This seems to be a bus error. Try to run your cpu and busses at lower speed by underclocking.

Code:
Loading Dump File [C:\Users\Johannes\Downloads\SF_14-11-2012\SF_14-11-2012\111412-42993-01.dmp]
Mini Kernel Dump File: Only registers and stack trace are available


Symbol search path is: SRV*c:\symbols\*http://msdl.microsoft.com/download/symbols
Executable search path is: 
Windows 8 Kernel Version 9200 MP (4 procs) Free x86 compatible
Product: WinNt, suite: TerminalServer SingleUserTS Personal
Built by: 9200.16424.x86fre.win8_gdr.120926-1855
Machine Name:
Kernel base = 0x8160c000 PsLoadedModuleList = 0x817f7e68
Debug session time: Tue Nov 13 20:26:27.035 2012 (UTC + 1:00)
System Uptime: 0 days 0:00:05.767
Loading Kernel Symbols
......................................................
Loading User Symbols
Mini Kernel Dump does not contain unloaded driver list
*******************************************************************************
*                                                                             *
*                        Bugcheck Analysis                                    *
*                                                                             *
*******************************************************************************


Use !analyze -v to get detailed debugging information.


BugCheck 124, {0, 861a3024, 0, 0}


Probably caused by : AuthenticAMD


Followup: MachineOwner
---------


0: kd> !analyze -v
*******************************************************************************
*                                                                             *
*                        Bugcheck Analysis                                    *
*                                                                             *
*******************************************************************************


WHEA_UNCORRECTABLE_ERROR (124)
A fatal hardware error has occurred. Parameter 1 identifies the type of error
source that reported the error. Parameter 2 holds the address of the
WHEA_ERROR_RECORD structure that describes the error conditon.
Arguments:
Arg1: 00000000, Machine Check Exception
Arg2: 861a3024, Address of the WHEA_ERROR_RECORD structure.
Arg3: 00000000, High order 32-bits of the MCi_STATUS value.
Arg4: 00000000, Low order 32-bits of the MCi_STATUS value.


Debugging Details:
------------------




BUGCHECK_STR:  0x124_AuthenticAMD


CUSTOMER_CRASH_COUNT:  1


DEFAULT_BUCKET_ID:  WIN8_DRIVER_FAULT


CURRENT_IRQL:  0


STACK_TEXT:  
82558b24 816d4596 861a3008 817e4578 8180dc60 nt!WheapCreateTriageDumpFromPreviousSession+0x33
82558b40 816d5180 8180dc60 861a3008 817e4578 nt!WheapProcessWorkQueueItem+0x52
82558b5c 816260bd 8180dc60 84967040 00000000 nt!WheapWorkQueueWorkerRoutine+0x1d
82558bb4 8168f8e5 00010000 03131c84 00000000 nt!ExpWorkerThread+0x111
82558bf0 8173c259 81625fb0 00010000 00000000 nt!PspSystemThreadStartup+0x4a
00000000 00000000 00000000 00000000 00000000 nt!KiThreadStartup+0x19




STACK_COMMAND:  kb


FOLLOWUP_NAME:  MachineOwner


MODULE_NAME: AuthenticAMD


IMAGE_NAME:  AuthenticAMD


DEBUG_FLR_IMAGE_TIMESTAMP:  0


FAILURE_BUCKET_ID:  0x124_AuthenticAMD_PROCESSOR_BUS_PRV


BUCKET_ID:  0x124_AuthenticAMD_PROCESSOR_BUS_PRV


Followup: MachineOwner
---------


0: kd> !errrec 861a3024
===============================================================================
Common Platform Error Record @ 861a3024
-------------------------------------------------------------------------------
Record Id     : 01cdc1d4c33cc24b
Severity      : Fatal (1)
Length        : 928
Creator       : Microsoft
Notify Type   : Machine Check Exception
Timestamp     : 11/13/2012 19:26:27 (UTC)
Flags         : 0x00000002 PreviousError


===============================================================================
Section 0     : Processor Generic
-------------------------------------------------------------------------------
Descriptor    @ 861a30a4
Section       @ 861a317c
Offset        : 344
Length        : 192
Flags         : 0x00000001 Primary
Severity      : Fatal


Proc. Type    : x86/x64
Instr. Set    : x86
Error Type    : BUS error
Operation     : Generic
Flags         : 0x00
Level         : 3
CPU Version   : 0x0000000000600f12
Processor ID  : 0x0000000000000000


===============================================================================
Section 1     : x86/x64 Processor Specific
-------------------------------------------------------------------------------
Descriptor    @ 861a30ec
Section       @ 861a323c
Offset        : 536
Length        : 128
Flags         : 0x00000000
Severity      : Fatal


Local APIC Id : 0x0000000000000000
CPU Id        : 12 0f 60 00 00 08 04 00 - 0b 22 98 1e ff fb 8b 17
                00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00
                00 00 00 00 00 00 00 00 - 00 00 00 00 00 00 00 00


Proc. Info 0  @ 861a323c


===============================================================================
Section 2     : x86/x64 MCA
-------------------------------------------------------------------------------
Descriptor    @ 861a3134
Section       @ 861a32bc
Offset        : 664
Length        : 264
Flags         : 0x00000000
Severity      : Fatal


Error         : BUSLG_GENERIC_ERR_*_TIMEOUT_ERR (Proc 0 Bank 4)
  Status      : 0xf600000000070f0f
  Address     : 0x00000000fddf8024
  Misc.       : 0x0000000000000000