Hi Nico,
> On 01.05.2016 12:26, Daniel Kulesz via coreboot wrote:
> > Coreboot with idle=poll: 15,8W
> > Coreboot running "stress": 37,2W
> well, this is what I would expect from the specs.
>
> > Vendor BIOS with idle=poll: 15W
> > Vendor BIOS with intel_pstate=disabled: 10W
> > Vendor BIOS running "stress": 24,3W (!!)
> This looks suspicious. Doing some calculation:
> You are measuring at the wall plug, efficiency could be around 83%,
> which would leave 20W. Chipset, backlight and other stuff needs power as
> well, say around 8W, leaving 12W for your 25W TDP CPU???
>
Well, I could imagine that the PSU's efficiency is better than 83%, and maybe
the CPU is just rated at 25W TDP while in fact it consumes less. Please note
that the whole family of CPUs is rated at this wattage and so is the P9600
which runs at 2,66GHz and not just 2,53GHz and at a slightly higher min.
voltage (but slightly lower max. voltage).
> So, before bothering yourself with the power consumption difference
> under load, I would also check the performance of coreboot vs. vendor
> BIOS.
>
That's a good point and I was also thinking about this. So I just did a few
measurements using "cryptsetup benchmark" (results attached). As you can see,
indeed performance with the vendor BIOS is significantly lower. But why?
As I don't really need so much performance and rather would prefer better
battery lifetime, the vendor BIOS' behavior would suit me better. I will try to
tweak its settings a bit and see how this impacts performance and power
consumption so we can get a better idea what could be causing the impact.
> > And I didn't find any documentation about how to actually extract the
> > VGA Bios part, so any hints are welcome.
> Um, if you find a way, please document ;)
>
As I posted, it is there, but a bit hidden in the Wiki.
I also ran a test series with the microcode updates included => no difference.
Cheers, Daniel
# Tests are approximate using memory only (no storage IO).
PBKDF2-sha1 409600 iterations per second
PBKDF2-sha256 264258 iterations per second
PBKDF2-sha512 190511 iterations per second
PBKDF2-ripemd160 273066 iterations per second
PBKDF2-whirlpool 83591 iterations per second
# Algorithm | Key | Encryption | Decryption
aes-cbc 128b 95.1 MiB/s 98.3 MiB/s
serpent-cbc 128b 32.8 MiB/s 123.5 MiB/s
twofish-cbc 128b 82.6 MiB/s 108.7 MiB/s
aes-cbc 256b 72.7 MiB/s 74.4 MiB/s
serpent-cbc 256b 32.8 MiB/s 123.4 MiB/s
twofish-cbc 256b 82.6 MiB/s 108.7 MiB/s
aes-xts 256b 98.0 MiB/s 97.9 MiB/s
serpent-xts 256b 111.9 MiB/s 115.9 MiB/s
twofish-xts 256b 100.3 MiB/s 101.1 MiB/s
aes-xts 512b 74.0 MiB/s 73.8 MiB/s
serpent-xts 512b 112.1 MiB/s 115.9 MiB/s
twofish-xts 512b 100.2 MiB/s 101.0 MiB/s
# Tests are approximate using memory only (no storage IO).
PBKDF2-sha1 665340 iterations per second
PBKDF2-sha256 420102 iterations per second
PBKDF2-sha512 303407 iterations per second
PBKDF2-ripemd160 428339 iterations per second
PBKDF2-whirlpool 132129 iterations per second
# Algorithm | Key | Encryption | Decryption
aes-cbc 128b 131.5 MiB/s 155.5 MiB/s
serpent-cbc 128b 51.5 MiB/s 195.2 MiB/s
twofish-cbc 128b 130.7 MiB/s 171.6 MiB/s
aes-cbc 256b 104.1 MiB/s 117.5 MiB/s
serpent-cbc 256b 51.5 MiB/s 195.2 MiB/s
twofish-cbc 256b 130.7 MiB/s 171.6 MiB/s
aes-xts 256b 155.0 MiB/s 154.8 MiB/s
serpent-xts 256b 176.1 MiB/s 182.3 MiB/s
twofish-xts 256b 158.7 MiB/s 159.7 MiB/s
aes-xts 512b 116.9 MiB/s 116.5 MiB/s
serpent-xts 512b 176.1 MiB/s 182.3 MiB/s
twofish-xts 512b 158.7 MiB/s 159.5 MiB/s
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