I currently have a very low end HTPC (bought it from a friend for $25, so I can't complain). It's a dual core AMD Athlon 64 X2 5000+, and I have only 2GB RAM. Benchmarks are significantly worse than the G620. It really struggles with the 3-tuner HDHomeRun Prime, but has no problem at all with the 2-tuner Hauppauge DCR-2650. I use it strictly for streaming to an Xbox media extender. When recording 2-streams and streaming a 3rd program to an extender, my CPU and RAM usage are around 50%, disc activity is around 2%, and network usage is around 5%. Responsiveness is excellent. With the 3-tuner network based tuner, it was pretty much unusable. So, based on my own experience, it looks like your system could easily handle the 2650 but might struggle with the HomeRun.