The SMBIOS expose the info about the installed processors in the table type 4. Check the next snippet that shows how obtain such data using the TSMBIOS (remember, if you are using FPC, you can use this library in Windows and Linux).

{$IFDEF FPC}{$mode objfpc}{$H+}
{$ELSE}
{$APPTYPE CONSOLE}
{$ENDIF}

uses
  Classes,
  TypInfo,
  SysUtils,
  uSMBIOS;

function SetToString(Info: PTypeInfo; const Value): String;
var
  LTypeInfo  : PTypeInfo;
  LIntegerSet: TIntegerSet;
  I: Integer;

begin
  Result := '';

    Integer(LIntegerSet) := 0;
    case GetTypeData(Info)^.OrdType of
      otSByte, otUByte: Integer(LIntegerSet)  := Byte(Value);
      otSWord, otUWord: Integer(LIntegerSet)  := Word(Value);
      otSLong, otULong: Integer(LIntegerSet)  := Integer(Value);
    end;

  LTypeInfo  := GetTypeData(Info)^.CompType{$IFNDEF FPC}^{$ENDIF};
  for I := 0 to SizeOf(Integer) * 8 - 1 do
    if I in LIntegerSet then
    begin
      if Result <> '' then Result := Result + ',';
      Result := Result + GetEnumName(LTypeInfo, I);
    end;
end;


procedure GetProcessorInfo;
Var
  SMBios             : TSMBios;
  LProcessorInfo     : TProcessorInformation;
  LSRAMTypes         : TCacheSRAMTypes;
begin
  SMBios:=TSMBios.Create;
  try
      WriteLn('Processor Information');
      if SMBios.HasProcessorInfo then
      for LProcessorInfo in SMBios.ProcessorInfo do
      begin
        WriteLn('Manufacturer       '+LProcessorInfo.ProcessorManufacturerStr);
        WriteLn('Socket Designation '+LProcessorInfo.SocketDesignationStr);
        WriteLn('Type               '+LProcessorInfo.ProcessorTypeStr);
        WriteLn('Familiy            '+LProcessorInfo.ProcessorFamilyStr);
        WriteLn('Version            '+LProcessorInfo.ProcessorVersionStr);
        WriteLn(Format('Processor ID       %x',[LProcessorInfo.RAWProcessorInformation^.ProcessorID]));
        WriteLn(Format('Voltaje            %n',[LProcessorInfo.GetProcessorVoltaje]));
        WriteLn(Format('External Clock     %d  Mhz',[LProcessorInfo.RAWProcessorInformation^.ExternalClock]));
        WriteLn(Format('Maximum processor speed %d  Mhz',[LProcessorInfo.RAWProcessorInformation^.MaxSpeed]));
        WriteLn(Format('Current processor speed %d  Mhz',[LProcessorInfo.RAWProcessorInformation^.CurrentSpeed]));
        WriteLn('Processor Upgrade   '+LProcessorInfo.ProcessorUpgradeStr);
        WriteLn(Format('External Clock     %d  Mhz',[LProcessorInfo.RAWProcessorInformation^.ExternalClock]));

        if SMBios.SmbiosVersion>='2.3' then
        begin
          WriteLn('Serial Number      '+LProcessorInfo.SerialNumberStr);
          WriteLn('Asset Tag          '+LProcessorInfo.AssetTagStr);
          WriteLn('Part Number        '+LProcessorInfo.PartNumberStr);
          if SMBios.SmbiosVersion>='2.5' then
          begin
            WriteLn(Format('Core Count         %d',[LProcessorInfo.RAWProcessorInformation^.CoreCount]));
            WriteLn(Format('Cores Enabled      %d',[LProcessorInfo.RAWProcessorInformation^.CoreEnabled]));
            WriteLn(Format('Threads Count      %d',[LProcessorInfo.RAWProcessorInformation^.ThreadCount]));
            WriteLn(Format('Processor Characteristics %.4x',[LProcessorInfo.RAWProcessorInformation^.ProcessorCharacteristics]));
          end;
        end;
        Writeln;

        if (LProcessorInfo.RAWProcessorInformation^.L1CacheHandle>0) and (LProcessorInfo.L2Chache<>nil)  then
        begin
          WriteLn('L1 Cache Handle Info');
          WriteLn('--------------------');
          WriteLn('  Socket Designation    '+LProcessorInfo.L1Chache.SocketDesignationStr);
          WriteLn(Format('  Cache Configuration   %.4x',[LProcessorInfo.L1Chache.RAWCacheInformation^.CacheConfiguration]));
          WriteLn(Format('  Maximum Cache Size    %d Kb',[LProcessorInfo.L1Chache.GetMaximumCacheSize]));
          WriteLn(Format('  Installed Cache Size  %d Kb',[LProcessorInfo.L1Chache.GetInstalledCacheSize]));
          LSRAMTypes:=LProcessorInfo.L1Chache.GetSupportedSRAMType;
          WriteLn(Format('  Supported SRAM Type   [%s]',[SetToString(TypeInfo(TCacheSRAMTypes), LSRAMTypes)]));
          LSRAMTypes:=LProcessorInfo.L1Chache.GetCurrentSRAMType;
          WriteLn(Format('  Current SRAM Type     [%s]',[SetToString(TypeInfo(TCacheSRAMTypes), LSRAMTypes)]));

          WriteLn(Format('  Error Correction Type %s',[ErrorCorrectionTypeStr[LProcessorInfo.L1Chache.GetErrorCorrectionType]]));
          WriteLn(Format('  System Cache Type     %s',[SystemCacheTypeStr[LProcessorInfo.L1Chache.GetSystemCacheType]]));
          WriteLn(Format('  Associativity         %s',[LProcessorInfo.L1Chache.AssociativityStr]));
        end;

        if (LProcessorInfo.RAWProcessorInformation^.L2CacheHandle>0)  and (LProcessorInfo.L2Chache<>nil)  then
        begin
          WriteLn('L2 Cache Handle Info');
          WriteLn('--------------------');
          WriteLn('  Socket Designation    '+LProcessorInfo.L2Chache.SocketDesignationStr);
          WriteLn(Format('  Cache Configuration   %.4x',[LProcessorInfo.L2Chache.RAWCacheInformation^.CacheConfiguration]));
          WriteLn(Format('  Maximum Cache Size    %d Kb',[LProcessorInfo.L2Chache.GetMaximumCacheSize]));
          WriteLn(Format('  Installed Cache Size  %d Kb',[LProcessorInfo.L2Chache.GetInstalledCacheSize]));
          LSRAMTypes:=LProcessorInfo.L2Chache.GetSupportedSRAMType;
          WriteLn(Format('  Supported SRAM Type   [%s]',[SetToString(TypeInfo(TCacheSRAMTypes), LSRAMTypes)]));
          LSRAMTypes:=LProcessorInfo.L2Chache.GetCurrentSRAMType;
          WriteLn(Format('  Current SRAM Type     [%s]',[SetToString(TypeInfo(TCacheSRAMTypes), LSRAMTypes)]));

          WriteLn(Format('  Error Correction Type %s',[ErrorCorrectionTypeStr[LProcessorInfo.L2Chache.GetErrorCorrectionType]]));
          WriteLn(Format('  System Cache Type     %s',[SystemCacheTypeStr[LProcessorInfo.L2Chache.GetSystemCacheType]]));
          WriteLn(Format('  Associativity         %s',[LProcessorInfo.L2Chache.AssociativityStr]));
        end;

        if (LProcessorInfo.RAWProcessorInformation^.L3CacheHandle>0) and (LProcessorInfo.L3Chache<>nil) then
        begin
          WriteLn('L3 Cache Handle Info');
          WriteLn('--------------------');
          WriteLn('  Socket Designation    '+LProcessorInfo.L3Chache.SocketDesignationStr);
          WriteLn(Format('  Cache Configuration   %.4x',[LProcessorInfo.L3Chache.RAWCacheInformation^.CacheConfiguration]));
          WriteLn(Format('  Maximum Cache Size    %d Kb',[LProcessorInfo.L3Chache.GetMaximumCacheSize]));
          WriteLn(Format('  Installed Cache Size  %d Kb',[LProcessorInfo.L3Chache.GetInstalledCacheSize]));
          LSRAMTypes:=LProcessorInfo.L3Chache.GetSupportedSRAMType;
          WriteLn(Format('  Supported SRAM Type   [%s]',[SetToString(TypeInfo(TCacheSRAMTypes), LSRAMTypes)]));
          LSRAMTypes:=LProcessorInfo.L3Chache.GetCurrentSRAMType;
          WriteLn(Format('  Current SRAM Type     [%s]',[SetToString(TypeInfo(TCacheSRAMTypes), LSRAMTypes)]));

          WriteLn(Format('  Error Correction Type %s',[ErrorCorrectionTypeStr[LProcessorInfo.L3Chache.GetErrorCorrectionType]]));
          WriteLn(Format('  System Cache Type     %s',[SystemCacheTypeStr[LProcessorInfo.L3Chache.GetSystemCacheType]]));
          WriteLn(Format('  Associativity         %s',[LProcessorInfo.L3Chache.AssociativityStr]));
        end;

        Readln;
      end
      else
      Writeln('No Processor Info was found');
  finally
   SMBios.Free;
  end;
end;