Ok, so I tried overclocking this card, a 8400 GS, using MSI Afterburner and stress testing it wit FurMark.  This is my first time overclocking a graphics card.  The card is on an unknown mobo in a Dell system with a Pent4 2.8Ghz processor.  Here is what surprised me.  First, the original settings were core clock 567Mhz, shader clock 1400Mhz and mem clock 333Mhz.  After continually stepping up the setting, I ended up maxing out the sliders on the Afterburner control panel at core 740Mhz, shader 1820 Mhz and mem 435Mhz.  Everything seems to run fine and temp never got above 83 degrees C during the stress test with FurMark.  The voltage seems to be locked on this card as the voltage slider will not work even after trying to enable voltage adjustment in the settings for Afterburner.  Fan speed seems to be locked also.  Any input would be great.  This just seems odd that I could max out the sliders on the control panel in Afterburner and not have any issues.