Low FPS XP Extended desktop w/2x 8800GT...upgrade or fix advice

I have been reading all the forums for a couple weeks trying to decide how to fix the extended desktop issue and dual boxing.
I have 2 8800gt's and winxp.
I run a 26: samsung and a 22" samsung lcd.
I have 4gb of ram
I get low fps as most do when running dual view on xp. Even running ONE instance of wow on the extended (2nd monitor) gives me a 25-27 fps cap!!! when I drag it to the primary side I jump to 60 fps solid! So I'm sure it must be the xp dual view issue.
I have read about the dual view problems in xp and understand they probably are not going away, so I need advice on what my upgrade path should be.

Reading the forums there are 2 thoughts on solution # 1...upgrade to vista ultimate 64.
Some say it will fix my low fps issues and others say it will not. It is supposed to handle DX better on the extended desktop for my dual box alts, but I am looking for confirmation of this.
Since I already have 2 graphics cards, it seems a shame to go back to one since i am getting the same fps with 2 as I did with one in xp. And if this solution works, I will be able to make use of both graphics cards for only the cost of Vista 64.

Solution # 2 is to go 2 machines, which for sure will fix my fps issues and allow me to actually use my 2nd 8800 and not have it sit in a drawer as a loss. I do however, like the ability to scroll across from one screen to the other using one mouse, and one keyboard. I am reading about the vetra, but wouldn't upgrading to vista 64 just solve the extended desktop fps issue anyway? keep both cards in one machine and one mouse one keyboard for a lot less $$ and the same performance than the vetra route.

Solution # 3....unknown
Any suggestions would be greatly appreciated.

Try setting it up as Horizontal span, then use a maximizer like WOWmaximizer or the one within keyclone/another program to put the different WoW instances on different screens.

It's clunky and strange, but it works.

I have since upgraded to vista Ultimate 64.

This may be sort of weird but you did plug your second monitor into the second video card, right? and not in the first video cards second slot? Also, don't forget to turn off SLI.

You'll be better off upgrading to Vista64 to take advantage of your 4gb of RAM. XP always fought with my SLI settings in WoW and caused some green tearing inbetween polygons that got really annoying.

I have tried every combination. I have hooked up the 2nd monitor to both slots of both cards. It doesn't make any difference though, as I get 25fps on the 2nd monitor whether I have one instance of wow running or two... that is making my purchase of the 2nd 8800 gt worthless at this point.
I did the horizontal span, but the only way you can do that is to use one video card only. Once you plug the 2nd monitor into the 2nd graphics card, u lose the horizontal span option. I'm pretty sure using one card and horizontal span will get me up and running, but it will be horrible resolution and I dont mind forking out the money for good res.... Just need to make sure I don't spend anymore money on the wrong solution.

When you upgraded to vista 64 did you change to dual view (which would allow my 2 different resolution monitors to run at native resolution) and get native res and good fps on both monitors?

I have a modest computer, with one 8800gtx and 4G of RAM. I run a 30" at 25x16 and a 20" at 16x12. I run my main toon at 25x16 on the 30", and the 4 clones at 8x6 on the 20". I fps cap all the slaves at 15. I run windows xp and use dual-view, not horizontal span.

Given all this, I get (at 2560x1600 resolution remember) 40-60fps on my main.

The main things I did to make this happen:

• I use one directory for my main toon, and a second directory for all the slaves which is NTFS junctioned off the main directory - search around here for junction, you'll find lots of info. This is key to getting good performance, especially when zoning or loading new textures. I do not recommend using multiple directories. I especially do not recommend running different directories across multiple disks. Yes, I know it sounds like it should help - it doesn't. It made it slower (for me anyway). I blame (praise??) per-disk caching.
• The configuration on the slaves has absolutely every graphical option to its minimum setting. Make sure you don't forgetting to disable anti-aliasing with your video mode selection.
• Keep addons with graphical components to an absolute minimum on clones. I leave my clones at the stock UI, with just a very few mods that I need to help me manage the multiboxing (none of which are graphically intensive).
• BY FAR the biggest help to my frame rate was disabling vsync across all windows. Yes, this does induce tearing, and believe me, you haven't seen tearing until you see it at 30". It took me some time to get over, but I much prefer a smoother frame rate to the lack of tearing. It's a trade-off you'll have to assess yourself.

Those are the steps I took, and I'm pretty happy with the results. I may upgrade at some point because I'd like to lock my main at 60fps, but considering the resolution I'm running, it's not bad at all.