der8auer

After changing the stock TIM on Ivy Bridge CPUs we saw some impressive improvement for 24/7 setups using air- and watercooling. I could also improve my CPU for wPrime on LN2 and hit the 2nd best score in wPrime32m (meanwhile dropped down to position 3). Source: Thread http://forum.hwbot.org/showthread.php?t=47539 Unfortunately not everybody had the same improvements and also my CPU died few days later on air cooling. Even though I'm not sure whether the TIM change caused the malfunction. After the disappointing results of the TIM change I thought long about realy soldering the IHS back to the CPU like Intel did it in the past. This thread will be my worklog for this task. I will keep updating this thread during my testing. Let's start! 1. Theory: Why soldering? During my huge TIM roundup I also did tests at -150°C monitoring the delta temperatures between IHS and pot. Additionally I kept CoreTemp open. After each test at -150°C I had to heat up the pot and I used wPrime1024 for that. At only 1,5 vCore CoreTemp already showed positive temperatures at a pot temperature of -110°C. Usually we bench at 1,8-1,95 Volt on LN2 and on Load I'm pretty sure the CPU core will also hit positive temperatures very fast. Replacing the TIM we could lower the temperature by about 10 Kelvin but often the maximum clock was lower in the end. Unfortunately I have no explanation for this. At the moment I can not foresee whether soldering will change this behavior. That's why I want to try it Limitations Temperature Part 1: I know 99% of you are pretty experienced in soldering so you know that most solder will melt at 250-350°C depending on the alloy and purpose. Furthermore you know that these temperatures will kill your CPU for sure. So how can you even solder these CPUs? Studying the Intel datasheets I found some interesting information. Intel does not recommend to store the CPUs over 125°C. Checking for the materials used for the CPU itself I found that they are using normal fiberglass PCBs with gold plated pads on the bottom which are soldered at about 200°C. Temperature Part 2: At which temperature does the CPU realy die and why? The CPU is made of Silicon, Silicon oxide, copper, gold, silicon nitride and other chemicals you need for the layering process. Silicon is a semiconductor at room temperature but it gets 100% conductive at high temperatures. Depending on the doping of the semiconductor a CPU can already become fully conductive at around 120-130°C. Once this happens you have a short at some place and your CPU is dead. However if you don't apply a voltage to your CPU it can resist higher temperatures without any problems. Limiting temperatures: - PCB ~150-180°C - Silicon 200°C + - Soldered pads on the PCB ~200°C Solder The IHS is made of nickle plated copper and the DIE is made of silicon. The top layer of the DIE is not conductive so its either a layer of poly-silicon, silicon oxide (SiO2) or silicon nitride (Si3N4). Either way I had to find solder which is able to merge both components. The key is Indium. Indium is a very very expensive noble metall which melts at about 155°C and it sticks to almost every material. It's condictive and often used for semiconductors such as photovoltaic cells to connect wires to the silicon. After some hours if google-action I found a company which was able to create Indium solderpads for me. With a price of ~500€/kg for raw indium this wasnt a cheap order but anyway did it. I could select different Indium alloys which include tin, silver, bismuth and other stuff. Unfortunately the company could not tell me which alloy would be the best as I don't know the top layer of the CPU DIE exactly. The temperature range of these alloys went from 110°C up to 175°C. So pretty much in the temperature range we figured out above. Flux? Usually soldering tin has already flux included or you use a additional flux for easier soldering. I also got 4 different fluxes to test which one was best for me. 2. The real deal Of course I don't want to ruin my good 3770K straight so I ordered some Pentium G1610 which costs about 35€ per piece. The DIE of it is a bit smaler but should be good enough to test whether it works. So here's the Pentium G1610. Note: you can click on the images to view the full size I did a quick test on air first to check whether CPU is alive and which core temperature it will reach after few minutes on Prime95. Average temperature with stock TIM was 45°C and 47° max. Now I cut off the stock IHS and cleaned both - IHS and DIE with acetone. The Indium is very thin and ductile. I noticed that the fat from your fingers already completely ruin the result. So I'm using a pincette to place the soldering pad I'm using 0,125mm thick Indium pads which I can stack if I need a thicker layer between IHS and DIE. I used my dead 3770K first to check which alloy is the best to connect silicon and nickle plating of the IHS. I have 4 different alloys such as In97Ag3 or In52Sn48 or pure In which all have different melting points and heat conductivities. TBD: Add table with different alloys and thermal conductivities During soldering the dead 3770K I noticed that it's realy difficult to place the IHS on the DIE in the correct position. So I thought of creating something to fix the IHS on the PCB/DIE. The solution was quite simple I took a old board which I don't need anymore and cut off the socket. So now I have a pretty neat gadget to place and fix the CPU inside the socket enough for now More tomorrow!

Count me in for GBT OC event

okay waiting for the retail price

depends on the price. I'll have to pay 19% taxes importing this stuff so I'm not sure whether that's a good idea.

yea these are the real clocks. Look at estimated boost in inspector

Not sure if Beier hacked the account of Leeghoofd

80 is official maximum

Thx guys Got them online

@ Stavros: 6805 is absolute maximum for 1M so 32M is not that far. Maybe I can push another 20-30 MHz but not more. Here's my 3D so far. No vMem mod done and had issues with the memory when card was cold. Will try again tomorrow to see whether it can do more if it's modded. [HWBOT=2378044]submission[/HWBOT] [HWBOT=2378047]submission[/HWBOT]

well done

CPU is quite at its limit. Funny tho that I can't go higher than 1,82 Volt. Once I use 1,825 Volt or above it results in a BSOD [HWBOT=2377814]submission[/HWBOT]

Here's a quick preview of Christians shirts:

Nice work there, Vince!

Thanks for you support and the awesome titan mod thread btw Thanks I will rebench tomorrow. We had a lot of trouble until we noticed that we didnt properly fit in the SATA cable and killed our windows 2 times That's LiquidTape. You can find it here: http://www.der8auer.com aiming for top 9 like everybody else haha

Did you know that there are different PCB revisions out there? mine doesnt have the small extra PCB for the vMEM part. Was not an issue to find the 3,5k resistor but still surprising

Some more pics

My phone provider offers a internet flat for foreign countries for 1€ / day

So like always we'll see the best results ~2 min before the competition ends

Damn literally cool pics

¯\_(ツ)_/¯

No change without. Not even with 2 cores without HT.

No sandbagging here CPU is realy that crappy. Also slow mode didnt help.

Thanks to the AwardFabrik team and ASUS for hosting this nice event! I uploaded about 70 pics to this album: