Thinkpads Forum

I've been wanting to put an X61 T8100 (or better) motherboard into
an X61s or X61T for some time now, but of course people say that
the smaller heat sink cannot handle the extra power. I've noticed
that the Penryn's are clock for clock more efficient that the Merom's
that are used for lower power processors. I considered down clocking
a Penryn motherboard then remembered that the Power saving options
reduce the clock rate, this is what I've noticed on a 2.5GHz T9300 with
the same Santa Rosa chipset playing a 720p video:
Power Saver: Spends a lot of time below 1 GHz often at .8, blips to 2 GHz
Balanced: 1.5 to 2 GHz most of the time, .8 sometimes, never IDA 2.6 GHz
High Performance: 2.5 GHz most of the time, blips to IDA 2.6 GHz and
very infrequent drops to 1.5.
Seems to me that a T8100 (2.1 GHz) or T8300 (2.4GHz) should easily work
with the smaller heat sink as long as High Performance is not used, or used
sparingly. I most often use Balanced anyway.
Certainly this is far easier and better than a hard wired down clock.

Thoughts? I might give this a try.

I currently have an X61s will any heat sink that fits here also fit the X61T?

Passmark:
L7700 1.8 GHz 968 single thread 563
T8100 2.1 GHz 1301 single thread 830

Another way to look at this is that in Balanced mode with a medium to
light load it will probably be fine. When a heavy load comes along that
might cause it to overheat there is always the option to put it in Power
Saver just to keep the temps down. I think that most of the time the
system will feel much more responsive.

Pete B wrote:I've been wanting to put an X61 T8100 (or better) motherboard into an X61s or X61T for some time now

If I'm not mistaken you'll need a modded BIOS - and I'm not talking about Middleton's - in order to run a tablet with a "standard" X61 board.

but of course people say that the smaller heat sink cannot handle the extra power.

I would tend to believe this myself. Cooling was pretty ill-designed for these machines. Physical fit might be another challenge.

I've noticed that the Penryn's are clock for clock more efficient that the Merom's that are used for lower power processors.

This is correct, generally speaking, However, there's a caveat...read on...

Seems to me that a T8100 (2.1 GHz) or T8300 (2.4GHz) should easily work with the smaller heat sink as long as High Performance is not used, or used sparingly.

My concern would be that you're intent on replacing a LV CPU with the standard-voltage one in an environment that can barely deal with the heat dissipation of a LV CPU.

I most often use Balanced anyway.

I *never* rely on Windows to control power settings, but that's me.

I currently have an X61s will any heat sink that fits here also fit the X61T?

I'm inclined to say "no" but compare HMMs head-to-head and find out for yourself.

I think that most of the time the system will feel much more responsive.

Before you dive into any of this, I'd strongly suggest verifying that a "standard" planar will fit a tablet base...I can't say "yes" or "no" because I've never attempted the swap myself, but would be somewhat skeptical.

Good luck and keep us posted.

I take it that you use the Lenovo power manager, or?
Is there a particular revision that works best?

Thanks for all the tips, I was not aware that the tablet planar had a
different BIOS perhaps making this all moot.

Pete B wrote:I take it that you use the Lenovo power manager, or?

Yes.

Is there a particular revision that works best?

I don't know about "best" but my R61FL runs an older version, namely 3.04

Thanks for all the tips, I was not aware that the tablet planar had a
different BIOS perhaps making this all moot.

Not necessarily. There's BIOS which was made for people converting their X61 units with SXGA+ tablet panels, you'll just have to locate it.

However, physical fits of planar and subsequently heatsink would be major points of concern for me.

Good luck.

I've once done the opposite (put an X61 Tablet board into an X61s chassis). I had to force-flash the X61s BIOS onto the X61T board.

The major difference between the Tablet and the non-Tablet boards revolves around the LCD connector, which also contains the touchscreen, tablet button and Bluetooth module signals. If you try to plug a non-Tablet LCD cable on the Tablet board, it will immediately shut down when you press the power button.

As mentioned earlier, I had to force-flash the non-Tablet BIOS for it to work. The end result was a working board, but some of the indicator LEDs (battery, standby, charging, Caps lock and Num lock) don't light up. It's an annoying issue, which is why I don't want to do it ever again.

That said, I don't know if flashing the X61T BIOS on a normal X61/X61s board will work at all.

Bottom line: I'd rather not cross-pollinate with the Tablet models.

Physical fit is not a problem -- the tablet and non X60/X61 boards are physically compatible. The heatsink is another matter though-- the X60/61 has a taller heatsink which will not fit inside the X60s/61s and Tablet chassis.

Aside from clock speed control, I also suggest undervolting the CPU to further reduce the heat and power consumption.
The T8100 has a specified TDP of 35 watts (max power consumption 53w), while the L7500/7700 are 17w TDP (max 28w) -- that's almost double the heat and power output.

In Windows 7 Power settings, you can specify the min and max CPU clock speed (in terms of %), but the actual clock speed is limited by the available clock multipliers. For example, setting it to 5% on a T8100 won't give you 105MHz but 800MHz, because the lowest multiplier is x4 (FSB is 200MHz, so 200 x 4 = 800).

Thanks for the tips.
I was thinking of trying the T BIOS on a non T board doesn't sound like fun.
I wonder if the non T board is missing some connections on the motherboard for it
all to work. Do we have schematics of both available online?
Best would be to do a 1066 mod with a P series processor, but the CPU is soldered
in as I'm sure you know.

Yes, undervolting would probably also help a lot.

X61 machines, or boards, show up on ebay with T8100 and T8300 from time to time.

On the chineese forums there are always P8800's for sale.

The x61s fan will be fine with those processors for normal daily use but not for compiling or encoding video, or heavy processing. The x61 base has more space for air ventilation around the processor than the x61s or x61t base.

jaspen-meyer wrote: On the chineese forums there are always P8800's for sale.

I take it that the P8800s are processors that were done as a mod, 1066 FSB
and BIOS? I've seen mention that some even on here have access to equipment
for reworking BGA stuff. Or were you saying a bare P8800 CPU and not on an
X61 type motherboard?

I take it that most on here are aware of the young guy in NYC who does board
level repairs on Apple stuff but who also love's Thinkpads? Louis Rossmann
warning about his foul language:
https://www.youtube.com/watch?v=w57ObM3pYXw

He could swap BGA CPUs I'm sure, wonder what he would charge.

They're motherboards, or entire machines, with a P8800. Of course it requires you fiddle out the riddle of ordering from an individual in China.