of course you would see a definite gain ,,,
only reason you see 448 is because 64 is allocated to your onboard video memory being used,,
if your computer can handle it ,, semprons are okey cpus,, if you could put an athlon64 3200+ or higher, youd see even more of a boost,, semprons are not really known as a gaming cpu,
i dont know what model you Compaq you have, you didnt say, but i figured you probably have a socket 754 computer, or maybe a 939 ,, both older sockets but still effective, you could probably get an Athlon 64 3500+ for about 40 bucks on ebay.com and 2 gig of ram for about 50 if you shop around for a good deal,, so for about 100 bucks you could have a nice comp for a while till you decide to upgrade, and if lasts you 5 more yrs and youre fine with it,, its only costed you about 20 bucks a yr, or about 1.67 a month,, heck thats less than the cost of 2 small bottles of bottled water,,
might sound like a bit now, and youll get those people who always will tell you up grade to a dual core or something else,, but if youre happy with what youll have , this amount now will pay off in the long run , so youll have the money to spend on a nicer computer, later , and you can get a higher end computer, and will have the money to do so,