Funny problem (funny hmm, not funny ha ha)

[schmosef]

My primary Win XP development environment is starting to act up. Weird things that shouldn't be happening are happening. Like for instance, Visual Studio doesn't want to debug web sites any more. It keeps telling me I don't have the right security, when I know I do.

Anyway, I decided to setup a dual boot and install a fresh copy of Win XP to migrate my dev tools to.

I've just finished the base install and driver setup. Now my Parhelia is acting funny. I have a Parhelia running dual independant displays and a PCI ATI 9200 card running a third monitor. I'd love to run all three off my Parhelia but sadly I need the flexibility of separate resolutions.

What's wrong is this: My two monitors connected to my Parhelia are kind of flashing. It's very subbtle but completely annoying. It seems to happen whenever there's activity, like dragging a window around the three screens or if the computer is doing something in the background. To describe it better it's kind of like the screens are dimming and coming back very rapidly. It's not a constant thing either it happens in fits and bursts.

Now I thought that this could be a cable problem, like a power cable wrapped around video and causing interference. I checked that and all seems fine. Then I booting back into my old OS and, this is the funny part, the problem isn't there at all!

I'm running the same sets of drivers in both environments, all except for the chipset drivers. I have an Asus A7N8X2.0-DLX mobo and I downloaded the latest drivers from Nvidia for this install. Maybe they are causing the problem? I'm going to try downgrading to the older drivers to see if it helps.

Anybody got any other ideas?

Oh, one more thing. I put SP2 onto the new dev environment. The old environement has all the windows update stuff pre-sp2.

[Umfriend]

It's them Smurfs I tell you!

[Tjalfe]

Servicepack 2 was incompatiple with my compiler ( Xilinx ISE 6.2.03 ) .. try uninstalling it

[schmosef]

SP2 isn't on the install that's having trouble debugging. It's on the new install.

I downgraded my chipset drivers like I said I was going to. It's "better" now. But not perfect. What else could it be?

[schmosef]

Well I just booting back into my old OS to copy some files and it's doing it there too! I guess I spoke too soon about it being something driver or OS related.

I wonder if it's Parhelia or motherboard related? I wonder how to find out? I'm going to have to post this in the Matrox tech support forums when they open again next week.

[schmosef]

Originally posted by Umfriend
It's them Smurfs I tell you!

Yeah, they can be pretty crabby at times!

[schmosef]

Ok, well I've figured out the culprit. Now I need to discover the solution.

Earlier this week I went from an AthlonXP 2800+ to an AthlonXP 3200+. My FSB went from 166MHz to 200MHz.

It seems like the increase in MHz to my FSB is causing the problem. I just didn't notice it right away. To test this I reduced the FSB to 100MHz (my cpu is detecting at 1.1GHz instead of 2.2GHz) and the image is now rock solid.

There must be something in the bios I can set to work around this problem without having to downgrade my FSB speed. I don't even care if it slows down my video a little bit as long as the picture is good and the CPU is able to run at top speed.

Does anyone know a good forum were they discuss motherboard and bios specific issues and such? I know that there's an excellent newsgroup for asus motherboards and I plan to post my question there but I'd like to cover my bases if someone knows of a good site elsewhere.

[Wombat]

So it could be the new CPU, your RAM, your motherboard, or maybe your power supply. Do you get problems if you run at 166MHz? How about increasing the CPU multiplier?

[schmosef]

Well my system is totally stable no matter how my FSB is set. My power supply is an Antec 480P. My RAM is rated for PC3200.

Like I said, the image is rock solid when I set the FSB to 100MHz. At 200MHz there's a lot of quick dimming and restoring. Kind of like an old light bulb that can't maintain it's brightness.

Yes, there are still slight problems at 166MHz.

The CPU multiplier only goes up to 12.5. 12.5x166 gets detected as a 2800+, what I started out with.

[Sasq]

I forget the exact name, but many bios's have an EM Spectrum 'stabilizer', usually its off by default. its either in advanced chipset or bios settings, try flicking it to its opposite setting...

[schmosef]

You mean like spread spectrum?

[Sasq]

thats it. just woke up and my English isn't fully turned on yet

[schmosef]

Ok, well I looked up what it meant and it sounded promising. I took a look in my bios and I actually have separate settings for AGP and FSB spread spectrum. I tried every possible permutation of the two and it's no better.

Any other ideas? Anybody?

[schmosef]

Ok, well after doing some work while my fsb is set to 1% and my agp is set to .5%, I suppose I was too hasty to say that "it's no better." It's definitely better, but not perfect.

I hope someone has other ideas.

BTW, I've posted the issue here. It's a site I found via google. I've got my fingers crossed. Does anybody know any other sites I would be wise to post this at?

[DGhost]

it almost sounds like the old Parhelia banding issue. either that or it is a problem with your motherboards ability to provide stable power to the AGP card...

just a guess...