Laptop overclocking for fun

[DreadKnight]

Alright I know overclocking a laptop is futile for performance gains. I have a desktop for heavy workloads. This is purely for fun.

The laptop in question is a Lenovo thinkpad t440 with an i5 4300U, 8GB ram, and intel HD 4400. 

I've been using XTU to tune things as throttle stop is confusing for now. It is a locked processor so no multiplier changes. However when running stress tests and benchmarks I see the chip is power limit throttling. Is there a way to change the package TDP or am I just gonna have to undervolt? Also what is a good cpu stress test and benchmark? I've had success with increasing XTU benchmark scores with undervolting. 

Edit: so now I've learned how to undervolt with ThrottleStop. But when running stress tests I'll see the package TDP go to 22w for the first minute or so then the power limit kicks in to slow things back down to achieve 15w. why does this happen and how can I let it run turbo longer?

[Jurrunio]

Undervolt is your only option. You can try raise turbo boost max but usually that doesnt work

[DreadKnight]

So I've noticed something odd. When I start Prime95 or the XTU benchmark it starts with the package TDP at 18w then about half way through it power limit throttles down to 15watts dropping ~400MHz. So this shows it's capable of going over the 15w TDP at least temporarily. How do I increase the time it stays over 15w. thermals still have headroom with the fans barely spinning and temps up to 67 celsius. Are there any guides you people would recommend for learning throttlestop?