I installed an nvidia geforce fx 5500 256 mb video card but only 128 mb is shown when I run dxdiag,why is that?

I installed one 256 mb video card! NOT two 128 mb!|||Try to other programs one is cpu-z at http://www.cpuid.com and speccy at http://www.piriform.com

see what results you"ll get if both reads the same 128 mb then did you download the latest graphic

driver at nvidia .com which is ver.175.19 , if it still reads 128 mb then the graphic card is defective , dxdiag is not that accurate