I just got an old hp pavilion slimline s51010 and am looking for a half height video card that can do low end gaming. I would like it to be under 100$ it just needs to be better than the integrated crap on the Pentium.
what do you mean by half-height? do you mean small form factor?
if so you aren't going to really find anything good for 100 dollars. The BEST you can get is a 750ti and that is in the 130 to 150 dollar range. and you'll be able to do some gaming in 1080p in the medium to high settings with this. (More Mediums than High if you wish to be specific)
http://www.newegg.com/Product/Product.aspx?Item=N82E16814487024&cm_re=GTX_750ti-_-14-487-024-_-Product
http://www.amazon.com/Gigabyte-GV-N75TOC-2GL-Graphics-Cards/dp/B00MW8NXAW/ref=sr_1_17?ie=UTF8&qid=1415418219&sr=8-17&keywords=GTX+750ti
There are no true half height GPU's.
You can get something like this http://www.newegg.com/Product/Product.aspx?Item=1FT-000E-00008
However it has fuck all in gaming performance and the bracket is still full height. you would have to modify the card before you can fit it in a half height case.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814500342
its like $60 i wouldnt spend anymore on your pc its time for a new one.
If you have two slots:
http://store.galaxytechus.com/GALAXY-GeForce-GTX-750-Ti-GC-Slim-2-GB-GDDR5-PCI-Express-30-DVIHDMIVGA-Graphics-CardbrbrBONUS-Low-profile-brackets-now-included-free_p_90.html