M6600 Owners Thread

It is always operating at 100-240 volts depending on your country.

It does not always pull 210-240 watts.

I have done extensive testing with a Kill-A-Watt digital power meter. Right now as I type this, my M6600 is pulling between 66 and 74 watts in the High Performance power mode. This is docked with the onboard screen closed and off. I only have office applications running.

Now I have fired up Prime95 and fully loaded all 4 cores. Since the M6600 will let the 2920XM CPU pull 62.5 watts in turbo mode (54.5 on a non XM quad core) if nothing else is running, I see that on the Kill-A-Watt I am now pulling 130 watts from the wall.

Now, before we go further, lets remember how watts from the wall differs from watts to the computer. Watts are a unit of work. The power supply will supply the computer with 210 or 240 watts (10.8 amps) of power at 19.5 volts. The power supply draws AC power from the wall at up to 3.2 amps at 100-240 volts depending on your country. Since I use 120 volts, those 3.2 amps convert to 384 watts. When I convert 10.8 amps at 19.5 volts to watts, I get 210.60watts that can be delivered from the 210 watt adapter. The 240 watt adapter is rated to output 12.3 amps or 239.85 watts into 19.5 volts.

The conversion from 120V AC to 19.5 DC is roughly 90% efficient. When you are pulling 150 watts from the wall, 15 watts of heat is produced during the conversion. This is why the power supplies are so large - they have to radiate that heat away so that the adapter stays cool. Since the power supply has no fan, it has to rely on surface area. Efficiency actually varies depending on the load presented to the power supply, but for simplicity I am assuming 90% for all loads.

So, getting back to those measurements. With Prime95 going and the CPU running at 62.5 watts, I am pulling 130 watts from the wall. If we subtract out the heat lost in the power conversion. The machine is pulling approximately 117 watts from the power supply.

When I run a Direct X 11 game that puts a load on the GPU and some on the CPU, I am pulling 175 watts from the wall and 157.5 watts from the adapter.

I don't currently have Furmark installed, but in previous testing I would get into the 190 watt range when I ran Furmark and Prime95 with the Quadro 4000M. I may have hit 200 watts, but I don't remember for sure. The machine never throttled the CPU, but it did pull it out of constant turbo mode so it ran at 2.5ghz instead of 2.8-3.2ghz. Also, remember that the 45 or 55 watt power envelope of the processor includes the power produced by the CPU and GPU. If you had the onboard GPU using its 10-12 watts, there is less room for the CPU to stay in turbo mode. When the Nvidia or AMD video card is running, the on chip GPU pulls 0.046 watts.

Looking at that 190 watts from the wall number, you might wonder how the machine is running. So, 190 watts, minus 19 for heat losses in the adapter gives us 171 watts in use. We know the Nvidia GPU can use up to 100 watts and the AMD up to 75. The system board and hard drives use about 8 watts. The display uses 12 watts. The CPU will use up to 45 for a QM and 55 for an XM. With everything maxed and in a worst case scenario, the machine will want 175 watts. So why did I only pull 171? Because the XM processor came out of turbo mode with Furmark also running. Since the on chip GPU was not running, the XM processor was only pulling 45-50 watts instead of 55. So, no throttling, but then again, less turbo mode. Remember, this is all synthetic testing. I consider it cheating since you will never see this in the real world.

On the other hand, if you have Optimus enabled, you can get the draw from the wall below 25 watts. No kidding. Less than 25 watts.

 

I must have not explained myself correctly in my brief responses. I know the formulas, wattage vs amps, the voltage differences, and the loads produced on the AC side of the PSU. At any rate, Bokeh's detailed answer explains it better so I will leave it at that.

Scott

 

Hey, what's the first thing I should check if my slot load cd/dvd player lights up at startup, but doesn't "grab" the cd or seem to be reckonized in the My computer?

 

Device Manager from
1. My Computers
2. Control Panel

The CD can be faulty if your drive is detected in Device Manager. Try another disc.

 

couldn't find the CD player in Device Manager. Meant to say that.

 

thanks sargent 75. I think I got it figured now.

 

Firstly I'd like to say hello for everybody. This in my second post on this forum but I'm reading this thread for a long time. I'm the owner of M6600 with i7-2720QM and ATI M8900.

Bokeh thanks a lot for Your explanation about Power consumption in M6600 - it's really a big portion of knowledge. BTW. I've read also your review of this machine-very good work, in my opinion.

Yes You can see this in real world...

Please do the same test (Prime+furemark or 3d mark11) but with battery at level below 90%. Then You will need extra current (~40 Watt) from PSU to charge battery (express charge in BIOS). In my config that situation cause cutting Ati Clocks from nominal 680/900Mhz to 400/900Mhz. But CPU stays 'rock' - no changes in clocks.

Above 90% level battery is charged with less current: ~5-10Watt. Then Ati backs to its nominal 680/900Mhz. I observed clocks with HWinfo.

Now real world: I go to work without PSU (forgot)-working on battery only...After that I go back to home, connect M6600 to supply to charge battery and looking for some relax with Battlefiled 3. I notice big drops of FPS during playing! I have to wait until battery level is above 90%-then gameplay is much better.

Could anybody else with Ati card do this test: Battery below 90%+ charging+3Dmark11? what is score? Do you notice the same drops in performance? Mine is 2200P vs 3200P (battery Not charged vs battery charged above 90%).

Maybe newer Bios will help a little (mine is A03), but I don't really think so...My opinion is that these Ati core lower settings are applied to Bios of M6600 to avoid overload and overheating PSU during charging battery. Simply - Power Management hidden in Bios. And we can do nothing.

P.S. Sorry for my english-it's not my native language.

Regards, katmai7.

 

Does this mean that if I turn on Optimus, I can use my original PSU on an airplane?

I apologize for not knowing this, but how do I turn that on?
I'm assuming it is a BIOS option?

 

Optimus will make the machine draw much less power, but the big thing is making sure your battery is fully charged. You could also remove your battery, which would work as well, but there is a risk that if the power demand went up, then the machine without a battery would simply turn off if the AC plug tripped.

The other thing is to make sure you are running the Dell "Extended Battery Life" power plan in Windows 7.

If you have Optimus, enabled, you would probably never use more than 40 watts unless you were gaming or rendering video.

If you knew the outlet was 100 watts, you could also get a Latitude D or E series 90 watt power adapter and use it on the plane.

By the way, you must have REALLY good seats or be in the exit row. The M6600 is not always usable in coach because of the screen height. Its better than the M6500 was, but still kinda big.

 

What I have seen is that - at any battery charge level - the M6600 simply quits charging the battery when you are hammering it with a heavy load. Update your bios

Also, your English is great.