I think this must be my problem. It makes no sense in my brain that all 4 dies can run at 250mh but if I put them at 300mh they shutoff. In my brain either something is broken or not. So if they are not 100% broken, then why can they not run at 300mh. The only logical explanation is something is getting too hot that isn't being monitored by the software. And it shuts off dies when they get too hot, even though the Temps in the software are really low. Either that or something is short circuiting when they get too hot.

I felt the copper heatsink tubes and they are all pretty cool. Right now my temps are at 47C and 65C DCDC average temp. And 42C and 54 DCDC average temp on the cube running at 250mh. The last thing I may try is to see if the cover plate for the heatsink that goes over the copper tubes is too tall.

Ideally you have an aluminum plate that goes over the copper section that makes contact with the CPU. And this should be the same height as the copper tubes. Something like this # = Aluminum plate | O = Copper heatsink tubes
######
#OOOO#

But if this plate is too high or the copper is too short, then maybe the copper isn't touching the CPU properly.
######
#OOOO#
#         #
<with a gap at the bottom, if that makes sense>

Thanks TXSteve, the fans are stilling running and running fast, they are about 2 months old. Whats weird is my temps dont rise up and get hot. Like the main Temperature will show 55C and the DC/DC temps show a max temp of 75C and GenTarkin starts shutting off dies. (Previously before Tarkin, dies would just reboot and run for a bit and reboot and run for a bit). Then GenTarkin will say Dies 3.1 3.2 3.3 3.4 have been removed from health check.

Thanks Lightfoot I will check if the heat pipes are getting warm. I think the heatsink is making proper contact. I resurfaced it 4X using various thermal products. My temps dont get that hot, like 55C on main page and DC/DC average is 75C max.

It seems like something is shorting out when it gets slightly hot, like maybe metal is expanding in the heat and shorting. Haha I used to run this thing at like 90C-95C on the DC/DC temps and never had issues. I will keep playing around and see if I can figure anything out.

I noticed in PUTTY that Die Temps dont show up in there. It has a section for it called "hottest temperature", but its blank. I heard that KNC didn't program WAAS drivers or something to retrieve the die temps.

Does anyone have any ideas on what else inside a Titan could be getting hot and causing instability making dies shutoff or reboot. Something getting hot that isn't monitored or displayed in the ROM software?

I have 1 cube that is causing issues and often reboots dies and/or shuts off dies. I have 8 copper heatsinks on 8 little chips (not sure what these are called maybe the DC/DC?) I have the high powered Noctua fans. I resurfaced all CPUS (and on this problem cube I have tried Artic Silver, GELID and ARCTIC MX4). I sawed away most of the heatsink plate (to make room for copper heatsinks) and removed all that rubber greasy thermal stuff. I have GenTarkin ROM as well.

Even after all these mods this 1 cube reboots or shuts off. Even though the temperatures show 53C and 72C DC/DC temp. This is in a hot garage in Florida and the temps are way lower than the old days where the DC/DC would run at like 95C DC/DC temp. During the night this 1 cube can run fine at like 50C and 65C DC/DC temp. But once it gets a little hot outside issues happen. So there must be something "else" that is getting hot that isn't displayed in the ROM software. Any tips or ideas will be appreciated. If I login through PUTTY will that help? I did it years ago, but dont remember if there is anything useful in PUTTY / PI that may show the problems. Thanks All

I did some Titan modding using the info Searing provided.
1. Got some of those Noctua fans.
2. Resurfaced the CPU with some Artic Silver.
3. Sawed away most of the main heat sink plate to make room for some DC/DC heatsinks.
4. Installed 8 tiny DC/DC heatsinks per cube.
5. Removed the PCI power port plastic adapters and connect directly to the 6 pins.

I live in Florida and my Titan runs in a closed garage with no ventalation. Before the mod my CPU ran at 70C and my DC average temp was 95C. Post mod my CPU is 56C and DC average temp is 76C.

I was never too concerned about CPU temp, but my DC temps were really high. Getting rid of all that greasy thermal rubber and opening up the airflow seemed to help a lot. The DCs are running 19C/34F cooler now. Also I found out by accident that the cores will start rebooting once the DC temps reach about 110C.

Another question I have is can I replace my PCIE plastic power connector by just plugging in a new piece over top the existing pins? I pulled off the plastic PCIE ports on 1 cube leaving the metal pins behind. I found some new PCIE plastic ports online that do not have the pins embedded into them. So can I just plug these new pieces on to the old pins and be back to BAU? I haven't received the PCIE male ports yet. But it took me a long time to find the part without the pins embedded into them. So I am hoping this works, without going through the whole solder process.

I am having an unusual issue with my Titan, hopefully someone has an idea on how to proceed. 1 of my 4 cubes had the PCIE port fry and melt and it turned off. I removed this cube and ran on 3 cubes for awhile at a constant 240mhs with average heat. So I decided to reconnect the 4th cube and remove the PCIE plastic from the port and just connect directly to the pins that connect to the board. When I did this all 4 cubes got really hot within 3 minutes and dies started rebooting due to heat around 110C. I removed the 4th cube and the remaining 3 good cubes continued to get super hot and reboot.

So at this point I disconnected all cubes and booted up just 1 cube and it ran at 80mhs and heat was normal. But when I connected a 2nd cube both of them got super hot again. I then connected that 2nd cube by itself and it ran fine. Even the bad 4th cube ran fine by itself. For some reason any time I add more than 1 cube, all cubes get crazy hot. I tried using the reset button on the board and resetting it. I reflashed the card numerous times. I tried different data ports. Every cube works fine by itself on various data ports. But anytime more than 1 cube is connected they all get too hot to run. I am sooo confused, lol