Don't go overclocking this LEGO graphics card. It'll melt into a puddle of rainbow goop.
Builder Nick V even made an accompanying specs sheet for it:
>>PowerBuild CRLMRM IRON HD 1640 9IB 64-bit HNSL DVD Extreme x32 HD Ready ABS Support Video Card
Get ready for the latest development in plastic-based video card technology! The PowerBuild IRON HD Video Card features state of the art construction including a Carl Merriam endorsed 7-blade fan to deliver smooth techniques and visual displays whilst running at a constant cool temperature.
>> 1640 Stream Processors
>> 9IB 64-bit ABS Drive
>> Third party enhancements
Oh, and just for the record, in case you would actually want to try and do it: LEGO actually melts at 105 degrees celcius (221 degrees fahrenheit).