Re: [coreboot] Lenovo X200 running Coreboot drains 3-4W more power than with Vendor BIOS

[Daniel Kulesz]

On Sat, 7 May 2016 15:53:47 +0200
Zoran Stojsavljevic  wrote:
> > @Zoran: I also have an X220 (2nd gen Core I5) on which I did not
>
> undertake any Coreboot experiments yet. But I
> > suppose you are rather asking for much newer CPUs from the 6th and 7th
>
> generation?
> > Cheers, Daniel
>
> Hello Daniel,
>
> Second generation CORE is SNB. CPUID something like 0x20xyz. CORE 2nd gen.
> was released Y2011.
> Third generation CORE is IVB. CPUID something like 0x30xyz. Core 3rd gen.
> was released Y2012.
>
> What I am talking/pointing ot about is the following:
> *Fourth generation CORE is HSW. CPUID something like 0x40651 (i5 4300U) -
> HP 840 G1 - one of my laptops. Released Y2013.*
> *Sixth generation CORE is SKL. CPUID something like 0x606E3 (i5 6200U) - HP
> 450 G3 - another of my laptops. Released Y2015.*
>
> 4th (HSW-U) and 6th (SKL-U) generations of CPUs in laptops: these are ones
> I am talking about/pointing to (don't think CORE 5th gen. is important).
>
> Sorry I am late with Re:.

Hi Zoran,

You are welcome! But I don't have any of these newer laptops and afaik Coreboot does not support many of them, either. Especially the newer Thinkpads (T/X240+) are not supported. But sure, if anybody has one of these machines doing similar experiments would really make sense. I still wonder why I didn't read or hear about any complaints about running Libreboot/Coreboot on a X200 since the difference of the missing C4 mode (by default at least) is so striking.

Cheers, Daniel

Lenovo X200 running Coreboot drains 3-4W more power than with Vendor BIOS

[Peter Stuge]

Daniel Kulesz via coreboot wrote:
> my X60 supports C4 although it also seems to consume way too much power.

That platform has at least one significant power saving issue open,
which I think is no longer too well understood by the active folks.
It also involves power saving states, but I don't know exactly what
it is.

Daniel Kulesz via coreboot wrote:
> I .. wonder why I didn't read or hear about any complaints about
> running Libreboot/Coreboot on a X200

I guess that anyone who retrofits open source firmware feels that
the advantages outweigh such problems.

The X60 runs much hotter with coreboot than with vendor BIOS. Some of
that can probably be attributed to coreboot being worse at power
saving, but there are still differences under full load. I would not
be at all surprised if one reason is that the vendor BIOS
aritificially restricts the performance in order to meet thermal
design requirements.

In other words: I can very easily imagine that robust operation and
good-looking mechanical design was more important for the vendor than
getting top performance out of CPU+chipset and that they implemented
this policy in the BIOS, but coreboot doesn't, because noone in
coreboot knows what the appropriate thresholds are.

This is an intrinsic problem for anything that is retrofitted.

//Peter