After update of my Dell OptiPlex 990 MT box running factory to most recent
factory packages, the system stops completely due to a CPU lockup via NMI
watchdog short time after boot. No messages are written to disc, only the
NMI watchdog line were visible on a console.

processor    : 7
vendor_id    : GenuineIntel
cpu family    : 6
model        : 42
model name    : Intel(R) Core(TM) i7-2600 CPU @ 3.40GHz
stepping    : 7
microcode    : 0x29
cpu MHz        : 1612.476
cache size    : 8192 KB
physical id    : 0
siblings    : 8
core id        : 3
cpu cores    : 4
apicid        : 7
initial apicid    : 7
fpu        : yes
fpu_exception    : yes
cpuid level    : 13
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 syscall nx rdtscp lm
constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc
aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx smx est tm2 ssse3
cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave
avx lahf_lm ida arat epb xsaveopt pln pts dtherm tpr_shadow vnmi flexpriority
ept vpid
bogomips    : 6784.24
clflush size    : 64
cache_alignment    : 64
address sizes    : 36 bits physical, 48 bits virtual
power management:

Works when booting the older /boot/vmlinuz-3.16.4-1.g7a8842b-desktop kernel.