There are basically two types of laptop coolers. One that blows air up to the laptop and into the vents underneath the laptop. The other type blows downward onto the table and attempts to suck heat away from the laptop. More expensive coolers blows air up into the laptop while it seems less expensive coolers blows air down. Blowing air up is a more effective way to cool a laptop, but it can also blow dust up into the laptop so you need to make sure the table is clean.
The effectiveness basically depends on if the vents underneath the laptop are close enough to the fan(s) in the laptop cooler, plus if there is enough space inside the laptop for air to flow effectively. That will vary from laptop to laptop. So while "Laptop Cooler X" may lower temps in one laptop model by 6C, for another laptop model it may only lower temps by 3C. It all depends on the design of the laptop.
My 15.6" Dell Latitude 3540 does not get too hot when I use it to play games, but nevertheless I decided to order the DEEPCOOL Multi Core X6 yesterday because having lower temps is always better than having higher temps. Currently the i5-4200u maxes out at 73C and the Radeon HD 8850m maxes out at 64C. Not bad at all, but like I said, having lower temps is better. Hopefully the laptop cooler can lower temps by at least 5C. I guess I will fined out next week.
The Deepcool has 4 fans that blows air up to the laptop. All fans can be turned on, or only the bottom two fans can be turned on, or only the top two fans can be turned on.
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