Main monitor changes to Secondary when adding a 2nd monitor ??

[BeelzebubUK]

Main monitor changes to Secondary when adding a 2nd monitor on a X1800XT ??

Really not sure why this is happening but its only done it since swapping my X850XT PE for a X1800XT ???

I have dual monitors. main is a 2405FPW and 2nd is a 2005FPW (to the right of the 2405) both using DVI. With just the 2405 plugged in (I ghosted an image of just a barebones XP install with no drivers). It picks up the monitor and everything looks good :

I can plug in the 2005 and it just replicates whats on the 2405FPW and the 2005 is shown as attached to the secondary port on the card so still no problems :

But as soon as I extend the desktop to the 2005 it swaps the 2405 to the secondary port (makes it identify as monitor 2)....moves it to the right of the 2005 (virtually) ansd I then have to drag it to the left of the 2005 and make it the primary to get the desktop working as it should.

Like I said this was working fine before the X1800XT

I've tried swapping the ports round on the card but makes no difference.

Is this just a quirk of the new drivers or a bug
Is there a way to force the 2405 back as the primary and Identify as monitor 1 ?
Does it really make any difference to performance having the main screen as secondary ?

Edit - although the pictures show the 2005 as just plug and play I have tried putting the proper Dell driver on and it makes no difference.


Thanks for any help/advice

 

[BeelzebubUK]

Tried Omega drivers first of all and then went back to Ati drivers but same thing. I'll see if Multimon has any settings to change it. My main worry is that games performance will suffer although I can't say I've noticed anything so far and 3DMark06 got about 4200 on the 1st run.

Just downloading Hydravision from Ati to see if that has anything.

 

[BeelzebubUK]

Nothing in Hydravision or CCC - very weird. Think I'll ghost it again and try some different combinations.

 

[BeelzebubUK]

Well I finally found out what the problem was.

The 2nd monitor (2005FPW) was using a dual-link DVI cable and the main monitor (2405FPW) was using a single-link DVI cable.

I'd already tried changing the 2005FPW to a single-link DVI cable but that made no difference.

I bought a dual-link DVI cable for the 2405 and once I'd rebooted they sorted themselves out and the 2005 has now moved to be the Secondary interface.

Very weird but glad I managed to sort it out.

 

[BeelzebubUK]

There are different pinouts. The single-links have a gap in the middle row whereas the dual-link have all the pins. Haven't found out what difference that actually makes though apart from my particular issue.