Thinkpads Forum

I shall be forgiven for following up on my own post:

Other than that, I have no idea. There is no way this "feature" can be intentional, much less useful. This is a serious bug that effectively prevents the machine from being used as a desktop replacement. I wonder what's going to happen when the battery cells are depleted, will I find myself with a laptop running a glorified dual-core Pentium 3?

Well, I got everything wrong, or so it seems. This "feature" is intentional, useful (if you sell battery packs, that is), and anything but new. Here it is, straight from the horse's mouth:

http://www-307.ibm.com/pc/support/site. ... IGR-4R4SC9

Symptom
ThinkPad A2x, T2x, 600X with Intel Speed Step microprocessor will slow down to Battery Optimized speed when the battery is removed from the machine.

Affected configurations
ThinkPad A20, A21, A22, T20, T21, T22, and 600X models with Intel Speed Step microprocessor.

Solution
This is working as designed. Please have the battery inserted to run the CPU at full speed.

Additional information
When operating at highest CPU speed and with high current usage peripherals attached (CardBus cards, USB devices, etc.), the required operating current may momentarily exceed the capability of the AC Adapter. When the battery is installed, the battery can supplement the power during the momentary peaks.

When the battery is removed from the ThinkPad computer, it switches to "Battery Optimized" speed (lower speed) to reduce peak power demands and to prevent the possibility of input voltage dropping too low, causing the ThinkPad computer to power off.

An interesting opinion, which I happen to agree with:

http://zurich.ai.mit.edu/hypermail/thin ... /0040.html

The fact that T20 will not run at full CPU speed (silly Intel SpeedStep) without the battery is a BIG conspiracy. This means you have to replace your battery once a yr even if you're on AC most of the time.

For some reason, my X21 is able to run at full CPU speed without the battery, but not my T20. I hope IBM can release a new BIOS for the T20 so that I can run at full CPU speed without the battery.

I think that a class action suit against IBM and/or Intel is a possibility
here.

Knowing what I know about Intel and their business practices, I strongly suspect ALL Thinkpads with Speedstep are affected, odl and news. I also venture the following assumptions:

- The batteries will inevitably die in (what) 1 year or so.
- At which point, the laptop will be locked at the lowest multiplier, unless:
- You put a new battery pack in it. However:
- Not any pack will do, just an original one (differences in internal circuitry) at $150 a pop.

I'd be glad to be corrected and proved wrong. I purchased this laptop to use it plugged in most of the time. Nobody told me I had to pay a Speedstep yearly tax to run it at the advertised speed.

Admin Edit: Trolling aspects of this post have been edited. You are free to sensibly express your opinion WITHIN the Rules of The Road for posting messages here, so please read them and comply!

You can get around this by using Kubuntu 7.10 instead of XP.

Tested all of the machines in my house (a variety of A3x, T4x, T6x) and when you set the mode to "performance" it will run at full speed even with battery physically removed.

Also, quite a few generic batteries will enable a ThinkPad to run at full CPU speed even under Windows.

ajkula66 wrote:You can get around this by using Kubuntu 7.10 instead of XP.

Here: http://forum.thinkpads.com/viewtopic.ph ... a5d3949425

"Tested" is kind of vague, what benchmarks are you using? I don't doubt what you say, but my compile times, BOINC scores and such tell a different story.

Gentlemen, this is going in circle and I've been called a troll, so it's probably time to leave it at that. This is my first Thinkpad; I researched the purchase carefully but the problem is so egregious and so old I'm surprised it has received so little attention. It hasn't been fixed in 5 years and I doubt it will ever be fixed.

At any rate I'm satisfied with the officlal pronouncement "when the battery is removed the machine reverts to battery optimized speed." Whether this explanation is Lenovo's attempt at surreal humor, I'll leave it for others to ponder.

Thank you all, the thing will be heading to ebay in short order.

By "tested" I'm referring to what Linux CPU meter shows you. I've found no reasons to doubt it this far, and I've owned more ThinkPads than most people on this forum. Think of a very high three-digit number.

I have found no workaround for the XP as of now. And it's quite possible that having the latest BIOS installed (I'm not big on updating, quite the opposite) can kill my Linux workaround. But that's the best I have.

Good luck with your intended sale should you choose to proceed with it.