Want to upgrade with right video card

[mgallimore]

Hello. I recently bought a new HP desktop (AMD 64 X2 Dual Core Processor 5000+ 2.60 GHz, 2.942 GB RAM, 400 GB hard drive, current video card is NVIDIA GeForce 6150 SE graphics with TurboCache and up to 128MB dedicated video memory; up to 632MB total available video memory as allocated by Windows Vista), operating system is Windows Vista Home Premium Edition); link for computer is http://www.bestbuy.com/site/olspage.jsp?skuId=8399299&type=product&id=1179877502628 . I bought Medieval II Total War and my game is sluggish and choppy (Samsung 22in LCD widescreen monitor). I was looking on Newegg.com and found a few video cards that are in my price range and hoped for some advice. The cards are:

SAPPHIRE 100196L Radeon X1950PRO 512MB 256-bit GDDR3 PCI Express x16 HDCP Ready CrossFire Supported Video Card - Retail - $152.99

HIS Hightech H195PRF512DDN-R Radeon X1950PRO 512MB 256-bit GDDR3 PCI Express x16 HDCP Ready Video Card - Retail - $179.99

MSI RX2600XT-T2D512EZ Radeon HD 2600XT 512MB 128-bit GDDR3 PCI Express x16 HDMI HDCP Ready CrossFire Supported Silent Heat Pipe Video Card - Retail - $134.99

HIS Hightech H260PRQT512DDN-R Radeon HD 2600PRO 512MB 128-bit GDDR2 PCI Express x16 HDCP Ready CrossFire Supported Video Card - Retail - $139.99

If anyone could help point me in the right direction I would certainly appreciate it (and if I need to post more info, please let me know as well). Thanks to anyone who responds.

[jbennet]

You most likely wont be able to upgrade your video card. HP and Dells have very crappy power supplies (barely enough to run the system they ship with) and these are usually custom in terms of size and wiring meaning an upgrade one wont fit, or will probably fry your PC if it does.

e.g in my dell my PSU is only 305w and a better,standard power supply will not fit in my case , and even if it did, my motherboard has a proprietary pinout.Most modern graphics cards need at least 400w (450-600w is best), meaning im stuck with a crappy x600 hypermemory.