Ubuntu – Le processeur I5-4200U ne signale qu’un seul cœur au lieu de 4 [fermé]

sur mon Acer E1-572 je vois sur mon Ubuntu (16.10) un seul cœur de processeur. J’ai un dualboot avec Win10 et dans Win10, les 4 cœurs sont affichés correctement.

Que puis-je faire? J’ai les derniers paquets du microcode, de l’ubuntu-repos installés.

Et quelqu’un peut-il m’aider?

 cat /proc/cpuinfo
processor   : 0
vendor_id   : GenuineIntel
cpu family  : 6
model       : 69
model name  : Intel(R) Core(TM) i5-4200U CPU @ 1.60GHz
stepping    : 1
microcode   : 0x1f
cpu MHz     : 2299.859
cache size  : 3072 KB
physical id : 0
siblings    : 1
core id     : 0
cpu cores   : 1
apicid      : 0
initial apicid  : 0
fpu     : yes
fpu_exception   : yes
cpuid level : 13
wp      : yes
flags       : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm epb tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid xsaveopt dtherm ida arat pln pts
bugs        :
bogomips    : 4589.44
clflush size    : 64
cache_alignment : 64
address sizes   : 39 bits physical, 48 bits virtual
power management:
 

chat / var / log / dmesg | grep CPU

 [    0.000000] smpboot: Allowing 16 CPUs, 12 hotplug CPUs
[    0.000000] setup_percpu: NR_CPUS:256 nr_cpumask_bits:256 nr_cpu_ids:16 nr_node_ids:1
[    0.000000] PERCPU: Embedded 27 pages/cpu @ffff88013f400000 s81408 r8192 d20992 u131072
[    0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=16, Nodes=1
[    0.000000]  RCU restricting CPUs from NR_CPUS=256 to nr_cpu_ids=16.
[    0.000000]  Offload RCU callbacks from all CPUs
[    0.000000]  Offload RCU callbacks from CPUs: 0-15.
[    0.014240] CPU: Physical Processor ID: 0
[    0.014241] CPU: Processor Core ID: 0
[    0.014249] mce: CPU supports 7 MCE banks
[    0.014261] CPU0: Thermal monitoring enabled (TM1)
[    0.106015] smpboot: CPU0: Intel(R) Core(TM) i3-2350M CPU @ 2.30GHz (fam: 06, model: 2a, stepping: 07)
[    0.106075] perf_event_intel: PEBS disabled due to CPU errata, please upgrade microcode
[    0.108002] .... node  #0, CPUs:        #1
[    0.121168] NMI watchdog: enabled on all CPUs, permanently consumes one hw-PMU counter.
[    0.147643] x86: Booted up 1 node, 4 CPUs
[    0.156470] mtrr: your CPUs had inconsistent variable MTRR settings
[    0.156471] mtrr: probably your BIOS does not setup all CPUs.
[    0.809759] microcode: CPU0 sig=0x206a7, pf=0x10, revision=0x23
[    0.809765] microcode: CPU1 sig=0x206a7, pf=0x10, revision=0x23
[    0.809771] microcode: CPU2 sig=0x206a7, pf=0x10, revision=0x23
[    0.809778] microcode: CPU3 sig=0x206a7, pf=0x10, revision=0x23
[    0.890802] ledtrig-cpu: registered to indicate activity on CPUs
 

sudo lscpu

 Architecture:          x86_64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
CPU(s): 1
On-line CPU(s) list: 0
Thread(s) pro Kern: 1
Kern(e) pro Socket: 1
Socket(s): 1
NUMA-Knoten: 1
Anbieterkennung: GenuineIntel
Prozessorfamilie: 6
Modell: 69
Model name: Intel(R) Core(TM) i5-4200U CPU @ 1.60GHz
Stepping: 1
CPU MHz: 2300.000
CPU max MHz: 2600,0000
CPU min MHz: 800,0000
BogoMIPS: 4589.51
Virtualisierung: VT-x
L1d Cache: 32K
L1i Cache: 32K
L2 Cache: 256K
L3 Cache: 3072K
NUMA node0 CPU(s): 0
Flags: fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm epb tpr_shadow vnmi flexpriority ept vpid fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid xsaveopt dtherm ida arat pln pts