Dual monitor causing performance issues

[Deleted member]

ok so I recently bought a second monitor, and while everything works fine as long as I don't run any games. most games are suffering form major framerate drop.

specs:
2x 1080P monitor
Nvidia GTX295
core i7 950 @4.0GHz
less relevant specs:
6GB RAM
PSU 900W
Win7 ultimate

things is, even if I completely turn off the second monitor in the Nvidia control panel (so the second monitor is only physically connected), the issue remains the same. anyone have a clue what could be up?
(on all tests I had nothing at all running on my second monitor)

I can see my video card not being strong enough anymore, but the issue shouldn't be there if I turn the monitor off. anyoen thoughts?

 

[Zankoku]

What games are you playing, and are you on Win7-64 or 32 bit?

 

[Deleted member]

win7 64 bit.

I managed to solve part of the problem by turning off multi GPU (trial and error, whoo), see below for changes

I tried audiosurf, which used to run at 60+ (fraps refuses to display more) and dropped to 40 (even less on the really busy parts) with the second screen. turning off multi GPU put it back at 59.
second up was portal 1 which used to run at 60+. second monitor didn't immediately change anything until I started shooting portals, which could drop it as far as 21. haven't checked with multi GPU off yet.
third was monday night combat, normally at 50-60, which dropped to an unplayable 5-10 FPS. multi GPU off made it around 24, with drops in heavy combat (aka still mostly unplayable)

in all cases settings were maxed out (I might have turned back AA a bit) and resolution at 1920x1080

 

[Zankoku]

Have you experimented with the second monitor completely disconnected physically as well, to make sure it is definitely the cause of the framedrops?

 

[Dastrn]

could be a driver issue.

 

[Deleted member]

fixed. a short rundown:

installed latest drivers, this did exactly nothing.

proceeded to physcially disconnect second monitor (paying attention to actually disconnect the new one). Game still ran slow, both with multi GPU on and off.

kinda a wtf moment so I decided to just revert both my overclock (950 runs at 3.07 normally) and return nvidia control panel to factory defaults. games ran smooth again.

connected second monitor again, games worked fine.
(tested with audiosurf and MNC)

so either I messed up bad in the Nvidia control panel or somehow my overclock made my videocard slow or something. I'll leave the OC off for now anyway

 

[Zankoku]

Yeah, it's always good to make sure you really know what's causing the problem before you go try to fix it. Glad you're running on full power again.