quick ram question

  Looking at buying a used older stick of ram to get some more use out of this computer. I have 256mb of ram, pc2100 ddr 266 made under the name NANYA, i believe.
  Ive been looking around on ebay and the prices are good but is it okay to mix sizes and brand names at all?

  I have a link below but i cannot tell what size it is so anyone want to identify it for me?

http://cgi.ebay.com/1024-Mb-184-PIN-DDR-DIMM-PC-2100-266Mhz-PC2100-1GB-REG_W0QQitemZ170049578193QQihZ007QQcategoryZ74942QQssPageNameZWDVWQQrdZ1QQcmdZViewItem?hash=item170049578193

Perfectly okay to mix brands, but in some (rarely now) cases, mixing sizes will cause problems.  Check your manual or go to the mobo manufacturer's site to be sure.  If your mobo can't handle 1G in the slot, it could cause problems too.  But without knowing, I'd say go for it.  Also, if you put a faster type of DDR SDRAM in (PC2700 or PC3200), it'll painlessly downclock it to match whatever your motherboard can handle (or if you're using RAM that's slower, it'll use that speed).  Sometimes newer RAM is cheaper, so keep that in mind (also useful for future upgrades). :)

Also, 3 is a fucking retard.
1) More RAM = less hard disk use = more battery life.
2) 2.133GB/s (maximum theoretical throughput of PC2100) >>>>> ~45MB/s (average maximum throughput of a 5400rpm hard disk)