Power supply - can I use 90 watt with a 65 watt T61

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EOMtp · #31 Post by **EOMtp** » Thu Dec 13, 2007 8:17 am

efrant wrote:Plugging a multitude of USB devices into your Thinkpad (without a dock) could dramatically increase power consumption (past 65W), even if the T6x/p runs fine on a 65W adapter by itself.

Absolutely correct. I don't think there is any disagreement about the fact that all these notebooks run perfectly fine with a 65W adapter if nothing external is connected to them. Once one begins to connect devices -- from USB devices to docking stations to PC cards, and more -- one has to start paying attention! ... and for those who do not want to think about "paying attention", the solution is to use a 90W adapter.

uberT · #32 Post by **uberT** » Thu Dec 13, 2007 8:28 am

While I always make it a point to 'pay attention', I just ordered the 90W unit. Nothing wrong with having a little reserve.

Thanks, guys!

efrant · #33 Post by **efrant** » Thu Dec 13, 2007 10:09 am

Take a look at this site: http://www.polarpower.org/technologies/ ... index.html

It indicates that the peak power consumption of a T60p is 52W for "simple computer operations". (I'll keep looking for more info.)

By the way, I just looked at the HHM for the T60p. If you open the pdf file to page 211, you will see that the 65W adapter is listed as an adapter for the following models:

2-pin (65 W, 20 V) adapter: 1951, 1952, 1953, 1954, 1955, 1956, 2007, 2008, 2009, 2613, 2623, and 2637 (models CTO, xxE, xxF, xxJ, xxL, xxP, xxS, xxY, xxU)

...

I will keep digging.

Roadster · #34 Post by **Roadster** » Thu Dec 13, 2007 11:04 pm

efrant wrote:By the way, I just looked at the HHM for the T60p. If you open the pdf file to page 211, you will see that the 65W adapter is listed as an adapter for the following models:

2-pin (65 W, 20 V) adapter: 1951, 1952, 1953, 1954, 1955, 1956, 2007, 2008, 2009, 2613, 2623, and 2637 (models CTO, xxE, xxF, xxJ, xxL, xxP, xxS, xxY, xxU)

I'm a little confused. My Hardware Maintenance Manual (HMM) only has 151 pages, so I can't refer back to the section you identified.

I just checked Lenovo's Worldwide Option Compatibility Matrix, and it contains a footnote (17) in the "T60" and "T60/p" columns on the row labeled "Thinkpad and Lenovo 65W AC Adapter, Part No. 40Y7696".

Footnote 17 says the following: "17. 65W AC adapter supports models with integrated graphics only. Those with discrete graphics should use the 90W AC adapter."

While I can personally verify that the 65W adapter will work on my T60p, because I keep one in the living room next to the coffee table when I want to work on the computer while watching college football games, it does get a mite warm (OK, actually pretty hot to the touch) when running anything that is graphics intensive (e.g., video games).

In light of this, I decided to start carrying my spare 90W adapter with me when I travel. In retrospect, the 90W adapter isn't nearly as big as I thought, and it's a hell of a lot smaller than the brick that I used to carry with my old Toshiba Satellite laptop. Now I hardly notice it, and I am pretty happy with my decision.

I'm giving my spare 65W adapter to my daughter for Christmas, so she can use it as a spare for her new X60 (with integrated graphics).

efrant · #35 Post by **efrant** » Fri Dec 14, 2007 1:00 pm

Roadster wrote:I'm a little confused. My Hardware Maintenance Manual (HMM) only has 151 pages, so I can't refer back to the section you identified.

We obviously have different models of T60p's. Mine is a 2008-93U, and its HHM is located here: ftp://ftp.software.ibm.com/pc/pccbbs/mo ... 844_02.pdf

That HHM says that the 65W adapter is fine with my model.

You have a 8741-W1C, which is not covered by the same HHM as mine is...

Roadster · #36 Post by **Roadster** » Fri Dec 14, 2007 11:07 pm

efrant wrote:
Roadster wrote:I'm a little confused. My Hardware Maintenance Manual (HMM) only has 151 pages, so I can't refer back to the section you identified.
We obviously have different models of T60p's. Mine is a 2008-93U, and its HHM is located here: ftp://ftp.software.ibm.com/pc/pccbbs/mo ... 844_02.pdf

That HHM says that the 65W adapter is fine with my model.

You have a 8741-W1C, which is not covered by the same HHM as mine is...

You're right. They are different HMMs. Mine is the widescreen model...

http://www-307.ibm.com/pc/support/site. ... MIGR-66958

(What was confusing me, besides the page numbers, was your use of a slightly different acronym... "HHM"... which led me to believe you were referring to a different type of document.)

Anyway, I noticed that your HMM covers both the T60 and the T60p, like mine does, so it would make sense that both the 65W and 90W AC adapters are listed.

Refer also to the Accessory Compatibility Matrix spreadsheet on the following URL...

http://www-307.ibm.com/pc/support/site. ... ACCS-GUIDE

Note Row 384 of the ThinkPad worksheet, and also Note 17 on Row 504, and you'll see the text that I was referring to in my previous post.

#37 Post by **erik** » Fri Dec 14, 2007 11:45 pm

per the accessories document linked by Roadster above, the official standpoint of lenovo reads, "65W AC adapter supports models with integrated graphics only. Those with discrete graphics should use the 90W AC adapter."

while it is possible in some cases to use the 65W adapter with discreet-graphics model thinkpads, anyone asking the question of which adapter to use should be made aware of the above statement.

efrant · #38 Post by **efrant** » Sat Dec 15, 2007 8:22 am

Roadster wrote:(What was confusing me, besides the page numbers, was your use of a slightly different acronym... "HHM"... which led me to believe you were referring to a different type of document.)

Sorry about that, it was a typo!

Roadster wrote:Anyway, I noticed that your HMM covers both the T60 and the T60p, like mine does, so it would make sense that both the 65W and 90W AC adapters are listed.

Yes, it is for both the T60 and T60p, but is specifically says the 65W adapter is for the xxU model, which is what my T60p is.[/quote]

Roadster wrote:Refer also to the Accessory Compatibility Matrix spreadsheet on the following URL...

http://www-307.ibm.com/pc/support/site. ... ACCS-GUIDE

Note Row 384 of the ThinkPad worksheet, and also Note 17 on Row 504, and you'll see the text that I was referring to in my previous post.

I completely agree that there are references elsewhere saying the the 65W adapter is not appropriate for the T60p -- but there are references that say it is as well.

Bottom line is while it is ALWAYS safer to use the 90W power supply (heck, if you want to be really safe, find or make yourself a larger one... in case you want to plug a gazillion external devices into your T60p, as the bigger you go, the safer you are, right?) many of us have been using the 65W adapter on a T60p for a long time, with ZERO problems.

The only way to end the debate is to measure the current drain from a T60p running at full load. Give that there has been so much back and forth on this, I will try go to Canadian Tire today and buy one of those wall plug-in current meters and test out my T60p, and report back.

Roadster · #39 Post by **Roadster** » Sat Dec 15, 2007 10:28 am

efrant wrote: Yes, it is for both the T60 and T60p, but is specifically says the 65W adapter is for the xxU model, which is what my T60p is.

efrant wrote: I completely agree that there are references elsewhere saying the the 65W adapter is not appropriate for the T60p -- but there are references that say it is as well.

I agree that there are conflicting references. In fact, I found another set of documents which conflict with Footnote 17 of the Option Compatibility Matrix.

Here's one covering your model type, 2008:

http://www-307.ibm.com/pc/support/site. ... MIGR-62743

And here's another covering my model type, 8741:

http://www-307.ibm.com/pc/support/site. ... MIGR-68410

These two documents clearly state that both the 65W and 95W AC adapters are supported on the T60 and the T60p.

Since my machine was delivered with the 90W adapter, and I got another 90W adapter when I ordered the Advanced Mini-Dock, I will continue to use the 90W adapters for home and travel -- especially since the 65W adapter that I bought as a spare gets so much hotter when running graphics-intensive applications -- and I will pass the 65W adapter to my daughter to use as a spare for her X60. (Her machine was delivered with a 65W adapter anyway.)

Nevertheless, it is good to know that I can always use the 65W adapter in a pinch if ever lose my travel adapter or accidentally leave it behind at a hotel or client office.

When you conduct your current drain test, I would still be interested in hearing the results.

Cheers!

#40 Post by **erik** » Sat Dec 15, 2007 11:22 am

efrant wrote:Yes, it is for both the T60 and T60p, but is specifically says the 65W adapter is for the xxU model, which is what my T60p is.

what came with your T60p; a 90W or a 65W?

Roadster wrote:<snip> Since my machine was delivered with the 90W adapter </snip>

and that makes sense. fwiw, i have yet to see a 'p' series T60/T61 ship with a 65W adapter. to me that speaks more loudly than any documentation since typographical/specification errors are easy to make.

efrant · #41 Post by **efrant** » Wed Dec 19, 2007 9:06 am

erik wrote:what came with your T60p; a 90W or a 65W?

Mine came with a 90W adapter as well.

erik wrote:fwiw, i have yet to see a 'p' series T60/T61 ship with a 65W adapter. to me that speaks more loudly than any documentation since typographical/specification errors are easy to make.

So because you haven't seen a T6xp shipped with 65W adapter, that should mean that it is not safe to use one with it? I would tend to disagree with that logic.

By the way, I did go out to try to buy a plug-in current meter (like this one: http://www.p3international.com/products ... 00-CE.html) over the weekend, but I could not find one in any of the three stores I went to. I will keep trying to find and purchase one, as I am sure we are all interested in the results.

#42 Post by **erik** » Wed Dec 19, 2007 11:55 am

efrant wrote:So because you haven't seen a T6xp shipped with 65W adapter, that should mean that it is not safe to use one with it? I would tend to disagree with that logic.

i said nothing about these statistics reflecting upon the "safety" of using a 65W adapter on a 'p' model. i said that there has to be a good reason why all 'p' models i've seen or used (40+ T60p/T61p units) have shipped with 90W adapters regardless of what IBM/lenovo documentation says is compatible. whether the 65W is "safe" or not is still up for debate.

i'd bet that no 'p' model has ever shipped with a 65W but would love to see definitive proof to the contrary just for my own knowledge.

efrant · #43 Post by **efrant** » Wed Dec 19, 2007 12:06 pm

erik wrote:i said nothing about these statistics reflecting upon the "safety" of using a 65W adapter on a 'p' model. i said that there has to be a good reason why all 'p' models i've seen or used (40+ T60p/T61p units) have shipped with 90W adapters regardless of what IBM/lenovo documentation says is compatible.

i'd bet that no 'p' model has ever shipped with a 65W and would love to see definitive proof to the contrary just for my own knowledge. whether the 65W is "safe" or not is still up for debate.

I guess I misunderstood your statement. I just assumed that by you saying:

"i have yet to see a 'p' series T60/T61 ship with a 65W adapter. to me that speaks more loudly than any documentation since typographical/specification errors are easy to make."

that you meant the 65W adapter was not meant to work with the 'p' models (and hence, not safe). My apologies.

I would, as well, speculate that all of the 'p' models ship with 90W adapters. However, I have never argued to the contrary; nor do I intend to.

Kel Ghu · #44 Post by **Kel Ghu** » Wed Dec 19, 2007 3:17 pm

The only time I heard the power supply not being capable enough was when people put a high-end graphic card in the advanced dock.

I have used my T60p with the 65W adapter without any problem and I am a gamer. My T60p used to draw 12-14W when on battery with low power settings. I never use max perf profiles when surfing or doing light apps. I think I have tried using my battery once with all the stuff at max and without any power managing, it gave me something like 52W with an USB mouse connected. But it was like a year ago.. I can't remember well.

let me try with my T61p.

Kel Ghu · #45 Post by **Kel Ghu** » Wed Dec 19, 2007 3:30 pm

OK, just tried playing Crysis on battery with CPU and GPU at max speed with a Logitech MX510 mouse connected.

Wattage
Average: 69W
Peak: 74W
Lowest: 65W

According to Lenovo's Power Manager. I think the FireGL V5200 draws less power.

efrant · #46 Post by **efrant** » Wed Dec 19, 2007 3:34 pm

Kel Ghu wrote:OK, just tried playing Crysis on battery with CPU and GPU at max speed with a Logitech MX510 mouse connected.

Wattage
Average: 69W
Peak: 74W

According to Lenovo's Power Manager. I think the FireGL V5200 draws less power.

Wow! You can actually play Crysis on a Thinkpad?!?

That's pretty cool. Didn't think that would run on anything less than a couple of 8800GTX's in SLI!

Anyway, how did you measure the power consumption? Playing Crysis should be pretty close to maxing out the CPU and GPU of your Thinkpad, so that should be a good gage of peak power consumption.

Edit: Nevermind my question. I just reread your post. It would be nice to confirm the Lenovo Power Manager results with an current meter though.

Kel Ghu · #47 Post by **Kel Ghu** » Wed Dec 19, 2007 4:03 pm

My GPU is overclocked. I went from stock speed 475/700 to 660/1000 (CPU/MEM). And it's playable and nice.

Something that is absolutly certain is that the T61p draws more than 65W during playing session. But I am also pretty certain that the 65W power supply safely supports more than 65W, something like 20% more. But Lenovo has certified it at 65W for added safety purpose.

efrant · #48 Post by **efrant** » Sat Dec 22, 2007 8:46 pm

Ok, I just bought myself a current meter. Does anyone have any suggestions for software to max out the cpu/gpu fully to do a stress test? I want to fully load everything and see how much current is actually registered on the current meter.

#49 Post by **jdhurst** » Sat Dec 22, 2007 9:07 pm

A Windows 98 machine started in VMware but not logged on and left like that will drive the CPU to max and stay there.

How will you measure current? You would need a special adapter to plug into the TP with wire ends to make the connections.
... JDH

efrant · #50 Post by **efrant** » Sat Dec 22, 2007 9:15 pm

jdhurst wrote:A Windows 98 machine started in VMware but not logged on and left like that will drive the CPU to max and stay there.

I will try running one instance of S&M (from here: http://www.benchmarkhq.ru) and two instances of rthdribl (from here: http://www.daionet.gr.jp/~masa/rthdribl/) to stress both the the CPU and GPU, as well as having the battery charging and a DVD playing. That should prety much max it out.

jdhurst wrote:How will you measure current? You would need a special adapter to plug into the TP with wire ends to make the connections.
... JDH

I bought myself one of these http://tinyurl.com/374f2u It plugs into the wall, and measures how much current is being drawn.

Roadster · #51 Post by **Roadster** » Sun Dec 23, 2007 1:57 pm

efrant, thanks for your follow-up. I look forward to seeing the results of your tests.

efrant · #52 Post by **efrant** » Sun Dec 23, 2007 10:18 pm

Ok, just had time for one quick run. If I'm reading the meter correctly, it looks like my T60p (with a T7400) under full load, simulated by the following conditions:
1) both cores running at close to 100% load;
2) the GPU running 4 instances of rthdribl (which I believe is max's out the GPU);
3) the battery charging;
4) a CD playing;
5) the wi-fi card transmitting 802.11g;
6) the BT radio transmitting; and
7) the screen at full brightnes

sucks back a max of about 100W! (Now if this is accuarate, it would mean that the 90W adapter can handle more than 90W, as I did not see any drop in voltage under max load.)

Over the next few days, I'll try to conduct various other runs which are more realistic of normal use and I'll report back.

EDIT: Edited for grammer.

blackomegax · #53 Post by **blackomegax** » Sun Dec 23, 2007 10:29 pm

The wall is a very innaccurate place to monitor, since AC has to be converted into DC.
The power supply has an effeciency of maybe 50-60%.

meaning for every watt the laptop pulls, the power supply is pulling more. the excess is let off as heat.

Better would be to monitor the power going through the barrel plug into the laptop as DC.

#54 Post by **bill bolton** » Sun Dec 23, 2007 11:06 pm

blackomegax wrote:The power supply has an effeciency of maybe 50-60%.

Switch mode power supplies, such as incorporated in the ThinkPad power blocks, have efficiencies in excess of 94%, so the wall point number is close enough.

Cheers,

Bill B.

#55 Post by **erik** » Thu Dec 27, 2007 11:15 am

if the ultimate goal is to use a smaller AC adapter then lenovo may be providing a great solution soon with a newly-redesigned 90W AC/DC travel adapter: http://www-307.ibm.com/pc/support/site. ... MIGR-68305

availability is slated for january 8th, 2008. the retail part number is 41N8460 and price is $119.95 USD.

according to this document, accessory tips are available for various cell phones, PDAs, and ipod/iphone.

Power supply - can I use 90 watt with a 65 watt T61

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