i7-740qm vs i7-640m Battery Life

Hello Guys,



I am debating between

i7-740QM, 16G Ram, FDH Screen, FX 1800M.

Funny HP says 5hours 30min battery life



OR



i7-640M, 16G Ram, FDH Screen, FX 1800M.



My main concern is battery life. I am reading that the i7-Quads do not have an onboard video so it will always be using the power hungry FX1800 and I travel alot.



anyone have either othese laptops can tell me battery life?

Reply 1 : i7-740qm vs i7-640m Battery Life

Quote:

Originally Posted by tilhasbb My main concern is battery life. I am reading that the i7-Quads do not have an onboard video so it will always be using the power hungry FX1800 and I travel alot.

i7-740QM is a Clarksdale cpu built using 45nm tech. It's rated at max 45W TDP.

i7-640M is a Arrandale cpu built using 32nm tech. It's rated at max 35W TDP. It also has an IGP onboard.



The i7-640M should therefore consume less power. Moreso if the system has switchable graphics so can use it's IGP.



If you want a Quad core AND an IGP or switchable graphics then look at Sandy Bridge notebooks.



Consider too a DIY ViDock to add graphics capabilities to systems without such an option. Can be made portable enough to carry around.

Reply 2 : i7-740qm vs i7-640m Battery Life

Quote:

Originally Posted by tilhasbb I am debating between i7-740QM, 16G Ram, FHD Screen, FX 1800M. i7-640M, 16G Ram, FHD Screen, FX 1800M. anyone have either othese laptops can tell me battery life?

The 8540w owners thread has a datapoint. Several different battery configurations are possible (Primary: long-life[3yr, many cycles] 68Wh, standard[1yr, faster charge?] 73Wh. Optional attached external: extended (+52Wh), ultra (+95Wh)). This datapoint is with the 68Wh long-life:

Quote:

Originally Posted by aldoaldo For my 8540w i7 720qm quadro fx1800 Full HD my 8cell 68whr for internet (wifi on) and office and 3/4 brightness lasts about 2h50min.

The 8740w Benchmark thread has some data which may be useful:



1. The 620M comes with a dual-core motherboard, which only has two dimm slots. 16GB RAM is currently significantly more expensive for a two-dimm motherboard (need two 8GB DDR3 dimms) than the quad-core motherboard.

Siorah has gotten an 620M to work in a quad-core motherboard with four dimm slots, though it only recognized 16GB RAM on a 32GB system.

Update on the 32GB

8740 AND 8540 Memory Configurator



2. Siorah has reported similar numbers for the 8740w (not 8540w), after swapping a 620M into a 720QM system.

The times should be low compared to a 8540w system because

- the 8740w has a larger screen

- the 8740w has a Quadro 2800M, not a Quadro 1800M.

- the 8740w with 620M was measured on a quad-core motherboard with 4 dimm slots, not 2.

But shows roughly how much difference it may make.

Code:

8740w battery times summary:



CPU Model:	720QM	620M

CPU TDP watts:	 45w	 35w



Idle minutes:	135min	157min (+22min)

MP3 minutes:	118min	134min (+16min)

DVD minutes:	 98min	111min (+13min)

BD minutes:	 83min	 92min (+ 9min)

Collected 8740w Owners Benchmarks Data: Battery Times

Reply 3 : i7-740qm vs i7-640m Battery Life

Also, I don't think the 8540w can use the IGP.

Reply 4 : i7-740qm vs i7-640m Battery Life

Thanks everyone!



I know the processor QuadCore uses 10Watts more but what concerns me more is the videocard power draw. If the Dualcore can disable the nvidia videocard which uses 45Watts on it's own.



So surfing the net the Dual core would use 10+45 = 55Watts Less than the Quad.



Is that true? if so the battery life difference should be significant.

Reply 5 : i7-740qm vs i7-640m Battery Life

Quote:

Originally Posted by tilhasbb If the Dualcore can disable the nvidia videocard which uses 45Watts on it's own.

Will you be using 3D while on battery? If not, consumption will be less. If you plan to mostly use battery to read email or text without video/animations, notice that the Quadro 1800M only uses 3.8w when idle (PowerMizer, EnergyStar).



The 1800M does not support Optimus.

NVIDIA Quadro Mobile Solutions

No Optimus means that in order to use both the 1800M and the IGP, the notebook manufacturer would have to provide a switch on the motherboard so that either the 1800M output or the IGP output could be wired to the internal screen.



I believe the 8540w only wires the 1800M to the screen, not the IGP.



(As I understand, for notebook+GPU combinations that support Optimus or equivalent graphics switching, the GPU result memory image is copied back to the IGP memory, and only the IGP output is wired to the screen. That additional copying also uses more power, so Optimus might be less efficient if you frequently use 3D while on battery.)

Reply 6 : i7-740qm vs i7-640m Battery Life

I didn't know that about the GPU.



HP EliteBook 8540w Mobile Workstation (ENERGY STAR) (XT970UA) specifications - HP Products and Services Products

I'm leaning towards this model now.



i7-740QM Processor (1.73 GHz, 6 MB L3 cache)

8 GB 1333 MHz DDR3 SDRAM (I'll add another 2 DIMMs of 8G for a total of 16G)

320 GB 7200 rpm SATA II

DVD+/-RW SuperMulti DL LightScribe

15.6" diagonal LED-backlit FHD anti-glare (1920 x 1080)

NVIDIA Quadro FX 1800M graphics with 1 GB dedicated GDDR5 video memory





I currently have a

i7-620M

Nvidia Quadro 880M

8G Ram

256GB 7200 RPM HD

DVD+/-RW SuperMulti DL LightScribe

15.6" diagonal LED-backlit FHD anti-glare (1920 x 1080)



and I about 2hours and 30minutes of battery life on it.



I'm hope to keep atleast 2+hours with the Quad core..

Reply 7 : i7-740qm vs i7-640m Battery Life

Anyone here with a Quadcore?

Can you please run Osiris Development - BatteryBar, the most accurate battery meter for Windows

it's a neat free app which tells you how much power your using.



With 1/2 screen on my 640m I get discharge rate of -17,438mw which gives me a little over 3hours

Reply 8 : i7-740qm vs i7-640m Battery Life

I will use that program

Reply 9 : i7-740qm vs i7-640m Battery Life

Anybody at home? I installed that Battery Bar however I do not see where I can find information about how much power I use.