CPU stay at 1190 MHz at Nexus 5?

[ckgbr]

I have notice a very strange fact playing with Tekken 6 with Nexus5 (frameskip auto).
At start, I got a full speed about 15/60 (95%) and after 2 rounds, it decreases to 8/60 (68%)... And when I check CPU, it is lock at 1190 MHz, not 2265 Mhz at start.
I have try to use setcpu to lock the CPU perfomance (2265 Mhz min and MAx and governor perfomance) but it doesn´t work.
And I only notice this perfomance down at Tekken6, I usualy play Dragon Ball Tag tournament, Naruto Shippuden ultimate ninja impact, PES 2013 and they are great, and it runs 100% without frameskip.
Thanks a lot and this is a best emulador ever....

PS: I´m always using the last version of automated builds.