What Can I Do To Improve Playback Performance of Movies on My Mac Mini

I’ve got a USB hard drive attached to my Airport Extreme which is connected via ethernet to a 1.66 GHz Intel Dual Core Mac Mini with 1 GB of RAM that’s hooked up to my TV. When I watch a movie* in iTunes or QuickTime that I’ve ripped using Handbrake at 2500 kbps, the sound and picture sometimes stutter and skip. I don’t have the problem watching the same film over wifi on my 2.4 GHz Intel Core 2 Duo MacBook with 4 GB of RAM. Nor is there an issue if the film is stored on the Mac Mini’s hard drive, so it seems to me that the ethernet is the bottleneck, however, shouldn’t my wifi connection be an even bigger bottleneck? Short of moving the hard drive and connecting it directly to the Mac Mini (which is not possible for a host of reasons), is there anything I can do to improve the performance when playing back movies?

*For the record, these are movies I own and have ripped mostly so my kids don’t ruin the original disk

I’m still not clear on your setup. Where is the movie stored?

Two things come to mind immediately: add RAM to the Mini, and get rid of the USB drive and use FireWire.

The movie is stored on a hard drive connected via USB to an Airport Extreme. The Mac Mini is connected to the Airport extreme over ethernet.

Are you sure that you have 100base-T cables? It’s possible that your Mini is only connecting at 10Mbps.

How do I check that? The house was wired before I moved in.

Go to “About this Mac” under the Apple menu.
Select “More Info.”
Click on the Network item on the left side.
Highlight the Ethernet connection on the right side of the window.
At the very bottom should be a “Media Subtype” item, and it should say 100baseTX.

Yup, it says 100baseTX.

Well, according to this user report: USB 2.0 HDD/Airport Extreme throughput? - Apple | DSLReports Forums
It’s just slow. Maybe a future firmware upgrade will help.

Not what I wanted to hear, but thanks for the legwork.