[M4600] if use 90w adapter, how slow the CPU/GPU could be?

I'm considering to buy a spare 90w adapter for better portability, and I know it would slow down the CPU/GPU.

If I only use the laptop for web surfing and netflix, can the underclocked CPU/GPU fair enough to handle these tasks?

 

I am not familiar with the m4600, but technically, most laptop can perform the same as plugin in when on battery.

I would not worry that it will "slow down"

 

An m4600 should pretty easily max that 90watt. Maybe if you have optimus set on the IGP with everything turned off (backlit keyboard, screen turned down, etc) and only doing very basic tasks Im sure you could limp. Granted thats based on the idea that the ac adapter is truly compatible with the system. I honestly dont even think about using the 130watt from my m4400.

 

Depends on your specs...if you have like 2920XM and Quadro 3000 your AC adapter could burn out/explode. But most of the time it gets horribly throttled to the point where there is no point of running on battery.

 

Thanks for the tips.

I tried 180w adapter on M6600 once and both the CPU and GPU are underclocked, so I think 90w on M4600 should have the same issue, but I've no idea how slow it could be, because I did not further test M6600 on web surfing and netflix while 180w attached, which should be a good reference.

As I know, Thinkpad W520 w/ 2920xm and 2000m uses around 20w-25w while web surfing and using netflix, according to Thinkvantage Power Manager. So the 90w adapter fits it well though throttling is inevitable, but not affects much.

For M4600, I've no idea how much the throttling could be, and how much power it drains (I guess it's 40w for i7-2820QM and M5950, because my 6 cell battery could last about 1:40 hours).

 

Do you remember what clocks for GPU and CPU were on 180W PSU?
During Idle? stress?

 

I did not test the exact frequency, but by running superpi and wprime, I'd say it's quite slow, maybe 30s+ to run 1m superpi as far as I can tell

 

I do not know about 90W adapter.

I tried with 130W adapter last year. The laptop is running at lowest state, CPU 800Mhz, GPU 100/150Mhz. I feel it run slower than battery with maximum battery life option.

The battery does not charge with 130W adapter while the laptop is running; not sure if it will during shutdown.

 

I can confirm that. With the 130W adapter the M4600 sits at 800Mhz and doesn't want to budge. I'm in Linux and I normally am able to force different CPU speeds up to 2.5GHz but when this AC adapter is plugged in I'm stuck at 800Mhz no matter what, and despite that the battery is charging very slowly as well. Unplug it and it can go full power on battery.

Strangely enough, at boot time the BIOS says it can't recognize the AC adapter (genuine Dell adapter). It's possible that it assumes the worst and throttles down the entire system just in case.

The GPU runs at 1100Mhz though when it sees it's on AC so it probably does not use the same BIOS settings the CPU throttling does.

 

Thats cute ~~. It run full speed on battery but crap out when plug in a low power adapter?
My understanding was that laptop should be able to run full power no matter what power source as long as you remove the throttle that is set in place.