Although this Titan X has been working pretty well testing/benching, It's Not enough for me to want to spend the extra cash on three more ATM (even if I could find more available) not to mention the loss I'm bound to incur when I get ready to sell just this one! LOL!
 
Think I'll wait and see what else is offered up later on before I decide whether I'll be going back to a 4-Way SLI setup again.

From the GPU Phase Change tests I did using my EVGA GTX 480 in a few posts back, I found that even though the initial temps on the GPU at idle on the desktop was -14C, Upon starting the Graphics tests on Fire Strike the Temps would immediately climb to around +22C and would not hold sub-zero temps any better than Chilled water cooling, probably due to the higher heat output (250W plus) that the GPU put out compared to the lower heat output (140W plus) of the CPU under Phase Change.
 
Alas, As I expected, It becomes all too obvious why DICE/LN2 Cooling is the only way to "Maintain" very low temp sub-zero cooling under High Load Bench Testing including all the preparation needed to the components, But even then if you do use this type of cooling, you will STILL also have to do the "Major Hardware Mods" if you wish to come close to what the Highest GPU OC's are reaching.
 
I have been losing enough $$$$ as it is every time I sell components to update my Rigs, But at Least I am not Voiding my Warranties by physically altering the Graphics Cards to the point where I can't Sell them, So it's still CPU=Phase Change and GPU=Chilled Water for my builds if I want to get SOME monetary returns on my investments. 
 
 
 
 

As you may have seen in previous posts over the years, I have built a few LARGE Cascade Phase Change Units (for CPU's only) that did manage to get below -100C, But under Heavy Overclocked Loads still had a hard time maintaining half of that temp, and that was years ago with Intel Single-Core Socket 478 Processors!
 
It just comes down to looking at the practical end of building such an enormous Cooling Device and asking yourself "Can I operate this Cooling System 24/7 and is This Really going to be Worth all the expense/trouble?"
 
Back in the days, I've seen a few Multiple-Cascade Phase Change Units reach around -150C, But they could never maintain temps of -150C to -170C (like LN2 does by just keep adding more under heavy benching loads to maintain the desired temp), Not to mention the expense/size and power requirements it takes to do so.
 
  
 

awalleyeguy
 But a 480 must put out a lot more heat than a Titan X?

 
True, From what I've seen a GTX 480 uses around 450W compared to a Titan X which is supposedly rated at 250W, But my ASETEK Vapochill Phase Change I used in my tests is only rated for a 180W Load and can't maintain sub-zero temps over that rating.
 
I will agree that the Vapochill would fair better with the lower heat rating of a Titan X and that would result in some additional Overclocking overhead, But it still would require a higher heat load Phase Change to maintain temps.
By contrast, Even my Custom 300W load rated Phase Change only adequately Cools my 140W rated 5960X CPU running at 4.8GHz and temps DO rise to the upper +20C during Firestrike CPU Tests when the CPU is under Full Load.
 
So Yes, It would allow higher Overclocks on a Titan X, But still could not reach/maintain the Extreme sub-zero temps of LN2 or even DICE for that matter that if you so desired would be required to reach and HOLD the 2000+ MHz that has been achieved by K|ngp|n and a few others.
 
Since I've always wanted my Systems to be able to not only run Benches, But also Games, Web surfing, etc...24/7 without the constant "maintenance" of watching/adding/adjusting sub-zero cooling liquid temps/levels, I have been using only Phase Change and Chilled Water Cooling Solutions on my Rigs that I can leave almost unattended.
 
 

Got a higher score (#20 in Fire Strike HOF) by enabling K-Boost in Precision X, But Notice that the GPU Temp before the bench is now only -11C due to using a higher GPU voltage of 1.230v at 1514MHz GPU/ 2005MHz Memory which is starting to reduce the effective cooling under bench loads while running Fire Strike graphic tests.
 
Possibly could to change to a modded Vbios for a higher Power Target/additional voltage and will continue testing with the stock Vbios for further improvements.
 
As I have stated before and these results show, If you want to keep up in the Top 10 in Benching whether using one Card or Four in SLI, You'll need LN2 Cooling to accomplish those Ultra High GPU and/or CPU Overclocks.
 
 

Flashed to a Titan X SC 425W Modded Vbios from Overclock.net which raised the Power Target to +121% and a starting GPU clock of 1127MHz, But ran into the same temp problem at anything over 1500MHz on the GPU where the Phase Change couldn't maintain cold enough temps during Fire Strike Graphics Tests, So Flashed back to the stock Titan X Vbios which seems to be the only one that allowed a 1514MHz GPU / 2005MHz Memory OC.
 
Only other Cooling solution I might persuade myself into trying is DICE on the CPU to get higher than 4.8GHz on the 5960X, But as you remember when I attempted that with my ASUS Rampage IV / 4930K at a temp of -62.5C, It resulted in both a CPU and Motherboard Failure that although I managed to get covered under warranty by Intel AND ASUS, Kind of left me with some Doubts about attempting that method any time soon again.
 
Still can't figure out exactly what caused those failures since I couldn't find any condensation damage on the MB. Possibly running the 4930K CPU at 1.6 volts for an extended period of Benching may have resulted in it's premature failure, Which all adds up to why I've been taking different ventures with cooling experimentation a little slower using just a single card.

  

Here's an interesting thought that I had not considered lately...........
 
Since I'm already near limits with my System (ASUS RVE/5960X at 4.8GHz/16GB Corsair at 2800MHz/NVIDIA Titan X at 1514MHz - 2005MHz Memory), I'm beginning to wonder how well Gran Theft Auto V would work (FPS) if I install it on my Benching Rig?
 

 
Maybe I can Find a way to "Download" a copy for Testing.
 
 
 

Scarlet-Tech
I have a question about Phase Change.  Three Questions actually.  
 
Scrap heap (in my sig) is under Phase Change right now. The head of the cooling plate is reporting -45c on the Fluke and -43 on the phase change itself.  The CPU isn't showing lower than -18 ever though.  Is that normal?  I don't want to start pushing until I am sure my temps are really good and ready to start. I only tested that for about a hour so far.
 
I also tightly packed around the socket, and then over the CPU, but I did not use DiElectric grease in the socket.  Should I use the grease since I will be using this as a daily driver once I get the system full up and running?  I have read that at the temperatures this is capable of, it may not be necessary.. I would rather take the safest option for long term exposure possible.

This is a Normal Temperature Swing condition for most Single Stage Phase Change setups.
 
On My 5960X running at 4.8GHz, My Phase Change shows -40C at the top of the evaporator head, But on my ASUS RVE OC panel, it is showing -9C to -12C while under Load during the First two of the Graphics Tests on Fire Strike Bench, But during the Physics and Combined Tests the CPU temps can rise as high as +22C due to the 300W Phase Change Load limit on my Single Stage Unit not being able to handle the additional Load of the CPU when Pushing extremely hard during those Bench Tests.
 
As far as Dielectric grease or even Petroleum Jelly in the CPU Socket, I would advise either one should be used IF you are going to operate your System for extended periods or 24/7.
 
In All my previous Phase Change Benching Rigs, I have used Petroleum Jelly in the CPU Socket that has been heated until it is melting using a Hair Dryer before then Installing the CPU in which the underside has also been lightly coated before it is locked into place followed by heating the CPU itself to ensure good electrical contact/moisture seal between the CPU and the Socket "fingers" before I will install the Phase Change Evaporator Head assembly.
 
It is Still up to the individual on whether or not to use any form of CPU/Socket Protection, But Judging from My Experience, This Method has NEVER caused any damage to any CPU/MB on any Benching Rig using Phase Change Cooling I have built since 2008.   
 
 

Scarlet-Tech
I will be pulling the cpu soon anyway, as I am considering a delid. Not sure if liquid pro has an appropriate thermal range for subzero. When I pull it, I will go ahead and warm up the dielectric grease since I have verified it works well. I guess I should ask if I should fill the socket or just lightly cost everything?

My temp of -18 was at idle, so I felt like it may have been high and just wanted to check.
 
Just found the answer to the thermal range for liquid pro.  -273c to 1200c. I think it will be fine, lol. 

I would be very careful that in the event you decide to use dielectric grease in the socket that you do not damage the "fingers" when applying it.
This is the main reason I have always used the previously mentioned method of melting Petroleum Jelly into the CPU Socket to prevent any damage, But Like I stated in my last post, Use whatever method is comfortable for yourself that works. 

hallowen

I would be very careful that in the event you decide to use dielectric grease in the socket that you do not damage the "fingers" when applying it.
This is the main reason I have always used the previously mentioned method of melting Petroleum Jelly into the CPU Socket to prevent any damage, But Like I stated in my last post, Use whatever method is comfortable for yourself that works. 

Delidded last night. Went through the procedure of removing all of the scrap epoxy, applied CLP, fingernail polish to the caps and fresh epoxy to to the ihs. Placed it in a spare board last night and clamped it to sit and cure.

Came home today, after grabbing Petroleum jelly, filled the socket and prepped the cpu, and installed it.

Boot into the bios, and I am at -21c now. That is only 3c difference, but I figure that every single c counts, so why not. Everything booted fine and I actually overflowed the socket a tiny bit by accident, but I figure that it's OK compared to not enough.

Ready to make this old girl my daily driver.

So far, just brief testing on the cpu. 5.2ghz at 1.45v. Trying to pull the temp and voltage down now. I can not see the temps through software once it hits 0. Anything below and it just stays at 0 or doesn't register at all.

Any tips on a program that I can see below 0, since the bios definitely reads down into the negatives?

Ah ha. OK, sounds good. I will stick with this for now. I pulled back to 50 multi and 101 bclk. At 5.2,it was hitting +16c on one core during Aida 64 extreme stress test.

I figure lowering the clock and temps is OK.

:-) I am not sure that the contact with the thermal material is perfect yet. I am also trying to get the voltage figured it as well. Since this is my first experience going this low, I figure I will take my time.

I am pretty sure that the wattage was supposed to be around 300w dissipation for this PC. I didn't think the 4790k would get into the positives. So far, I am at 5.0 ghz 1.409v. Still have more work to do.

As someone who has only read about phase and has not used or built them before, why is 300W the cap.  Can you make a SS that is 400, 450, 600W or is that impractical for some reason?  Too much power draw or too physically large?

Halo_003

EVGATech_DaveB
As someone who has only read about phase and has not used or built them before, why is 300W the cap.  Can you make a SS that is 400, 450, 600W or is that impractical for some reason?  Too much power draw or too physically large?

Well 300W is the load the phase is tested to cool. A higher load is possible but I think it would start to get very loud and very expensive quickly. A lot of SS units you see are mass produced with a 300W load. Custom ones yes you can get in the 450-500W range but it isn't cheap. At a certain point a single stage is no longer able to keep up which is why SS usually only cools to -40 to -50C on idle. They usually are tested to 300W load at -25C or so.
 
You can get a dual stage to cool 500W load at -75C, which would idle around -100 to -120C, but at that point you're talking massive power draw, extremely loud and power hungry, not to mention hella expensive. I'm not sure of if there's really a xxxW load limit that really can't be passed, just that usually units are built tested with a 300W load.

Very True Info, My dual stage Cascade I built in 2009 would idle at -100C+, But drop significantly under high benching loads, Not to mention as Halo stated above cost WAY too much to build, required a large electrical power draw and was very noisy under operation which are the reasons why I haven't thought about using it again.
At least with my present SS unit(s) I can still talk to other people in the room without raising my voice!