新人求助：Ubuntu14.04LTS，频繁死机

[solitudeycq]

近期由于学习需要安装了Ubuntu，14.04 LTS，但是每次进去之后用不到半个小时就死机，并且切不到命令行，随后黑屏有如下信息：
mce:[Hardware Error]:CPU 0:Machine Check Exception: 0 Bank 4:be00000000800400
mce:[Hardware Error]:TSC 0ADDR 7f5d5a7f0f00 MISC 7f5d5a7f0f06
mce:[Hardware Error]:PROCESSOR 0:40671 TIME 1448891234 SOCKET 0 APIC 0 microcode d
mce:[Hardware Error]:Run the above through 'mcelog --ascii'
mce:[Hardware Error]:CPU 1:Machine Check Exception: 0 Bank 3:be00000000800400
mce:[Hardware Error]:TSC 0 ADDR 7f5d5a7f0f00 MISC 7f5d5a7f0f06
mce:[Hardware Error]:PROCESSOR 0:40671 TIME 1448891234 SOCKET 0 APIC 0 microcode d
mce:[Hardware Error]:Run the above through 'mcelog --ascii'
mce:[Hardware Error]:CPU 7:Machine Check Exception: 5 Bank 4:be00000000800400
mce:[Hardware Error]:RIP !INEXACT! 10:<ffffffffff8103fafe> {mwait_idle_with_hints+0x5e/0x70}
mce:[Hardware Error]:TSC 3ee1640feb5 ADDR 7f5d5a7f0f00 MISC 7f5d5a7f0f06
mce:[Hardware Error]:PROCESSOR 0:40671 TIME 1448863996 SOCKET 0 APIC 0 microcode d
mce:[Hardware Error]:Run the above through 'mcelog --ascii'
mce:[Hardware Error]:Some CPUs didn't answer in synchronization
mce:[Hardware Error]:Machine check: Invalid
Kernel panic - not syncing: Fatal machine check on current CPU
Shutting down cpus with NMI
drm_kms_helper:panic occurred,switching back to text console
Rebooting in 30 seconds...


我闹不明白是什么问题，我的电脑双显卡，已经安装了英伟达闭源驱动，是通过应用程序“附加驱动”安装的，CPU是i7-5700，各位坛友帮忙分析一下，跪谢！

[poloshiao]

開機選單
Memory test (memtest86+)
讓它跑個 幾個鐘頭 看看 PASS 幾回 都順利