65W or 90W power supply for dual-core i7 on T530 ?

[lleblanc]

With the Lenovo configuration wizard for the T530, if I upgrade the CPU from an i3 to an i5, then to a dual-core (3520) i7, i can choose between a 65W and a 90W power supply.

If I then change to a quad-core i7 (3720), the wizard restricts the choice to a 135W brick I badly want to avoid. Returning to a dual-core i7, the wizard now only offers a 90W cord. Sounds like a bug. But is 65W enough for that CPU? Why would I go to 90W? (my T41 sports a small 72W

Other power-related (?) options I had selected when changing CPU were:

15.6" FHD (1920 x 1080) LED Backlit AntiGlare Display, Mobile Broadband Ready
NVIDIA NVS 5400M Graphics with Optimus Technology, 1GB DDR3 Memory
8 GB DDR3 - 1600MHz (2 DIMM)
Keyboard Backlit - French Acnor
UltraNav with Fingerprint Reader for Color Sensor, Smart Card Reader
720p HD Camera with Microphone
500GB Hard Disk Drive, 7200rpm
16GB mSATA Solid State Cache Drive
DVD Recordable
Express Card Slot & 4-in-1 Card Reader & Smart Card Reader
6 Cell Li-Ion TWL 70+
Bluetooth 4.0 with Antenna
Intel Centrino Ultimate-N 6300 AGN

[TTY]

Hello,
the 65 W adapter is sufficient for the dual core i7, but as soon as you select a quad core i7, the configurator also includes the nVIDIA Optimus graphics. And as soon as the notebook is configured with discrete graphics, i.e. nVIDIA Optimus, you need a 90 W adapter at least, and 135 W if you select a quad core i7. 65 W adapters are only available for configurations that have the Intel 4000 graphics and dual core processors.

[deltoid84]

Hi,
When I received my T430 i7 with nVidia Optimus card, it came with 90W power supply. I have already used my laptop with my "old" 65W power supply from my X201 and it works fine. The only thing I've noticed is that 65W power supply does not charge battery as quickly as 90W one.