Are they compatible?Conditions: GEForce 8800GTX AND 8600GT, 8600GT, or 8600GTS Video Cards (I repeat, "AND"!). PCI Express X16 slots NON SLI Implementation Multiple three to four monitorsExample:PNY VCG8800XXPB-OC GeForce 8800GTX 768MB GDDR3 PCI Express with aPNY VCG8600GXPB GeForce 8600GT 256MB 128-bit GDDR3 PCI Express x16 HDCP Video CardExample:PNY VCG8800XXPB-OC GeForce 8800GTX 768MB GDDR3 PCI Express with aPNY VCG86GTSXPB GeForce 8600GTS 256MB 128-bit GDDR3 PCI Express x16 HDCP Video CardQuestion 1: Will the above combination work or are similar model series cards required (i.e. 8800 plus 8800 only, 8600 plus 8600)?Observation of separate drivers:NVIDIA downloads for Version 158.22 drivers for XP:Individual Version 158.22 drivers for 8800 series cardsIndividual Version 158.22 drivers for 8600/8500 series cardsQuestion 2: Will a single set of drivers work for both 8800 and 8600 or 8500 cards?Thanks:RTH

Yep, same driver supports all of those. If you look on the 158.22 page it says:Product Support List Windows XP 32-bit

But that doesn't make a high/low mix compatible. Allcott

Thanks Allcott: I strongly suspected that but was seeking confirmation. You are the first that I think really recognizes the problem with my speculation/efforts.I am beginning to think that the only sure way to get a reliable combination with a 8800GTX card for multiple monitors is to have dual identical cards in non SLI mode, which I think I am about to try. Expensive, but I am tired of this hassle.I used an old S3 Graphics Inc. Savage 4 PCI card as a secondary for some time successfully, but it will no longer enable in the properties options (MS default drivers) with the 8800GTX installed. I thought the card had gone bad at first, but it works fine by itself with the 8800GTX removed. With both cards installed in the computer, if I uninstall the PCI card (Control Panel>System>Hardware>Device Mgr), the computer just keeps on rebooting after it is found again upon bootup. I then ordered and tried a FX5200 PCI card. By the following installation scenario it also worked for a while, but always booted up with an error message saying that the NVIDIA Driver Service Version 158.22 had encountered a problem and needed to close (drivers for the 8800GTX whatever that means). Yesterday, I got a blue screen of death, and after reinstallation of everything again, I got similar results to the Savage 4. Returned the FX5200 to Newegg.The previous scenario to get a PCI plus the 8800GTX to work was first to remove the 8800GTX. Then to clean house of all graphics drivers. Then to install the PCI card and drivers. Then to remove the PCI card from the computer. Then to reinstall the 8800GTX and drivers. Then to replace the PCI card in the computer. Boot up and everything worked after a fashion for a time at least (borrowed time it would seem).Thanks again:RTH

Might work but the 8800GTX will most likely be slowed down.

Thanks for the reply:I have about decided to go the dual 8800GTX route, Non SLI, Multiple monitors.RTH

That would be my suggestion. You can always SLI them and see, but at the end of the day two cards sharing the same hard drive, motherboard and address spaces are always going to be less than optimised unless they are the same. Did you end up discounting the Matrox TH2Go solution? For the price of two 8800GTX's you could easily have the TH2Go option and just the one card, but it does depend on how you intend configuring the multi-monitor setup.Allcott

I have one 800GTX on my SLI mobo and have used it with my two 19" LCD monitors in FSX monitors and in 16XAA without any noticeable slowdown. This may not always be the case as SX CPU usage improves. Why not start with one card and put another in when and if you think you have a performance bottleneck with the one card. Two 8800s on will require a power supply designed for them as you will need 4 * 12 volt inputs for the back of the two boards.John

RTH...You need the Dual 8800 GTX. They do not play well together in any other formation. I went GTX/GTS at first and had all sorts of issues. Upgraded to dual 1.3/2Gig XFX oC'd cards and have not looked back. See my sig ;)-PaulPrimary RigLiquid CooledIntel C2D E6600 @3.2 gigsAsus P5N32SLI-Plus2 gigs Corsair XMS PC6400 4 4 4 12 @810Dual OC'd XFX 8800GTX @ 2 gigs24 inch Widescreen LCD 16XAA/16XAFDual 19 inch LCD'sRaid-0+1PCPower and Cooling 1k Quad SLIhttp://home.comcast.net/~psolk/3monitorsa.htmlBackup RigAMD 4000 San Diego @ 2.72 Gigs Kingston Corsair XMS CL2XFX 7900 GTX Raid-0

Hello again Allcott, and thanks for the replies.I already have one 8800GTX, so considered the Matrox to be somewhat ill advised. I have ordered a second identical card from Newegg today. (The "VGA PNY VCG8800XXPB-OC 8800GTX R Retail Overclock" version).To me personally, I doubt that I will ever go the SLI route as multiple monitors are a must to me in flightsim. I will implement three 21" CRTs, and one 19" CRT assuming that this will work with the identical 8800GTX cards in the non SLI mode. If you have any advice toward that end, or know that my assumptions are wrong for this arrangement, please so advise.My system specs are attached, and I am editing them to include the new card which should be here by Tuesday. I have tried overclocking, but frankly saw little to no improvement in what is already satisfactory performance. I considered there to be no reason to tax the system so am running with standard settings at the moment.I appreciate the advice and help.Respectfully:RTHASUS P5N-E-SLI MotherboardIntel E6600 Core2 Duo CPUZalman CNPS7700-CU RT CPU Fam4 GB KST DII800 MemoryWinXP ProNVIDIA VCG8800GTX 768MB Primary Video Graphics Card21

Sorry: Duplicate reply. I got an error message on the first attempt and thought it didn't go through.Respectfully:RTH

Hello John.I already have one card. See my system specs on my reply to Allcott.My motivation is to continue to use more than two monitors. Previously I have been able to implement this with PCI cards as the secondaries, but am presently running into conflicts with this arrangement matched with the 8800GTX. This is the reason for all of the dialogue on the second card.I will NOT be useing my matched 8800GTX cards in the SLI mode assuming that my interpretation of the options is correct, and that multiple monitors will be possible with the two cards. Any advice toward that end, or correction of my assumption that this will work is greatly appreciated.Thanks very much for your helpful comments.RTH

Thanks Paul.I suspected as much from the results I have recently been getting.I see that you are running three monitors, but also list "Quad SLI". Am I correct in assuming that you are running in the Non SLI mode on the card arrangement for your multiple monitor implementation? I had the understanding that one was limited to a single monitor in the SLI mode, and that four monitors were possible in the non SLI mode. Anything you could offer to confirm this, or straighten me out would be greatly appreciated. My intentions are to run four monitors if this is possible off of the two matched 8800GTX cards.See my specs on my reply to Allcott.Thanks again for the kind input:RTH

I understand that you need two monitors but I have two monitors attached to my one 8800GTX 768Mb card. As FSX is so CPU bound the one card can take care of business with two monitors no problem. I have two monitors but I normally use only one for FSX as I am a 3dCockpit/Trackir fan. I have however, used two monitors in FSX both with 2 x 7900GTX cards and with my current 8800GTX card with the secondary aircraft panels on the second monitor (and if I ever have to write about how to do this again I'll scream).You are correct with SLI, if you want two monitors forget SLI mode as you have suggested. JohnGood luck with your decision.

HOLY COW, it's PAUL!!!Check your email buddy! (comcast one)