ExtensionTech has posted a review on the Thermaltake G4-VGA heatsink
The memory temperature decrease from the default heatsink to the G4-VGA 'sinks was very relieving, as the TIM appeared to be working well, and the cutting did not seem to lower the cooling value of the sinks. As you can see from the above chart, there were significant temperature drops across the board. This was most likely because the large copper plate that partially made contact with the memory chips on the default heatsink did not dissipate the heat fast enough, causing it to build up.Read more