I've been thinking about trying to mod that silly heatpipe design that is on my 780i board for a while now. The biggest issue is that the northbridge cooler covers both the SPP and NF200 chip. This causes the board to have custom mounting brackets, so you can't just replace the whole thing as there aren't any custom coolers other than a few waterblocks.
I took this guys advice and just went to town on the heatpipe and cut it right off. It only took about 10 seconds for the hacksaw to make it's way through. http://chris123nt.com/2008/02/27/evg...t-cooling-mod/
Cooling the Northbridge isn't really the issue, it's the MCP (Southbridge) that was idling at about 65C in windows, and about 57C in the BIOS.
This time I did remember that pics are really useful for something like this, so I grabbed my mom's digital camera. It's not the best but it took some okay pictures which makes it a lot easier to explain.
First pic is the Old heatsink after I cut it apart. It's sitting next to an evercool VC-RE VGA cooler. http://www.newegg.com/Product/Produc...82E16835119080
I bought this originally to cool my DFI-Expert board's chipset, so I figured it would work fine for this as well. (After I took it off of the DFI board.
If you look closely you can see where the mounts are for all 3 chips. I already cleaned the TIM off of the MCP area so I could put it into a vice. This board is a revision 3 btw. You can see that the pads are on 4 corners for the SPP (NB) and MCP. One of the issues with the older revisions was the pad went all the way around the chip like it does on the NF200. If the pad was off part of it was actually on top of the chip causing some of the cooling issues since it didn't make good contact.
I redid the TIM on my other 780i board which is a revision 4. It made almost no difference which is why I decided to hack my this one. Both coolers seemed to be mounted pretty well, so there weren't any gains by remounting the heatsink. One more thing I'll point out, on the Revision 4 there is actually little grooved boxes in the cooler where all of the chips are supposed to be. I'm assuming it helps with correctly placing the pads as it creates a pretty good idea of where each chip will contact the cooler.
I labeled each part so it's easier to understand what I'm talking about.
The Evercool fan has worked pretty well on my DFI board, and I looked through some reviews and they said it worked well on 680i and 780i boards. The only issue is that it's a little tall and a long card like my 8800GTX doesn't completely clear a couple of fins. So what I did was bend four of the fins down some toward the mounting pin. Then I took and slightly bent 3 of them the other way. This gave it enough clearance where it's shouldn't touch the bottom of the PCB on the 8800GTX.
Enough text yet? I'll keep going.
I'm sure you're curious what's inside of the heatpipes going to the MCP. Well as far as I can tell there really isn't anything going back and forth as it's almost closed right off. It's just 2 copper pipes that are smashed closed and have some stuff over top of them. It's not a very good pic but it kind of gives you an idea of what it looks like.
Here's what they look like after cleaning them with ArtiClean. You can also see how smooth the base is on that Evercool, trust me, it's flat. The 2nd pic is after applying some of the Zalman STG-1 on the MCP. It made pretty good contact, but I smoothed it out again just to make sure I have enough coverage. I used Artic Silver Ceramique on the NF200 and the SPP because with those pads on there I don't think STG-1 would be thick enough to make good contact.
Here it is installed. I also replaced that noisy stock fan for the northbridge with a 70mm slim fan I took out of a water cooling unit I had lying around. It's not exactly the best mounting (a pair of twist ties) but it will work until I can come up with something better. I had an 80mm fan by it before but it doesn't fit under the TRUE's middle heatpipe, so this worked better.
Here's a good closeup of the fins I bent and what the edge of the heatsink looks like now. I did file it a litte, but didn't do much else.
Here's the final verdict.
I wrote down some numbers of what I recall the temps being before and after.
I was showing about a 10C drop in an open air environement while in the bios. The northbridge didn't seem to change much, but the fan is a lot quieter. Keep in mind the ambient temp was about 80F or 27C, so I'm sure that had an influence as well.
In windows using Everest I was seeing almost 65C for the MCP just idling on the desktop. This looks a lot better now.
I don't have any load numbers yet but I can already bet they should be considerbly lower than before. I'm hoping this will help with overall stability as I can pass P95 and Intel Burn-In at 3420mhz, but there will be an occasional issue gaming at anything over 3200mhz. My thought is that once both GTX's start dumping heat into the case that the MCP gets kind of warm under the cards. I won't know if this really helped for stability until I use the pc for a while, but it definitely helped lower the temps.
Speaking of which, I have a Stacker 830 with a window mod and 2 x 120MM fans that blow air onto the top gfx card and the northbridge. They barely clear the TRUE so I can get the door on. The wiring is a little messy but it will get straightened out better another day.
FYI This pic is upside down.
It's a little close, but you get the idea.
If you're still reading this I feel sorry for you.
Hope someone found it useful or interesting. It was a fun little project but I'm pretty sure the warranty is void now.