X61 with quad-core should be feasible.

[Qing Dao]

I ran a few tests and did some calculations, and an X61 with a quad core should work out pretty well. A T9900 has been found to work, just barely, in an X61, so I used that as a baseline reference of the maximum power consumption/heat output that could possibly be supported by an X61. I have a T9900 in my T500 and its lowest voltage at stock clocks while remaining 100% stable is 1.1 volts. I don't know how many watts it is using, but that doesn't matter since the relative difference works out just fine as well. A stock Q9000 operates at 2Ghz, so I clocked the T9900 to 2Ghz and found the minimum voltage to be .9 volts. It could easily be lower, but I can't select any lower voltages in software. I searched online for references to Q9000 undervolting, but nobody was ever able to get very far because of being limited in software and nobody I could find had attempted a hardware undervolt. A Q9000 is the same stepping at my T9900, so it should perform similarly. Based on my own and others' experiences I could find with E0/R0 stepping mobile processors, it is safe to assume that almost any E0/R0 processor will work at .9 volts at 2Ghz. I use the formula voltage^2*frequency=power/constant to give us an indication of the relative power consumption. We don't know the constant so we can't know the absolute power consumption in watts, but as anyone mathematically inclined can see, it is good for telling us how the power consumption of two processors relates to each other. A Q9000 at 2Ghz at .9 volts consumes 87.5% of the power at full load of a T9900 at 3.06Ghz at 1.1 volts. And yes, that is taking into account that the Q9000 is four cores and not two. This still doesn't even take into account the possibility of undervolting it further and/or underclocking it.

Next there is the issue of the X61 processor being BGA and the Q9000 being PGA. I used to think that this was a major obstacle. However, BGA rework is something not only possible, but common place. A hot air gun is used to heat the chip so that the underlying solder joints are melted for both removing a chip and putting a new one on. You can see videos of the process on your favorite "tube" video website. The second obstacle is how to get a PGA processor soldered onto a BGA motherboard. The answer came to be completely unexpectedly. I wanted to upgrade my T500's processor to something not only faster but more energy efficient. An E0 stepping T9900 looked like a good choice, but it cost quite a bit more than slower processors. However, I found one for sale quite cheap. It is a BGA stepping processors that had pins added to it later. After receiving it, I was curious and closely inspected the pins, comparing them to the pins on the T9400 I removed from my T500. I had a eureka moment, the pins were exactly the same! The CPU packages were identical. For the BGA processors, Intel had soldered on balls instead of pins. If pins could be soldered on, they could be soldered off. Therefore, there is nothing physically stopping a Q9000 from being soldered onto an X61 motherboard.

A lot of work was done on getting the T61 to accept a quad-core processor. It has been done and for the most part works fine. The X61 motherboard is extremely similar, and the same modifications that were done to it can be done on the X61. In addition, a hardware volt mod for the processor will be required to bring the voltage down as low as possible, in relation to everything else, that is relatively simple and is something that used to be done all the time on desktops and video cards before voltage control became something done through software. The last piece of the puzzle, however, is the BIOS. For the quad-core processor to work on the X61, the BIOS has to be modified with the extra code that was required by the T61.

I've been thinking about this for the last couple of days, and I think it would not only work, but bring a lot of benefit as well. Single-thread performance may not be very high, but overall processing power of a Q9000 at 2Ghz is 30% more than a T9900. If one would be so inclined, a Q9200 at 2.26Ghz and .9 volts has the same power consumption of a T9900 at 1.1 volts. If one would favor battery life, a Q9000 operating at the X61's default 800Mhz FSB speed would run at 1.5Ghz. At a maximum undevolt, it would likely run cooler at full load than most of the stock X61 processors. Let me know what you think about this. I can't personally do the BIOS modification, but I will look into it. If the BIOS mod can be done, then I will fully commit and buy the Q9000 and a BGA rework station. I have a "new" X61 on the way that I ordered last night, and my old X61 is dead, so I can use the motherboard to practice on.

[Pokrzept]

IMHO you should consider one fact before taking this challenge. C2Q are nothing more but 2 Core2Duo integrated in one chip and forced to work as one. This means that you have to dissipate two times more heat than standard X61 running 2GHz C2D (lets say T8100). Even if you undervolt it, modify BIOS and add appropriate CPU microcode, do all soldering work to make it run on 1066 MHz FSB this is going to be straight way to melt your machine anyway.

[Qing Dao]

IMHO you should consider one fact before taking this challenge. C2Q are nothing more but 2 Core2Duo integrated in one chip and forced to work as one. This means that you have to dissipate two times more heat than standard X61 running 2GHz C2D (lets say T8100). Even if you undervolt it, modify BIOS and add appropriate CPU microcode, do all soldering work to make it run on 1066 MHz FSB this is going to be straight way to melt your machine anyway.

I already addressed that issue and it should not be a problem. A 2Ghz Q9000 at .9 volts will only put out about 25% more heat at load than a stock T8100. I'm not saying it will run cool, but what I am saying is that both the X61's power circuitry and heatsink can handle it. 2Ghz is a pretty slow speed, and E0/R0 stepping processors can undervolt really well. The undervolt will be done with a variable resistor on the motherboard itself, otherwise, yes, it will very easily overheat before loading the OS.

[axur-delmeria]

2Ghz is a pretty slow speed, and E0/R0 stepping processors can undervolt really well.

We all know there are individual variances when it comes to undervolting-- two Q9000s CPUs from the same batch will undervolt differently. You may have to get two or more Q9000s and test them till you find one that undervolts best.

A 2Ghz Q9000 at .9 volts will only put out about 25% more heat at load than a stock T8100.

25% is still a lot of extra heat IMO. Depending on the ambient temperature, the heatsink might not be able to keep up-- I mean, I had to undervolt my X61 T8100 because I was hitting over 80c at full tilt.

If there's an "economy mode" that disables the 2 extra cores, I'd be more supportive of this mod. The X61 already has a less-than-spectacular battery runtime; putting in a quad core would probably cut its battery runtime by at least 30%.

The other challenge is finding a way to increase the heatsink's cooling capacity-- hybrid cooling (heatsink + watercooling assist) comes to mind, as someone had done on the T61 before.

[FryPpy]

This is only teory that must be proven by practivce...

heatsink can handle it.
2Ghz is a pretty slow speed, and E0/R0 stepping processors can undervolt really well.

If you have read original C2Q thread you have found that heat was the problem on T61. Yes it was made for QX9300 that can generate more heat than Q9000, but T61 have bigger HSF. I very pessimistic about even Q9000 at 2GHz in X61. If you want to underclock and undervolt Q9000 i think it become useless. P8700, P8800, P9600 and even P9700 can be better in terms of power consumption vs computing power.
Some more hints - any C2Q have no SLFM - no power saving when idling.
If i don't mess - something some Q(X)9200 have bug with voltage regulation.

If i were you - ill wait till summer and wait for X62 mainboard. It is certainly that X62 mainboard not will be cheaper than Q9000 but i belive that it can bring more computational power and will be more stable.

[RMSMajestic]

Based on my experience of upgrading QCs in my T61, NO. Due to the following reasons
1. on my X61, a T9300 reaches 85 degrees celcius under IBT. It reaches 75-80 degrees celcius even when undervolted to 1.0625V
2. Although intel stated that QCs draws only 45W, the actual power consumption is so much higher. I've recorded 112W for the whole T61 with Q9100 without overclocking/IDA under IBT.
3. As you can probably tell from the absence of P9700 X61s, it is extremely difficult to solder a PGA CPU onto X61 cos those PGA CPUs has much larger pads
4. Even if you succeeded in solder a PGA CPU onto X61, it will be extremely hard for you to get the other two cores working (refer to the T61 QC thread for more information)
5. Theortically a Q9000 might work on X61, however a Q9000 doesn't perform any better than T9900 in most cases
http://www.notebookcheck.net/Mobile-Pro ... 436.0.html
Here a Q9000 has even lower rank than T9600

[axur-delmeria]

Although intel stated that QCs draws only 45W, the actual power consumption is so much higher.

To be more precise, it's 45W TDP -- Thermal Design Point. From what I gather, it means that the cooling system must be able to dissipate 45 watts in order to run the processor within its thermal limits. Maximum power consumption is in the order of 70+ watts, according to cpu-world.

[E350]

Qing Dao: Go for it. *

FryPpy: What is the X62 mainboard?

Edit: Wow! Miss four or five months here and big things happen. Yes, I too am interested in the X62 mainboard. In fact, one of my first posts, like other first posters I am sure, was whether or not another motherboard could be fitted to the X61_ series. I have X61s, X61T and X61 (two of each) but my two X61 are my favorites, the X61s does not have the processing power and the X61T always seem to be a little glitchy. I will watch the following thread with interest:

http://forum.thinkpads.com/viewtopic.ph ... 9&start=30

* That said, I should mention that while trying to write this post, after working all day on my X61 with it burning my lap, I had a full thermal shutdown. No BSOD, just immediate Black Screen. I was doing some drywall repair last month and I need to take the keyboard off and blow the dust out of everything.

Is there a way to take a docking station/port replicator, and gut it and install it permanently to house and provide whatever additional cooling would be required to do the various mods like usb3, quadcore, hdmi graphics output, etc.?