86GT on 3850 and some of the problems!

Are using colorful 86GT
GPU-Z show

256MB/128BIT
GPU memory clock 540Mhz
I 700/1188

In other words you would like to take a look at this card does not fit? How to enhance performance?
PowerColor HD3850 Polaris

memory 512MB/256BIT
core / memory default frequency 720/1800MHz

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It is said that NV 8 series of fatal flaw?
Sure?

In other words 96GT/9800