Posted 24 November 2011 - 01:17 PM
Well...if you insist on "upgrading" a Compaq system that is 5 years old...you should take note of 2 things, in addition to what DJB already stated:
a. A new motherboard, CPU, RAM and possibly PSU...may cost more and certainly won't be as efficient as a new system, considering the prices of desktops today which are not necessarily "new" but are readily available because they are no longer being pushed to the forefront of the "buy this" campaign that advertisers wage.
b. Compaqs and other OEM systems made by manufacturers like HP, Dell, etc...are not necessarily designed or built with "upgrading" in mind by the manufacturers. Such systems often use PSUs that barely did the job...when the system was new. Installing newer components may increase the power requirements so that a new PSU becomes a key basic consideration.
Sooo...it comes down to how much money you want to invest in a system that is 5 years removed from much of today's computer technology...versus a newer system with (probably) more efficient and more current components.
Something that you should always remember...you will pay more for older parts/components (generally) because they are not likely to be current inventory items...as opposed to more recent components. You can verify this by taking a look at pricing of components at retailers like tigerdirec.com (usually have a fairly extensive inventory of parts) and newegg.com.
IMO, the key thing to consider is how much money you want to spend...and what your reasons/needs are for going to "upgrades" or a new system.
Last tip...never plan to buy components from the system manufacturer, if you do go the upgrade route.