600X, SelectaDock III, GeForce 4 MX4000 almost works

[pkiff]

After more than half a year, I was finally able to work on testing a new video card in my primary computer: a 600X with the memory maxed out and the CPU upgraded to a PIII 850.

Configuration:
600X PIII 850MHz
576 MB RAM
SelectaDock III
nVidia GeForce 4 MX4000 64MB PCI (PNY branded)
nVidia Drivers: version 93.71
DirectX 9.0c
Windows XP SP2

I got tantalizingly close to getting it to work, but I'm getting periodic screen blanking that I can't get rid of. This is much better than system freezing: the screen will go blank and I may or may not get a "signal lost" message from the monitor, but then if I am patient and wait, the monitor will usually turn on again and I can close programs and reboot without requiring a hard power-off.

I used SpeedFan to monitor and log temperatures, since too much heat seemed a likely culprit, but that does not seem to be the case. The system will freeze when the neither the CPU nor the GPU (on the video card) are over 60 degrees Celsius.

When I combine this experience with what I learned from my previous attempts trying to install a GeForce FX5500, I'm starting to believe that the problem is that I don't have enough AC power. I had suspected this before, when I was working with the FX5500, but I thought that the MX4000 would be much less power hungry and so might work okay in a weak power environment, but no such luck.

QUESTION:
So now I wonder if I actually went in and pulled apart the SelectaDock power supply unit (PSU), replaced it with an off-the-shelf, 250 watt component, would the SelectaDock still work...safely? Are motherboards limited to particular wattages generally? Or is there some kind of embedded ACPI controller on the motherboard that will limit the power going to the PCI bus or elsewhere regardless of how powerful the PSU is that I install?

Any information or suggestions on these questions is welcome.

I've already tried to get at the PSU, only to discover that it is encased along with a fan and possibly some other electronics, in a special oblong casing requiring a special (TORX maybe?) screwdriver. And even if I decide to proceed with this work, it may be months before I have the time to work on it. Still, I'd be interested in picking the brain of any of you who know more about regular desktop PSUs and motherboards than I do.

I might even give up on trying to get the GeForce 4 to work before trying a PSU exchange and instead try to install a GeForce 2 card, as they apparently required less power. But I've currently got a Voodoo 5 5500 and it is probably better than a GeForce 2 would be for most things. The only thing is that there are a couple performance issues with my Voodoo 5 that I'm trying to clear up, and that I think a GeForce card will solve.

Here are a couple notes for anyone else trying to install a GeForce 4 in their SelectaDock:

1. I found it more stable to use a PCI ethernet card instead of the PCMCIA Xircom RealPort Combo card. In all other situations, I have found the RealPort cards to be absolute troopers: rock steady and stable in all conditions, but for some reason, I seemed to experience screen blanking more frequently with the RealPort than with an IBM EtherJet 10/100 card.

2. Try forcing AGP 1x. There is a patch that adds a DWORD to the XP registry that will force your GeForce card to operate at AGP 1x instead of 2x or 4x. The 600X is supposed to be 4x capable I think, but I found things more stable after I forced it to work at 1x.

3. I didn't try to install under Windows 98SE since I need my system to work under XP (I usually work with a dual-boot 98SE/XP install). It is possible that someone running exclusively 98SE might be able to get this to stabilize, as I think it is more possible under 98SE to get the nVidia card on a dedicated IRQ, whereas in XP, you are supposed to tell your BIOS to reserve an IRQ for your video card, but on the Thinkpad 600X you can't do that.

4. Additional notes on installing various graphics cards into the SelectaDock III are available from my Unofficial Graphics Card Compatibility List for the SelectaDock III.

Phil.