Problem using HD5870 and 2 monitors - LAN stops working

[Kuky]

I have a very weird issue that started after I upgraded video card (going from HD4890 to HD5870), I started getting internet stopped working intermitedly... it would be on.. then minute later it stops working... found out my LAN stopps working and I traced it to having second monitor connected to HD5870. The moment I disable 2nd monitor LAN starts working, when I enable second monitor LAN stopps working... what the hell?

 

I haven't had this issue with HD4890 where I had 2 monitos connected to this card... I also have HD4670 and 2 more monitors connected... this issue is there even if I take out HD4670... seems I can only connect 1 monitor to HD5870? :noexpression:

 

I tried connecting main monitor with DVI and second with DVI-VGA adaptor, and also main monitor with HDMI and second monitor with DVI-VGA adapter... still same issue.

 

This is ridicilous... has anyone here come accross anything like this or knows what could be the issue... I am assuming IRQ/s or something are shared and somehow when second monitor is connected it creates conflict with LAN... I am very puzzled :(

 

My hardware:

Windows 7 64bit

motherboard: Asus P5Q-E

RAM: 2x 2GB DDR3

CPU: C2D E8500

Video card 1: HD5870 (connected 27" monitor and 7" touchscreen)

Video card 2: HD4670 (connected 2x 8" monitors)

+ other: trackIR, Cougar HOTAS, Cougar MFDs, Creative X-Fi etc

[Slayer]

Sounds like a driver or BIOS issue. You can try reseting the ESCD in your BIOS and it will force different IRQ's but this shouldn't be an issue with Windows 7 unless you turned off ACPI in your BIOS. Try swapping the cards position in the motherboard and see what happens, maybe your board cant provide enough PCIE lanes? Another possibility is the DVI-VGA adaper is bad or your card just doesnt like it...

 

Issues like this are always hard to nail down.

[Kuky]

Yeah, this is quite stupid to happen... connecting the second monitor actually conflicts not with my PC LAN but Router itself as I noticed today from my work PC it too disconnects when I connect second monitor... I checked for latest firmware for the router and I have the latest one already, same for motherboard BIOS. Looks like I'm stuck with this issue because of new video card till next upgrade...

[Kuky]

Just a heads up for anyone that might possibly come accross rare issue like this... looks like I have solved this issue by installing Catalyst 10.6 driver suite that came on the CD with the video card... I have 2 monitors now connected to HD5870 and 2 monitors connected to HD4670... my internet is no longer dropping out :)

 

EDIT1: bugger... just as I typed this is dropped out again :(

 

EDIT2: I tried disabling wireless and internet came back on... left it like that and it didn'd drop out... I thought I download latest firmware for the router even though it dows I have same version thinking maybe it got corrupted, and after firmware upgrade and again enabling wireless for some 20min now I am not getting dropped... fingers crossed...

 

EDIT3: still no luck with this... I tried changing wireless settings for the router and then just as I thought I fixed this conflict... my gf comes in and says her wireless connection doesn't work... bummer... in the end I decided to not use second monitor of the HD5870 as somehow no matter what I do it conflicts with the Router and connection drops for any PC connected to it. It must be some compatibility issue but how and why connecting second monitor to graphics card causes router to mulfunction is beyond me.

Edited October 23, 2010 by Kuky