This section covers ways of finding out about your hardware without opening the box. It's mostly UNIX stuff to be used from the command line. If you want to write programs that determine this stuff, you might find this Rosetta Stone API page useful.

Linux

 $ uname -a
 Linux green.ph.ed.ac.uk 2.6.9-42.0.3.ELsmp #1 SMP Mon Sep 25 17:28:02 EDT 2006 
 i686 i686 i386 GNU/Linux

Memory

On linux, you can find out what memory your machine has like this:

 $ free -m
              total       used       free     shared    buffers     cached
 Mem:           239        235          4          0          0         31
 -/+ buffers/cache:        202         36
 Swap:         2000        216       1783

Or you can use

 $ cat /proc/meminfo       
 MemTotal:       245228 kB
 MemFree:          5264 kB
 Buffers:           408 kB 
 Cached:          40896 kB
 SwapCached:      92316 kB
 Active:         168328 kB
 Inactive:        54412 kB
 HighTotal:           0 kB
 HighFree:            0 kB
 LowTotal:       245228 kB
 LowFree:          5264 kB
 SwapTotal:     2048248 kB
 SwapFree:      1891664 kB
 Dirty:             148 kB
 Writeback:           0 kB
 Mapped:         185496 kB
 Slab:            12484 kB
 CommitLimit:   2170860 kB
 Committed_AS:   416392 kB
 PageTables:       1996 kB
 VmallocTotal:   782328 kB
 VmallocUsed:      2260 kB
 VmallocChunk:   780052 kB

Or even:

 $ dmesg | grep MEM
 0MB HIGHMEM available.
 247MB LOWMEM available.
  MEM window: ea000000-ebffffff

Or, if you can access the machine, watch out for it on boot or check via the BIOS. More info can be found on this Linux and Memory web page, including how to get a machine to recognise memory that is going unnoticed.

What about my CPUs?

You can find out about the CPU's on your machine using this command:

 cat /proc/cpuinfo

Or using this command:

 /usr/sbin/x86info

Be warned that on hyperthreaded systems, one or more real CPUs may be managed as two or more virtual processors. My machine in Edinburgh shows up 4 CPU cores, but actually only has two. I'm not sure how to detect this from the command line.

Solaris

 $ uname -a
 SunOS frontend 5.9 Generic_112233-12 sun4u sparc SUNW,Sun-Fire-15000

Memory

You can find out about your memory, cpu's and peripherals using

 /usr/sbin/prtdiag

Or, if that doesn't work, you could try:

 /usr/platform/`uname -i`/sbin/prtdiag

CPU

This will provide more wordy CPU info:

 /usr/sbin/psrinfo -v

All sorts of kernel info

A remarkably large about of impenetrable information is unleashed my typing:

 kstat

Not sure what much of it means though.

Windows

Much information is available via

 systeminfo

OS X

To look up the available memory, you can use this

 sysctl -n hw.physmem