I am experiencing really poor local network performance in my home. I was recently using a Linksys WRT54G Router with DD-WRT on it, and a couple comparable Linksys-G PCI cards for connectivity but decided to upgrade hoping it would help with my performance issues.

The computers in my house are connected as follows:

• Comcast Business Class Commercial 25mbps/10mbps (Verified)
• D-Link DGL-4500 Wireless N Router
• Windows 7x64 - D-Link DWA-552 Wireless-N
• Windows 7x64 - D-Link DWA-552 Wireless-N
• Mac Mini 10.6.2 - AirPort Extreme N
• Playstation 3, Hard Wired
• Xbox 360, Hard Wired

Essentially the problem is very specific. Web browsing and uploading/downloading files from the internet is fine, more than fine.

But if I want to say, Stream a video from one of my Windows 7 computers to my PS3, or copy a large video file between either of the PC's or the Mac, I get a consistent 500-900Kbps throughput at the high end.

If I open my network browser, or try to browse my homegroup the response time is horrible.

Both of my Windows computers are showing Strong wireless signals with a connection speed of 300Mbps. I know I can never expect to achieve anything near those speeds, but 500Kbps?

Here is what I have tried so far:

• Enabled Single mode N-only and N/G Only on router
• WPA2 with AES Encrpytion
• Disabled "Remote Differential Compression" in Windows 7
• Disabled TCP "Auto-Tuning"
• Used other software for file copies such as "Teracopy"

I am at the end of my rope. Unfortunately I live in a 75 year old home with plaster walls, so hard-wiring my entire house isn't really an option I can handle right now. Any ideas to help me get decent speed when transferring files across my network would be greatly appreciated.