[WOW] <2 FPS when using multiple monitor

Since MoP I encounter huge LAG spike where FPS drop below 1-2 for a least 1 toon (Not always the same one). This issue is weird to me, since I have kept the same computer as before, same GPU and monitor configuration, and everything was fine up to the expansion.

I had guessed that a add-on/patch/driver/innerspace/wow may have been in trouble, so everything has been re-installed (Some item several times). Tried to run clean install with no Add-on at all, minimum screen quality, no change.

I am using the insta-switch option in the Window layouts, which seems to be the most probable cause of the issue. If Ichange to non-insta switch of region (and do not use synchronize game resolution) the lag is not present.

This seems strange because:
1) this happen only in the outside world. When playing a dungeon the issue is not encountered (no matter the amount of details/screen quality)
2) just before the expansion, no problem whatsoever where encountered.

Computer is a DELL studio XPS 435T (4 CPU, each hyperthreaded, at 2.7 GHz) with 12 GB ram
Display adapter is L ATI Radeon HD 4800 (which support 2 monitor natively)
HDD are setup in RAID-0

Configuration is below.
http://www.privatepaste.com/78a292e549
Note, using mainly the Character set 5-Man A-Team for this test.
Window Layouts 5-Man is the one with the lag issue
Both 5-Man Slow Swap and 5-Man no Swap do not have the issue.

(But it is bothersome not being able to qwick swap anymore in an instance/BG)...

In all situation, CPU, Memory, GPU are not fully utilized.
test where also performed without any other running external software, like Antivirus or other resource hog.

[lax]

You didn't mention what version of Windows you're using, but if you're using Windows XP specifically, then I'm going to say it's expected behavior and documented under GPU Management. The issue I'm referring to no longer exists with Vista or later (7, 8, etc), so if you are not on XP then it's not the issue I have in mind.

If you are on a newer Windows than XP, then it might be relevant to suggest switching between DirectX 11 and DirectX 9 modes. Some users have experienced new problems with DX11 since MoP that they did not have before, and switching to DX9 was an improvement.

I am sorry for not including all the details in my previous post (And btw, your are crazy fast with your answer!)

I am running on Windows Vista 64bits (I know... not perfect)

I already downgraded to DirectX 9. You are right in reporting that Dx11 is not so good, I saw some speed increase by going Dx9, but that did not translate to a solution when I get the Near freeze I am describing.
I fact, I read nearly every post reporting lag or speed issue, and tried most proposed solution, but did not found a situation quite close to what I am seeing, hence my post here.

I also tried to change the V-Sync (Tried to ON and OFF)
Updated Graphics card driver
Turned off and on all features of my graphic board, both in WOW, and outside, in the graphic card control panel.

I also monitored my IP connection to ensure that there is not a running service using my bandwidth without me knowing... no.

I am kinda lost on what to look at right now

I had this issue on a Shaman team of mine with Jamba installed, then went thru each addon section of Jamba and found that the Use Bar was causing a large spike on one toon only since I had Bloodlust in it. I'm not sure what could it be on your end, however sometimes cleaning out the WTF config files and making fresh ones help out once in a while. I been doing that every other week or so to keep everything running nicely around 30/60 on each team's window.

Usually this would be a great idea (And also one I tried)
But since it did not worked, I went one step further and did a simple clean install, without ANY add-on, to rule out that as a possible cause for the issue.

Hello everyone, let me add these information on how it was resolved, so that if anyone else get that issue, at least some background information can be used...

Looking at it now, it was quite simple.

After my last post, I lost the main component of my computer. i.e.: The smoke that was up to that moment self-contained within my graphic cards!

(I know, this is not really the way it work, but I feel it more poetic that way)

Nonetheless, replaced the card be a brand new GFX 660 Ti, and the problem is now solved.

Now I'm looking at my computer log of the past 2 month or so (Since MoP went out) and I actually got a power issue, caused by that faulty card. Just happened that both event (MoP coming out, and my graphic card starting to behave strangely) were simultaneous, (but I mostly think unrelated).

Regards