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Thank you for contacting the Intel community.
I was able to find the Intel® Core™ i3-6100T Processor but I could not find the Intel® Core™ i5-6400U Processor, it looks that this a tray processor and the information is available only at your computer manufacturer, I found this processor but without the letter U at the end, usually the letter U means Ultra Low Power, the letter T also consumes low power, however, the systems configurations performance not depends only on the processor it depends also on the whole system configuration and how all the components interact with each other.
At this point for better information about these two systems it will be better for you if you contact these systems manufacturer as they are more familiar with these computers.
You should be able to get support here:
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