Reverse memory voltage mod

Certain memory chips such as Qimonda HYB18H512321BF perform sub-optimally at default vMEM voltage of 2.0 V (±3%). Higher overclocks can be achieved by slightly lowering the voltage fed to the chips. Reverse vMEM mod targets the very same Intersil 6549CBZ as the more conventional vMEM mod - but note that the reverse mod uses different legs on the chip (#4 and #13). For the modification use a 50 kΩ variable resistor. Every card and batch of GDDR3 RAM is unique for what comes to it's quirks - and blessings - so there is no universally applicable optimal vMEM voltage. You may be able to find a sweet spot from between 1.80 V and 2.00 V that allows a higher RAM overclock ranging from 50 MHz to even 100 MHz - or nothing at all.