On Figures 3 and 4 you can see overclocked GeForce 6600 256 MB (PV-T43P-UDS7) from XFX.

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Figure 3: XFX Overclocked GeForce 6600 256 MB (PV-T43P-UDS7).

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Figure 4: XFX Overclocked GeForce 6600 256 MB (PV-T43P-UDS7), back view.

This video card uses eight GDDR2 256-Mbit 2.5 ns chips from Infineon (HYB18T256161AFL-25)to give it 256 MB of video memory (256 Mbits x 8 = 256 MB). These chips can run up to 800 MHz. Since this video card comes already overclocked at 800 MHz, there is no headroom for overclocking the memory even more inside its specs. Of course you can try overclock it over its specs.

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Figure 5: 2.5 ns GDDR2 memory chips used by XFX Overclocked GeForce 6600 256 MB (PV-T43P-UDS7).