Dell Latitude E6540 OR Precision M4800 ..........!

I added my vote to the poll. My money is on Precision. If you can deal with the higher price and higher weight, I would pick it over the Latitude every time.

Also, do a clean install, and follow the Dell guide:
http://www.dell.com/support/home/us...t/product/precision-m4800-workstation/drivers
http://downloads.dell.com/Manuals/all-products/esuprt_laptop/esuprt_precision_mobile/precision-m4800-workstation_White Papers_en-us.pdf

Treat your tools well and your tools will treat you well.

 

As I understand it, E6540 have cooling problems. Cheapening the design over generations, possibly.
Ankupan, as it appears, needs to work in a hot climate without AC.

To which I have to add that—now when the temp in my room has reached about 31 °C (88 °F)—it is no longer easy or truly possible to keep my M4800 fully mute under even modest workloads. The machine works alright—as one would rightfully expect—but the fans do hum quietly most of the time.

So, Ankupan, if you’re looking for a computer to work in something like 40+ degrees Celsius, as you have stated, do not expect it to not run its fans, which shall also reduce the typical battery life.

(BTW, the officially stated operating range for both the computer and its AC adapter is 0–40 °C; only the battery is OK with up to 70 °C while discharging; 50 °C when being charged.)