Answer

Linux

See the /proc/cpuinfo file for detailed information.

AIX

lsdev -C -c processor

[AIX 5.1, AIX 5.2]
         proc0 Available 00-00 Processor

lsattr -El proc0

            [AIX 5.1, AIX 5.2]

lscfg -vp -l proc0

[AIX 5.1, AIX 5.2]
  proc0            P1-C1  Process

Device Specific.(YL)........P1-C1

PLATFORM SPECIFIC

Name:  PowerPC,POWER3
Node:  PowerPC,POWER3@0
Device Type:  cpu
Physical Location: P1-C1     

pmcycles -m #(AIX 5.1+)

(No output available. May not be universal)

bindprocessor –q

[AIX 5.1, AIX 5.2]
The available processors are:  0

HP-UX

ioscan -kfC processor

[HP-UX ia64 11.23]
Class       I  H/W Path  Driver    S/W State H/W Type  Description
===================================================================
processor   0  120       processor CLAIMED   PROCESSOR Processor
processor   1  121       processor CLAIMED   PROCESSOR Processor

[HP-UX 11.23]
Class       I  H/W Path  Driver    S/W State H/W Type  Description
===================================================================
processor   0  32        processor CLAIMED   PROCESSOR Processor

machinfo #(HP-UX 11.23)

[HP-UX ia64 11.23]
CPU info:
   Number of CPUs = 2
   Clock speed = 1600 MHz
   Bus speed   = 400 MT/s
   CPUID registers
      vendor information =       "GenuineIntel"
      processor serial number =  0x0000000000000000
      processor version info =   0x000000001f020204
         architecture revision:       0
         processor family:           31   Intel(R) Itanium 2 Family Processors
         processor model:             2   Intel(R) Itanium 2 processor
         processor revision:          2   Stepping A2
         largest CPUID reg:           4
      processor capabilities =   0x0000000000000001
                      implements long branch:  1
   Bus features
      implemented =  0xbdf0000060000000
      selected    =  0x0000000040000000
         Bus Lock Signal masked

Cache info:
   L1 Instruction: size =   16 KB, associativity = 4
   L1 Data:        size =   16 KB, associativity = 4
   L2 Unified:     size =  256 KB, associativity = 8
   L3 Unified:     size = 3072 KB, associativity = 6

Memory = 4084 MB (3.988281 GB)

Firmware info:
   Firmware revision = 03.17
   FP SWA driver revision: 1.18
   IPMI is supported on this system.
   BMC version: 3.47

Platform info:
   model string =          "ia64 hp server rx2620"
   machine id number =     da23d555-a024-11da-9d9a-5901f5aa9f2b
   machine serial number = US60388358

OS info:
   sysname  = HP-UX
   nodename = hpdev2
   release  = B.11.23
   version  = U (unlimited-user license)
   machine  = ia64
   idnumber = 3659781461
   vmunix _release_version:
@(#) $Revision: vmunix:    B11.23_LR FLAVOR=perf Fri Aug 29 22:35:38 PDT 2003 $

Note: There is a sample UNIX custom inventory script that parses machinfo output, for machine serial number, at: https://kb.altiris.com/article.asp?article=4237&p=1.

getconf CPU_CHIP_TYPE

[HP-UX ia64 11.23]
520225284
[HP-UX 11.23]
619

getconf CPU_VERSION

[HP-UX ia64 11.23]
768
[HP-UX 11.23]
532

getconf HW_CPU_SUPP_BITS

[HP-UX ia64 11.23]
64
[HP-UX 11.23]
64

getconf CLK_TCK

[HP-UX ia64 11.23]
100
[HP-UX 11.23]
100

echo -e "Map\nSelAll\nInformation\nwait\nInfoLog\nDone\nExit\nOK\n" > cstm.tmp && /usr/sbin/cstm -f cstm.tmp

[HP-UX ia64 11.23]
(No output available. May not be universal)  machinfo is recommended instead
[HP-UX 11.23]
(No output available. May not be universal)

cpu speed:
echo speed=`echo itick_per_usec/D | adb -k /stand/vmunix /dev/mem 2>/dev/null | tail -1 | awk '{ print $2 }'`

[HP-UX ia64 11.23]
(No output available. May not be universal)
[HP-UX 11.23]
speed=750

Solaris
 

psrinfo –v

[Solaris 10, x86]
Status of virtual processor 0 as of: 10/30/2007 14:47:03
  on-line since 09/20/2007 13:06:40.
  The i386 processor operates at 3200 MHz,
        and has an i387 compatible floating point processor.
[Solaris 9, sparc]
Status of processor 0 as of: 10/30/2007 14:48:23
  Processor has been on-line since 09/03/2007 20:43:21.
  The sparcv9 processor operates at 296 MHz,
        and has a sparcv9 floating point processor.
Status of processor 1 as of: 10/30/2007 14:48:23
  Processor has been on-line since 09/03/2007 20:43:25.
  The sparcv9 processor operates at 296 MHz,
        and has a sparcv9 floating point processor.

prtconf –pv

[Solaris 10, x86]
             No CPU information
[Solaris 9, sparc]
    Node 0xf006619c
        manufacturer#:  00000017
        implementation#:  00000011
        mask#:  00000020
        sparc-version:  00000009
        ecache-associativity:  00000001
        ecache-line-size:  00000040
        ecache-size:  00200000
        #dtlb-entries:  00000040
        dcache-associativity:  00000001
        dcache-line-size:  00000020
        dcache-size:  00004000
        #itlb-entries:  00000040
        icache-associativity:  00000002
        icache-line-size:  00000020
        icache-size:  00004000
        upa-portid:  00000000
        clock-frequency:  11a48723
        reg:  000001c0.00000000.00000000.00000008
        device_type:  'cpu'
        name:  'SUNW,UltraSPARC-II'      
prtdiag
           [Solaris 10, x86]
                       prtdiag: not implemented on i86pc
           [Solaris 9, sparc]

System Configuration:  Sun Microsystems  sun4u Sun Ultra 2 UPA/SBus (2 X UltraSPARC-II 296MHz)
System clock frequency: 99 MHz
Memory size: 256 Megabytes

========================= CPUs =========================

dmesg | grep "cpu"
            (No output available. May not be universal)