X61 - Your power adapter may be cheating you! [ Edited ]

[ibm]

If you have a small format (65W) AC power adapter, your notebook may be underpowered and thus not giving you 100% of its performance.

A simple test may reveal that on some of the Lenovo notebooks, especially the ones equipped with a high end processor (tested on X61 tablet 7764-CTO Intel Core 2 Duo processor L7700 1.8 GHz), the small format (65W) AC power adapter is inadequate. This may happen primarily on custom configured notebooks, but it would not hurt to test yours as well.
In contrast, a 90W AC power adapter has the capability to bring your notebook to its full potential, sustaining the maximum Processor Frequency speed (100%).

Lenovo does not offer options and refuses to deal with the issue, as this looks like a gross and costly engineering mistake.

The test:
Remove the notebook battery and power your notebook only through the provided small format (65W) AC power adapter. Otherwise, as someone else pointed out, the battery will act as a big capacitor supplying extra current and the notebook will perform normally as expected.

How to get the performance parameters on your notebook:
A) If you have Vista, simply run the Resource Monitor tool (the button is available on the Performance tab in Task Manager). You may see that the Maximum CPU Frequency of your machine is reading 66% (not 100% as it should be). This is regardless of any OS and BIOS settings you may have (that is even if you have set your machine for maximum performance). You may also follow the directions specified below, as they are general and not just valid for Windows XP.

B) If you have Windows XP (or would like to run a more conclusive test), you can use any of these utility programs available for free (just Google and download it):    
1) Intel Processor Identification Utility (On the frequency test tab - Reported Core Speed will not get above 1.2 MHz)
2) CPU-Z (On the CPU tab - Reported Core Speed will not get above 1.2 MHz)
3) RMClock (On the CPU info page - Core Clock and Throttle will not get above 1.2 MHz)
4) SuperPi (This tool will not reveal directly the Core Frequency of your processor. However, being a very processor intensive program, you can actually time your machine when running with a fully charged battery attached and then without it - you may notice a difference in performance ~33%. For example try to calculate pi using a large number of decimals, like 1 Million).

Moderator Note: Edited subject to match content.

[wjli2]

the L7700 model are low voltage models of the Intel processor, it is designed for low power consumption, while the 12.1 inch LCD also consume lot less power.... the only reason why you need 90 W are for larger LCD, Nvidia graphics (not the Intel X3100 integrated model) and high speed cpu (T7xxx) series.. as 65 w is underpowered to charge the battery quickly in these models... if you don't have a large set of CPU intensive programs running, the modern core 2 duo cpu shouldn't have 100% running at all the time... it seems weird that the 65 w adapter is serving quite well the T61 and R61 series with x3100 at all states, yet it is underpowered for x61t with smaller screen and low power consumption cpu....

[erik Community SuperMod]

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ibm wrote:
If you have a small format (65W) AC power adapter, your notebook may be underpowered and thus not giving you 100% of its performance.

...

the small format (65W) AC power adapter is inadequate.

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can you provide a real-world example that would affect the majority of tablet users?   super pi, to me, isn't exactly something the average tablet user will be running.   have you tested any office or design apps?   have you tested on battery power at maximum performance versus plugged in using the 65W?


update: edited for clarity.

Message Edited by erik on 05-03-2008 08:19 PM

[ibm]

Lenovo Technical Support, Sales and Service have acknowledged the problem described in my initial post. I have presented a fact, which can be easily reproduced.
As a result, trying to convince people otherwise is futile.

For people who pretend not to get my point, I will try to present the situation in different words.

Keeping my notebook settings unchanged and simply booting with a different AC power adapter, I get different results:

Booting with the 65W AC adapter it takes Super Pi to calculate pi with 1 Million decimals more than 40 sec.
Booting with the 90W AC adapter it takes Super Pi to calculate pi with 1 Million decimals less than 30 sec.

Any processor intensive task I may run, the notebook will take more time to finish it when I use the 65W AC power adapter. The results are mostly visible when the notebook battery is removed, or when the battery is charging.

I have paid a premium to get the best processor offered with Lenovo X61 tablet (1.8 GHz), and by using the 65W AC adapter I end up with a performance below that of the cheapest processor in the series (1.4 GHz).

Lenovo does not want to hear about it. They have literally hung up on me and all I am trying to do is to bring awareness among potential buyers. Had I known about the way they treat customers, I would have avoided Lenovo entirely.

Message Edited by ibm on 05-05-2008 12:02 AM

Message Edited by ibm on 05-06-2008 01:09 PM

[wjli2]

if you would be so kind to run the following tests and inform us the result once you are done....

here are the test details:

http://www.thinkwiki.org/wiki/How_to_measure_power_consumption

[ibm]

I think I have already explained what the situation is.

Since Lenovo Technical Support, knows about this problem, maybe you should ask them to run these tests. I am not paid to do their research work, and they do not want to talk to me, period.

Meanwhile I have received reports from other Lenovo notebook owners that describe the same problem.
I encourage everyone owning a Lenovo small format 65W AC power adapter to run the test described in in my initial post. If they are willing, they may also help you continue your research.

My intention is only to bring awareness among people, especially potential buyers who need to be properly informed.
 

Note from Moderator:  Please read the Community Participation Rules found in the Welcome & FAQs section paying particular attention to the section prohibiting trolling, and adhere to them.
 

Message Edited by nonny on 05-04-2008 02:24 PM

Message Edited by ibm on 05-05-2008 12:09 AM

[wjli2]

if Lenovo would run the tests then you wouldn't be here would you???

[ibm]

My assumption was that this particular forum is run by Lenovo or under the close supervision of Lenovo people, since there is a direct link to it from Lenovo's main web page.

I am sorry wjli2, but currently I do not have the means to perform the tests described in your link. If anyone else is capable of performing these tests, please give us a helping hand.

Coincidentally, I have been asked by someone else to perform another set of tests and I thought you (and everyone else) might want to know the results. Here it goes:

1) Booted with the battery (no AC power adapter). OS started.
2) Plugged in the 65W AC power adapter and then removed the battery.
3) Ran Super Pi with 1 Million decimals once:            44 sec.
4) Ran Super Pi with 1 Million decimals second time: 43 sec.
5) Ran Super Pi with 1 Million decimals third time:     43 sec.
6) Attached the battery, then switched to the 90W power adapter and then removed the battery.
7) Ran Super Pi with 1 Million decimals once:            28 sec.
8) Ran Super Pi with 1 Million decimals second time: 28 sec.
9) Ran Super Pi with 1 Million decimals third time:     28 sec.
10) Attached the battery, then switched back to the 65W power adapter and then removed the battery.
11) Ran Super Pi with 1 Million decimals one (last) time: 43 sec - it never fails.

Note: No reboot was done between the sets.

Meanwhile I have been notified of trolling by the Moderator, and I invite him to clarify what words or comments I made that maybe I should be concerned about or revise. We are all learning here after all.

[JaneL Community SuperMod]

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ibm wrote:

Meanwhile I have been notified of trolling by the Moderator, and I invite him to clarify what words or comments I made that maybe I should be concerned about or revise. We are all learning here after all.

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I'm not a him.  You've got a PM.

[ibm]

This is what actually happened...

When I called Lenovo Technical Support in January 2008, reporting this problem, the agent I talked to, said the behavior was odd/wrong and they did not get any reports of this kind. He also said there may be something wrong with the motherboard and they may need to replace it (!).

Knowing there is nothing wrong with the motherboard, I told him I would like to try using a more powerful (90W) AC adapter. On the 25th of January I placed an order online for such an adapter. It "only" took 10 weeks and a formal complaint to be delivered.

After I have completed my tests with the more powerful adapter, I have called again Lenovo Technical Support (end of April 2008). This time a different agent acknowledged the problem , created a case number and told me I will receive a replacement adapter within 2 days.
When I asked him what type of adapter he was going to send me, he said he has no way of knowing, and that I have to wait and see.

One week later I called again to ask about the status of my case and got to talk to a different agent. He said there is no such case number under my name. I asked to talk to the supervisor of Technical Support, who told me this is not a warranty case, since the adapter is not defective, and I have to sort it out with Sales.

I called Sales right away and they said it's not within 30 days of purchase and I have to call Service. When I called Service , the person I talked to, told me this is clearly a case of Warranty and referred me to Technical Support. The new person I got to talk at Technical Support, checked with the supervisor and hung up on me saying there is nothing they can do about it.

When I get the chance I will tell you all about my experience with Lenovo Customer Complaints department.

Message Edited by ibm on 05-06-2008 04:55 AM