Hey 

I believe the minimum system requirements may need updating. 

I refer to the docs page https://www.mongodb.com/docs/manual/administration/production-notes/

On x86_64 Sandy Bridge is mentioned as the minimum steps, however, when running on an i5-2400 I experienced an illegal instruction error. I'm running MongoDB 8.2.3

Here's the WinDbg analysis from the minidump

```

• • • • • • • • • • • • • Preparing the environment for Debugger Extensions Gallery repositories **************
                             ExtensionRepository : Implicit
                             UseExperimentalFeatureForNugetShare : true
                             AllowNugetExeUpdate : true
                             NonInteractiveNuget : true
                             AllowNugetMSCredentialProviderInstall : true
                             AllowParallelInitializationOfLocalRepositories : true
                             EnableRedirectToChakraJsProvider : false

   -- Configuring repositories
      ----> Repository : LocalInstalled, Enabled: true
      ----> Repository : UserExtensions, Enabled: true

>>>>>>>>>>>>> Preparing the environment for Debugger Extensions Gallery repositories completed, duration 0.016 seconds

• • • • • • • • • • • • • Waiting for Debugger Extensions Gallery to Initialize **************

>>>>>>>>>>>>> Waiting for Debugger Extensions Gallery to Initialize completed, duration 0.765 seconds
   ----> Repository : UserExtensions, Enabled: true, Packages count: 0
   ----> Repository : LocalInstalled, Enabled: true, Packages count: 46

Microsoft (R) Windows Debugger Version 10.0.29482.1003 AMD64
Copyright (c) Microsoft Corporation. All rights reserved.

Loading Dump File [C:\Users\burto\Downloads\mongod.2026-01-30T07-23-47.mdmp]
User Mini Dump File: Only registers, stack and portions of memory are available

• • • • • • • • • • • • • Path validation summary **************
                          Response                         Time (ms)     Location
                          Deferred                                       srv*
                          Symbol search path is: srv*
                          Executable search path is: 
                          Windows 10 Version 19045 MP (4 procs) Free x64
                          Product: WinNt, suite: SingleUserTS
                          Edition build lab: 19041.1.amd64fre.vb_release.191206-1406
                          Debug session time: Fri Jan 30 17:23:48.000 2026 (UTC + 10:00)
                          System Uptime: not available
                          Process Uptime: 0 days 0:00:07.000
                          .....................................
                          Loading unloaded module list
                          .
                          This dump file has an exception of interest stored in it.
                          The stored exception information can be accessed via .ecxr
                          (10b8.1dc8): Illegal instruction - code c000001d (first/second chance not available)
                          For analysis of this file, run !analyze -v
                          ntdll!NtGetContextThread+0x14:
                          00007ffb`41b2f3f4 c3              ret
                          0:006> !analyze -v
                          .....................................
                          Loading unloaded module list
                          .
                          *******************************************************************************
•                                                                             *
•                        Exception Analysis                                   *
•                                                                             *
  *******************************************************************************

KEY_VALUES_STRING: 1

    Key  : Analysis.CPU.mSec
    Value: 453

    Key  : Analysis.Elapsed.mSec
    Value: 4913

    Key  : Analysis.IO.Other.Mb
    Value: 0

    Key  : Analysis.IO.Read.Mb
    Value: 1

    Key  : Analysis.IO.Write.Mb
    Value: 17

    Key  : Analysis.Init.CPU.mSec
    Value: 921

    Key  : Analysis.Init.Elapsed.mSec
    Value: 21142

    Key  : Analysis.Memory.CommitPeak.Mb
    Value: 74

    Key  : Analysis.Version.DbgEng
    Value: 10.0.29482.1003

    Key  : Analysis.Version.Description
    Value: 10.2509.29.03 amd64fre

    Key  : Analysis.Version.Ext
    Value: 1.2509.29.3

    Key  : Failure.Bucket
    Value: ILLEGAL_INSTRUCTION_c000001d_mongod.exe!Unknown

    Key  : Failure.Exception.Code
    Value: 0xc000001d

    Key  : Failure.Exception.IP.Address
    Value: 0x7ff638a1896f

    Key  : Failure.Exception.IP.Module
    Value: mongod

    Key  : Failure.Exception.IP.Offset
    Value: 0x2dc896f

    Key  : Failure.Hash
    Value: {7377d5e4-2a95-1d09-1124-e02048c3789b}

    Key  : Failure.ProblemClass.Primary
    Value: ILLEGAL_INSTRUCTION

    Key  : Faulting.IP.Type
    Value: Paged

    Key  : Timeline.Process.Start.DeltaSec
    Value: 7

    Key  : WER.OS.Branch
    Value: vb_release

    Key  : WER.OS.Version
    Value: 10.0.19041.1

    Key  : WER.Process.Version
    Value: 8.2.3.0

FILE_IN_CAB:  mongod.2026-01-30T07-23-47.mdmp

NTGLOBALFLAG:  0

CONTEXT:  (.ecxr)
rax=0000000000000010 rbx=000001eb58d1704b rcx=00007ff639773280
rdx=0000000000000002 rsi=000001eb6074e040 rdi=000000367ebfa100
rip=00007ff638a1896f rsp=000000367ebfa030 rbp=000000000000003e
 r8=000001eb58d17088  r9=0000000000000000 r10=000001eb58d1704b
r11=000001eb58d1704a r12=000001eb6074e040 r13=0000000000000004
r14=000000000000003e r15=000000367ebfa0d8
iopl=0         nv up ei pl nz na pe nc
cs=0033  ss=002b  ds=002b  es=002b  fs=0053  gs=002b             efl=00010202
mongod+0x2dc896f:
00007ff6`38a1896f c46278f533      bzhi    r14d,dword ptr [rbx],eax ds:000001eb`58d1704b=61000148
Resetting default scope

EXCEPTION_RECORD:  (.exr -1)
ExceptionAddress: 00007ff638a1896f (mongod+0x0000000002dc896f)
   ExceptionCode: c000001d (Illegal instruction)
  ExceptionFlags: 00000000
NumberParameters: 0

PROCESS_NAME:  mongod.exe

ERROR_CODE: (NTSTATUS) 0xc000001d - {EXCEPTION}  Illegal Instruction  An attempt was made to execute an illegal instruction.

EXCEPTION_CODE_STR:  c000001d

STACK_TEXT:  
00000036`7ebfa030 00000000`00000d44     : 00000000`00000000 00000036`7ebfa0f9 00000000`00000000 000001eb`6074e040 : mongod+0x2dc896f
00000036`7ebfa038 00000000`00000000     : 00000036`7ebfa0f9 00000000`00000000 000001eb`6074e040 00000000`00001dbc : 0xd44

STACK_COMMAND: ~6s; .ecxr ; kb

IP_IN_PAGED_CODE: 
mongod+2dc896f
00007ff6`38a1896f c46278f533      bzhi    r14d,dword ptr [rbx],eax

SYMBOL_NAME:  mongod+2dc896f

MODULE_NAME: mongod

IMAGE_NAME:  mongod.exe

FAILURE_BUCKET_ID:  ILLEGAL_INSTRUCTION_c000001d_mongod.exe!Unknown

OS_VERSION:  10.0.19041.1

BUILDLAB_STR:  vb_release

OSPLATFORM_TYPE:  x64

OSNAME:  Windows 10

IMAGE_VERSION:  8.2.3.0

FAILURE_ID_HASH:  {7377d5e4-2a95-1d09-1124-e02048c3789b}

Followup:     MachineOwner
---------

0:006> .ecxr
rax=0000000000000010 rbx=000001eb58d1704b rcx=00007ff639773280
rdx=0000000000000002 rsi=000001eb6074e040 rdi=000000367ebfa100
rip=00007ff638a1896f rsp=000000367ebfa030 rbp=000000000000003e
 r8=000001eb58d17088  r9=0000000000000000 r10=000001eb58d1704b
r11=000001eb58d1704a r12=000001eb6074e040 r13=0000000000000004
r14=000000000000003e r15=000000367ebfa0d8
iopl=0         nv up ei pl nz na pe nc
cs=0033  ss=002b  ds=002b  es=002b  fs=0053  gs=002b             efl=00010202
mongod+0x2dc896f:
00007ff6`38a1896f c46278f533      bzhi    r14d,dword ptr [rbx],eax ds:000001eb`58d1704b=61000148
0:006> r rip
Last set context:
rip=00007ff638a1896f
0:006> u rip-10 rip+20
mongod+0x2dc895f:
00007ff6`38a1895f 83fe3d          cmp     esi,3Dh
00007ff6`38a18962 7216            jb      mongod+0x2dc897a (00007ff6`38a1897a)
00007ff6`38a18964 488d55c4        lea     rdx,[rbp-3Ch]
00007ff6`38a18968 8d04d500000000  lea     eax,[rdx*8]
00007ff6`38a1896f c46278f533      bzhi    r14d,dword ptr [rbx],eax
00007ff6`38a18974 41ffc6          inc     r14d
00007ff6`38a18977 4803da          add     rbx,rdx
00007ff6`38a1897a 488b6f10        mov     rbp,qword ptr [rdi+10h]
00007ff6`38a1897e 482beb          sub     rbp,rbx
00007ff6`38a18981 493bee          cmp     rbp,r14
00007ff6`38a18984 737b            jae     mongod+0x2dc8a01 (00007ff6`38a18a01)
00007ff6`38a18986 66660f1f840000000000 nop word ptr [rax+rax]
0:006> db rip-10 rip+20
00007ff6`38a1895f  83 fe 3d 72 16 48 8d 55-c4 8d 04 d5 00 00 00 00  ..=r.H.U........
00007ff6`38a1896f  c4 62 78 f5 33 41 ff c6-48 03 da 48 8b 6f 10 48  .bx.3A..H..H.o.H
00007ff6`38a1897f  2b eb 49 3b ee 73 7b 66-66 0f 1f 84 00 00 00 00  +.I;.s{ff.......
00007ff6`38a1898f  00                                               .
0:006> lm m mongod
Browse full module list
start             end                 module name
00007ff6`35c50000 00007ff6`3a995000   mongod   T (no symbols)           

```

You can see the instruction here

The bzhi instruction is not available on Sandy Bridge CPUs, and from some research, I believe this instruction wasn't added until Haswell (4th gen).

Interstingly I was able to run MongoDB for some time before this crash occured. Could we update the docs to specify Haswell minimum?