How do I find out what my Motherboard supports, and how many cards I can add? I know I have 2 free PCI slots and I am willing to remove the 56k modem in the 3rd slot because who uses 56k any more? Another question is I am running a Celeron D 2.6ghz socket 478 that I checked and can upgrade to a p4 at 3ghz, who uses a P4 to trade? How many apps can you open and trade with.. Give me details of what you use, how much I can max a Pentium 4? Maybe it is not worth it to upgrade this e-machines, however I am on a budget. Thanks, TradingTimeâ¦.