I have an acer aspire 7560 that on windows supported (through acer proprietary software) boosting the cpu from 1.9ghz to up to 2.5ghz for long periods of time so long as there was adequate cooling. On ubuntu, I get a top speed of 1.9ghz no matter what I do. I am not trying to overclock past what it is supposed to go, but basically how would I go about doing this? I have googled everywhere and everyone recommends using the bios and that if there isn't an option there it can't be done. I know it can, I know it can be done and still be stable on this computer, and I know that it is possible to do through simple software. My processor is an AMD Fusion A8-3520M quad-core 64 bit processor with integrated radeon graphics and 4gb of ram. Thanks in advance.
Starting with Linux 3.16:
The value for
bapmcan be provided as a module parameter (see here).
The value of
bapmis set to 1 by default for Kaveri, Kabini and desktop Trinity, Richland systems (see here), resulting in Turbo Core being enabled.
Which means that with Kernel 3.16 or later, Turbo Core should work right out of the box with
radeon in many cases.
If you run Debian, or if you run Ubuntu and the above is not true for you, please refer to How to set up a Debian system (focus on 2D or console/server) with an AMD Turbo Core APU for maximum energy and computing efficiency?
I published a detailed analysis over at
unix-stackexchange.com which contains (at least for me) a few surprises. Such as the
ondemand governor potentially being worse than
performance (at least with the Richland A10-6700) and
fglrx apparently using some questionable tricks to improve short-term boosts, abruptly having to compensate for that in the long run. I'm glad I had a closer look at this.
AMD Turbo Core is supposed to be enabled by default in all current Linux versions.
Turbo Core, however, is a feature available on AMD CPUs with and without integrated GPU. And there seem to be two issues regarding those with an integrated GPU. Your A8 falls into this category.
- If the kernel does not have the ATI/AMD 'fglrx' module loaded, the APUs appear to stick to the non-boost/regular frequencies. I presume that the reason is that Turbo Core is a decision made by the APU itself, based on several criteria such as power dissipation/TDP. It seems that the GPU on the chip will not contribute to the decision unless it gets initialised properly. And properly here means that you must use the official dirver; not even the free
radeonwill do the trick. I have filed a bug report over at kernel.org but the question remains whether it will be easy to have the kernel initialise the GPU just for the sake of the boost (if my assumption about the root cause is correct).
- However, even with
fglrx, there appears to be a bug if you intend to use Dynamic Power Management.
For a bit more of explanation e.g. about which tools correctly identify boosts, see here.