Thinkpads Forum

Hi, I should want to know if the 65 W ac adpter i received with my used t61 has the sufficient power to supply it. I have a doubt because i read somewhere of the 90W used with the t61 and the 65w that i have became very hot after an hour of use.
My T61 has a 140 Nvidia GPU (still alive) and i don't know if it's power consumption request a bigger AC supplier. In that case what could be the problem on using a too small supplier?

I was too cautious while using the smaller brick from the x200. It does indeed get alot hotter than the 90V one.
Under Detailed Specifications from Lenovo's support site, it does not list the 65V plug at all.

You should be using a 90W charger with your T61. Excessive use of the 65W will be bad for the 65W charger, and your T61 will have power problems(throttling, slow battery charging), albeit your T61 will still, for the most part, operate safely off the 65W charger just fine. Don't worry about blowing up the charger or damaging your laptop(it won't happen. ), but be sure to get the 90W and use that when you get the chance.

Intel graphics T61s with P-series(lower power) Core 2 Duos can operate safely off the 65W chargers, but the 65W chargers are mostly for the X-series(X60, X61, X200, and their tablet variants) of the same generation. 65W and 90W chargers can be used on any Thinkpad laptop that has the correct plug, but inconsequential depending on the wattage versus the laptop's wattage consumption. For example: 90W chargers can charge X-series tablets surprisingly faster than the 65W charger.

Lenovo was consistently shipping 90W chargers with discrete graphics machines, and 65W chargers with integrated graphics machines. Hence your machine should be using the 90W charger, at least if you want to follow manufacturer specifications.

Ok maybe the adapter could burn out .
For the power consumptions i was also wondering about the tpfancontrol that i'm using under Ubuntu to let the GPU stay at 60 °C (to try to prevent the Nvidia well-known issue) and that is set for an intensive use of the fan (is almost always running at 3200 rpm).
I'm looking for 90 W; it has to be not so expensive..

vm5 wrote:Ok maybe the adapter could burn out

Not likely.

I asked the same question and did some research too.

Seems like some 65w adapters being sold on amazon were being reviewed as burning out way too soon.

I have the same adaptor for an integrated GPU, but I use it also for my ati t60.

If you run sporadic applications, you won't notice the power down, but if you run intensive applications, I would run it with the battery too. I'm assuming with a lack of power from the adapter, it will pull a little power from the battery too.

Just remember the conditions you're putting your charger in.

It's not bad to use a 65W to run a discrete graphics T60 all the time- but if you're using it to run Windows 7 and you consistently watch HD video, or play World of Warcraft, or anything similar, then you may need to consider getting a 90W. It also doesn't help if the charger is crammed between couch cushions, where it'll just get progressively hotter, and if you're charging the battery at the same time.

Only benefit of a 65w over a 95 is the marginally smaller size. Otherwise, if it's plugged to a wall and forgotten, just get a 90w. Then if you do something intensive one of these days you don't have to worry about it. Like desktops, an undersize power supply will work but you'll burn out the power supply if it's constantly being stressed. Fortunately, unlike desktops, a laptop PSU generally don't take any component with it nor give you a good smoke screen when it dies.

The T510 will actually warn you at POST if you use a 65W adapter for it. Still usable, but slower.

I also noticed that a 65W adapter noticeably slowed down the processing power of the R61i. I swapped the CPU some weeks ago, working on the living room table, and afterwards I just plugged in an adapter cord that my wife had used for her Thinkpad earlier in the day. When I updated the Windows experience rating, the CPU only got a score of 3.8, which was less than the previous and slower CPU. I couldn't understand why, but I installed the battery, and it suddenly made it to 5.8. After I was done, and was tidying up, I realized that the adapter I had used was a 65W one. So the battery apparently gave the extra power that the adapter didn't manage to give.

The T6x and X6x actually lock down the CPU speed (usually to 1200MHz max) when using the 65w adapter without a battery attached. The reason is that the 65w adapter cannot supply enough power during some peak usage scenarios-- 35w TDP CPUs can consume up to 50 watts at full utilization.

The battery provides a second power source in this condition, and the "time to complete charging" suddenly increases.