I have a rig with 3 GTX780's in it and it has been working very nicely now that it has the new drivers and BOINC version. Now I see here http://www.gpugrid.net/forum_thread.php?id=1150 that up until a certain point the GPUs are listed in terms of GFLOPS peaks, but then after that point they start getting listed in terms of % in performance and performance/Watt using the GTX Titan as a 100% standard. I wonder if this could be updated to a standard system using GFLOPS peaks?

Past that, I see that the Titan Z is a triple slot device while the 3 I have are double slot items. I am pretty sure I could replace the bottom 780 with the Titan Z as far as room goes. Unfortunately I may not be able to do this because the hot swap slots for 2 of the 4 hard drives I have installed will be right up against that bottom device. That would become a heat issue either on the card or on the drives or both.

So my question (other than if the thread about the GPU Card comparisons being standardized) is if I had to remove two of the 780s, would the performance of the project actually see an increase over 3 780s? Does the Titan Z use both GPUs to run the project being seen as 2 GPUs or is it seen as one GPU either doing the units twice as fast or not using one half of the card? I know that the heat issue produced by 3 cards would be reduced because the Titan Z in the top slot and then the remaining 780 in the bottom slot would leave a single slot width in between them while currently they are up against each other with only a small slit between them.

If I can't find a PC to put the other cards in, I am thinking about donating them to the project to the Barcelona office or maybe building a device with a weak CPU that can do the project on the GPUs. Thank you for your feedback on this.
____________
1 Corinthians 9:16 "For though I preach the gospel, I have nothing to glory of: for necessity is laid upon me; yea, woe is unto me, if I preach not the gospel!"
Ephesians 6:18-20, please ;-)
http://tbc-pa.org

Oh, also, since the Titan Zs are a few months old, which is a long time in technological speed these days, is there a better card in the pipeline that I should consider holding off for?

In the context of GPUGRID, the Titan Z's bad value for money. If you really want to upgrade, the GTX9x0s are the best to get - someone will be along in a moment to tell you which offers the best bang/buck.

Thanks for the input. That is exactly what I needed. I think if that other thread laid it out with one standard in the first post people like me just learning would have a better guide to go on. I just don't know what I am looking at. Even a "How To" guide to learning about graphics cards and how they compare and what the different parts of them mean, like shaders and core and memory speeds and all that mean and how they relate to the project would be great for beginners.
____________
1 Corinthians 9:16 "For though I preach the gospel, I have nothing to glory of: for necessity is laid upon me; yea, woe is unto me, if I preach not the gospel!"
Ephesians 6:18-20, please ;-)
http://tbc-pa.org

Dual GPU-ed graphic cards like the GTX 295, GTX 590, GTX 690, GTX Titan Z have the cooler fan between the two GPU chips, in the middle of the card. Therefore the card emits its heat evenly in its both ends, so the half of that heat remains inside the computer's case, which could result in overheating, if the case fans aren't arranged accordingly (there should be fans in the front of the case which blows the hot air out, and fans on the side panel blowing cool air in). So the adequate case fan arrangement is different for dual GPU-ed graphic cards and for single GPU-ed graphic cards. Mixing them in a single host needs a little experimentation to find the right airflow direction for the best cooling.
I'm sure that at some point there will be a dual GPU-ed version of the GTX980, and that will much better bang for the buck than a Titan Z. If there will be a GTX version of Big Maxwell GPU (like the GTX 780 Ti of the Big Kepler GPU), it will be the best buy for GPUGrid.
Dual GPU-ed cards process two workunits at the same time, so a single but faster GPU-ed card is always the better choice.

Thanks Zoltan for answering some of the specifics.

Yes, I don't have the correct fan config for a dual GPU. The fans blow in the front and out the back. There are no fans on the side, which may be my solution to the top of 3 fans getting too hot even now. Currently I have the window open (below freezing outside right now) and a room fan blowing at the front of it, to add the air moving through it around the fans as well as by the fans. It's a good thing I have the CPU water cooled so that it doesn't add too much more to the heat inside the box.

Instead of getting a higher card for just a small amount of extra processing, I decided to put that money directly into the project via a donation of the price of the card. I will probably get a fan installed into the side of that rig and then upgrade to 980s while putting together a new cheaper rig for the 780s.
____________
1 Corinthians 9:16 "For though I preach the gospel, I have nothing to glory of: for necessity is laid upon me; yea, woe is unto me, if I preach not the gospel!"
Ephesians 6:18-20, please ;-)
http://tbc-pa.org