Ok, just got a DreamX "Sample" from Friendtech. First things I tried were Halo and Unreal Championship. I got to places where the games slowed down, tried flipping the switch... and no change. I opened the Xbox up, and to make sure the switch was working (as you switch it, the LED next to the CPU goes dull/bright), so fine.. its all connected and working. Maybe these games just dont "support" a faster CPU. Whilst looking around, I noticed that the unit only has 64MB of RAM!!!! They are meant to come with 128MB as standard, Quality Control?
Further to this, the "Media Key" began to work only if it was held in place. After taking it out of the socket on the rear of the Xbox, I discovered one of the pins had been pushed in, whilst trying to push it back out, I cut through a trace on the PCB, so thats the Media Key (which is basically a cheapmod) ruined. After 10 minutes of cutting the Media Key socket out, I put a Xenium in from this server (hence the downtime, sorry!). It seems to be working fine now.
I encountered a complete lockup whilst installing Gentoox from Stardust and the Xbox's PIC actually has to automatically speed the fan up because the CPU IDLES at a massive 66°C/150°F! With the fan running full time, I can get it down to 56°C/132°F. I tried taking off the heatsink to add some Arctic Silver, but they've used thermal glue, so this is not possible. I'll post benchmarks once I have them. For now, here are some photos (sorry about the low quality!).
Media Key out of heatshrink (Front)
Missing Ram, also notice the heatsink on the MCPX (Cut off at the bottom).