There's really no definite answer as to why ATI why nVidia. Well
if gaming is what the topic starter wants then the question still
falls on what games he wants to play? If he is a serious gamer but
is also budget concious hoping to squeeze every ounce of
performance out of the card within his budget then a wise gamer
like himself/ herself will know to sit back and read reviews. Lots
of trusted sites and forums out there do reviewws with benchmark
tests on specific PC games. If you have read or come across one or
more of them you will realise that reviewers usually pick 2 cards
from either chip technology vendor (i.e ATI/ nVidia) with almost
the equal in price and printed specification for their tests. I
wouldn't say those who supported nVidia are wrong but several
reviews and benchmark/ performance tests recently show that nVidia
is beating on ATI hard. However, wasn't it long before when nVidia
got a bad bashing from ATI with the launch of their 9xxx series
card? We must also note that although all the various cards are
tested in a game but have all the CPU, hard disks, rams and
motherboard manufacturers at that point of time been used for the
tests as well? that will probably take years for one review on a
single game to be completed. the truth is a new card from A chip
maker's been released and at a retail price. Thus B chip maker will
work to release their competing card at a 'competitive' price. and
the cycle goes on. A card costing $1000 may drop to $600 or less in
the space of a few months. so the decision to what to buy still
falls on the buyers themselves. If they are comfortable with a
$1000 nVidia card but finds that another ATI card released soon
after at a lower price and performing better that does not mean
that nVidia is a bad chip maker. Because now in stores that nVidia
card he bought is selling at a lower price than that ATI
card.
Unlike the processor or OS market, the good thing we have with the
graphics card market is there are many license manufacturers to
manufacture the cards based on the 2 graphics chips. So now the
question is who to buy from and why? Well some card manufacturers
were famous for packing in lots of goodies (games, software, cable
accessories etc) with their card so that they can sell them good
but some pull down their prices with the bare minimal so as not to
burden budget buyers with the cost. SOme card makers spent lots
more on advertising their products while some spend on their card
designs. Also the power consumption, thermal management, color,
circuit/ card layout etc determines which group of picky buyers
they attracts. Apparently some flavours ATI while others
nVidia.
As for the budget of $340-$370 (i am assuming it to be in Sing) no
prob. I believe as a PC builder the topic starter can work it out
on his own. Most lower ended PCI-e nVidia 7900 256MB series and ATI
1900 256 MB series (e.g PowerColor) fit the price range. These
cards at 1048x768 resolution can play most games that are not too
GPU intensive. Of course they need to be paired up with a decent
mobo and other hardware too.