Not happy with your cable modem performance? Crack it open and fix it! That’s what forum user Xymox did. After cracking open his DPC3012 he noticed there were a few spots on the main PCB that were not populated with parts. The theory is they saved on budget and didn’t populate all the parts.
Xymox stuffed a huge amount of tantalum capacitors all along the power rail. He also added large capacitor on the power supply. It appears that the modem also runs pretty hot so he addressed the temperature issues by adding Arctic Silver to the heat sink and a fan. After the modifications are all done to the modem, he measured a 1000:1 reduction in power noise.
Having a spare unmodified modem to compare against, Xymox states a gain of 1db to the signal to noise ratio. The upstream power decreased by 1.5db meaning the modem has to try less as hard to maintain a good signal. There is also a side by side plot of ping times captured over a week. The average ping time has improved as well.
Pretty ambitious hack. Read more on the usbjtag forums.