Hello all, forgive the somewhat noob question - been working in IT for 25+ years and used to be a huge hardware guy.  Stopped PC gaming about 5-6 years ago but have gotten back into it in a big way, primarily racing simulation.  I built a rather sweet gaming cockpit with an Obutto Ozone cockpit/mount with 3 27" screens, wheel, pedals, shifter, etc. etc.  Link to my setup below if you're curious.  As part of this system I built a rather high end PC, specs are:
 
Asus Hero VII motherboard
Core i7, 4ghz
32GB Ram
2x 256GB SSD (stripped)
EVGA Titan Z 12GB
 
I went with the Z as I wanted to do a single card that could run all 3 monitors at 1080p in ultra settings at 60fps and so far so fantastic.  I've only found one game, the new Dirt Rally that I have to bump a few settings from Ultra to High to get 60fps.  Even then I get 40+ all the time.  Anyway one reason I went with the single card was down the road I could add another and SLI two of them giving me theoretically insane performance (didn't really care about budget BTW).  I'm considering getting a second card as a Christmas gift to myself so I'm looking at eBay and finding a number of Titan X cards fairly cheap (well sub $800).  The question is can I SLI one of those with my Z card or do I have to get another Z card?  Either way am I right to assume that two Titans in SLI mode should be even that much more epic and run everything at 3x1080p ultra settings with ease??
 
Here's a walk-through I did of my simulator a while back so it's a little bit dated as I've added/changed a few components (all around racing, new wheel, shifter, etc)
 

 
Thanks for any help you guys have!!
~L

Scarlet Tech answered your direct question....
 
To answer about getting another Titan Z to SLI with your existing Titan Z.  As I understand it, you are already running your single Z in SLI (Basically 2x780ti (GK110-400) gpus).  Adding another Z would mean you are now Quad-SLI which is typically known to have terrible scaling.  This would also put your total cost for GPUs at $1600?
 
One 980ti with board partner custom cooling solution like the EVGA ACX will usually outperform the Titan Z (780ti SLI) and its only one card.  Two 980ti will only cost you $1300-ish and will CRUSH one or two Titan Z.
 
So... if you can sell your Z and get one or two 980 ti, I think you would be much happier.

LotusExige
  While planning for the future is important I'm not too concerned with 4K yet as I just purchased those 3 Samsung curved 1080p displays.  For gaming they are fantastic, my next upgrade for my displays will be Occulus so I also have made sure I'd be good there and it seems I am.
 
Ok, sorry for that ramble, just wanted to share some background.  So what you're saying is if I replaced my single Titan Z with dual 780ti that would give me better performance than I have now.  If that's the case let me ask the question a different way - what is the most powerful GPU setup, for gaming, that I can get for under $2000. 

Actually 3x1080p is just over 6 million pixels and 4k is jsut over 8 million so the difference between the two is not that huge.
 
I'm assuming you mistyped "replace my Titan Z with dual 780ti". Definitely don't do that!    Replace it with two 980 ti.  Pick a couple from here http://www.evga.com/Products/ProductList.aspx?type=0&family=GeForce+900+Series+Family&chipset=GTX+980+Ti .  Just don't get the Hydrocoppers unless your willing to install a custom water loop for another ~$400 (Rad, Pump, Resevoir, Tubing, etc)
 
Two 980ti is currently the most powerful and is well under $2k USD.  (Well... technically Two Titan X are more "powerful" but only in some titles and configurations and for $600 more = not worth it).  The next release (Pascal) the 1080 or whatever they call it wont happen for another 6 months or so.  But then something more powerful is always around the corner. 

The K|ngp|ns is just a 980ti unless you are going to subzero over clocking. It costs more and has Samsung VRAM, but other than that it doesn't do anything special with air cooling. You would need a phase change, dry ice or liquid nitrogen for benchmarking, and then it will outperform 99% of cards on the market. If you are leaving it on air, just get a 980ti factory overclocked like the 980ti SSC

As an owner of 2 780 classifieds, 4 780ti classifieds and 4 980 Kingpins, you will not benefit enough from the kpe on air or water.

Titan X Hybrid's would give you great performance, exceptional VRAM and cool running cards since you don't want to worry about watercooling. That money would be very well spent compared to a card that costs the same and isn't utilize the way it was built the Titan X reference cooler would be good as well, just not run as cool.

Scarlet-Tech
The K|ngp|ns is just a 980ti unless you are going to subzero over clocking. It costs more and has Samsung VRAM, but other than that it doesn't do anything special with air cooling. You would need a phase change, dry ice or liquid nitrogen for benchmarking, and then it will outperform 99% of cards on the market. If you are leaving it on air, just get a 980ti factory overclocked like the 980ti SSC

As an owner of 2 780 classifieds, 4 780ti classifieds and 4 980 Kingpins, you will not benefit enough from the kpe on air or water.

Titan X Hybrid's would give you great performance, exceptional VRAM and cool running cards since you don't want to worry about watercooling. That money would be very well spent compared to a card that costs the same and isn't utilize the way it was built the Titan X reference cooler would be good as well, just not run as cool.

All valid points.  Water for any videocard is fantastic.  All-in-ones are nice if you have the room in your case for the radiators.

Scarlet-Tech
The kingpins need two 8 pins and a 6 pin each.

Whoops.  I knew that too.
 
Oh hey.  Have you actually seen a Titan X Hybrid in stock anywhere?  Even EVGA always seems to be on Auto-Notify. 

You guys are great - really appreciate all the discussion, really helping me.
 
So from all this and my reading it seems the 980ti Classified are the ones to go with.   One reason I decided that too is all my DisplayPort cables are full size and I don't want adapters or new cables, if you saw my setup it's a removed for language to rewire all that and keep it as perfectly clean as it is.  That said I obviously wouldn't make a dumb decision based on that but it seems the Classified is the best to go with all around for my setup and goals.
 
Question - I do have an Enermax T'i 760 watt PSU now but I remember it only having/coming with 1 cable that went from it to my current Titan Z.  I looked a bit and didn't seem to be able to find the cable or adapter I'd need to run two 980ti Classifieds.  Any idea what I'm missing or will I need to upgrade my PSU as well?  If that's the case I may just stick with my Z for now and wait until next year when the next gen cards are out.  I mean there is only one game I can't play at full 3x1080p Ultra 60fps and that's Dirt Rally.  And I only have to turn a few things down to high to get 60fps so I suppose an upgrade right now is sorta stupid.  I'm just sorta bored and Christmas shopping for myself I suppose!
 
That said if I am stupid what do I need to do on the PSU side?  Seems I'm close here...
 
Again thanks guys, impressed no one has flogged me yet for the noobie questions.  At least my noobie questions are high-end ones!

Oh man, I'm so sorry - clearly by my attitude I hope you didn't take it any way as bad, just me and my potty mouth I suppose.  I will definitely be more careful in the future, I suppose by the fact that you're nicely asking you knew I didn't mean anything negative by it at all.  I really am sorry, feel bad and it won't happen again.
 
Oh and trust me, I've laughed at my fair share of dumb posts.  I'm a moderator on the largest of the Lotus Cars forums and some of the questions we get are just hysterical.  Everyone (99% anyway) mean well so no reason to jump on them, they - like me here - are there to learn and have fun with the toys we love.  I justify my obsession around my racing simulator that it saves me money but not upgrading my actual racecar.  When I hit a wall in the simulator it has a reset button, the racecar not so much...
 
And because I opened my mouth here's a quick shot of my real obsession....
 

Oh man, that is some funny, err, stuff right there!  And yeah, I can feel the face palm moment myself.  His reply "wow, no fans, look how we've progressed" is the icing on the cake!  At least he has the perfect attitude about it and doesn't get upset with anyone, other than himself a bit and at least he can laugh at himself.  Really the worst part for him probably was he couldn't play with his new toy until he gets more new toys.  I hate when that happens, you don't get some adapter, etc. and have to wait because you didn't do enough research.  There's a reason companies sell fully built systems, right?
 
As for the Exige it's a fantastic piece of machinery and I too never thought I'd own one.  Life has been rather nice to me lately and really, in some ways they aren't that expensive.  You can get a base model Elise for around $35k in great condition, the main issue for most is you have to own another car as these things aren't "cars" in the normal sense.  Think motorcycle with room for someone else to sit.  Mine is a full racecar at this point so no more street driving where it's honestly horrible.  Loud, low, horrible visibility, no one can see me, worthless stereo, AC is an asthmatic blowing at you through a straw, etc.  Only good things as a car - no fat chicks and if she's wearing a mini-skirt she's taking it off to get in.  That went well for me, once...  Anyway mines a highly modded racecar at this point, fully built race motor making 365 at the wheels at 1800lbs.  So yeah, it's a better power-weight than a Bugatti Veyron SuperSport.  Yeah, it's nuts.  Okay, I suppose I've gotta further, err, discuss (not bragging, right??)  Here's one of my better videos from it, a few seconds off my fastest lap but the best mutli-camera video I've done:
 


She's definitely fun and a handful, about the adrenaline pump I've ever been in.  If you're even in Colorado drop me a line and I'll give ya a ride!

Ah, that makes sense - thanks for explaining.  We deal with the same, err, stuff on LotusTalk where I moderate.  We don't allow links or PMs until 10 posts, that usually save us.  If you'd like (willing) grab that link and toss it in your post so others can see.  While this thread has been helpful and a riot I doubt I'll ever get anywhere near 50 posts as this might be the only topic I ever create/follow here.  Great site, just not something I usually need.
 
You don't happen to do any online racing do you?  Love to connect there if so...

LotusExige
Ah, that makes sense - thanks for explaining.  We deal with the same, err, stuff on LotusTalk where I moderate.  We don't allow links or PMs until 10 posts, that usually save us.  If you'd like (willing) grab that link and toss it in your post so others can see.  While this thread has been helpful and a riot I doubt I'll ever get anywhere near 50 posts as this might be the only topic I ever create/follow here.  Great site, just not something I usually need.
 
You don't happen to do any online racing do you?  Love to connect there if so...

It is a video in your original post now. Is that a little better?

Also, [tube ] insert the share link from YouTube which is usually *http://youtu.be/somethinghere*[/tube] will be the way to insert videos directly instead of linking them out.

[tube]http://youtu.be/l9neCzTQozY[/ tube] (no spaces in the brackets of course)

Yes, only after 50 posts as it is still a link inside the tube tag.

Hmm, so what you're saying is the PSU is sorta like the engine in my car.  I wouldn't want to run it at redline 90% of the time and if I did I'd probably have to replace/rebuild it about once every 60-100 hours of run time.  Oh wait, that is what I do with my car!  So yeah, I hear ya, sounds like when I do the new cards it'll be time for new PSU as well.
 
Thanks for all your help guys - and funny that you didn't suggest the Hydrocopper as you thought I might be that - err, uh, well, uneducated.  Really I'm not that bad, I promise.  I'm, uh, far far worse.....   :-)