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NeddySeagoon
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Joined: 05 Jul 2003
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Location: 56N 3W
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 Posted: Sun Sep 25, 2016 3:48 pm Post subject: |
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Zucca,
The SD card is a 4 bit bus, clocked at 50MHz, that gets you a theoretical maximum 25Mb/sec transfer rate.
16.84MB/sec is impressive though, compared to my 5MB/sec.
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NeddySeagoon
Computer users fall into two groups:-
those that do backups
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Zucca
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Joined: 14 Jun 2007
Posts: 3945
Location: Rasi, Finland
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| Posted: Sun Sep 25, 2016 4:10 pm Post subject: |
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Hm. But can you possibly change how the bus operates so that it could increase it performance? | Yamakuzure wrote: | Switching from dtoverlay=mmc to dtoverlay=sdhost in /boot/config.txt did wonders!
While emerging something I can now switch to another console and the keyboard works without delay. It was impossible to do anything with the MMC SDHCI driver. |
... and I even read people applying some overcloking of the bus (which I'm not very much keen into):.
But my main question here is what does that 'dtoverlay=sdhost' -option actually do? Speed increase? And should I activate it?
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..: Zucca :..
| My gentoo installs: | init=/sbin/openrc-init
-systemd -logind -elogind seatd |
| Quote: | | I am NaN! I am a man! |
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NeddySeagoon
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Joined: 05 Jul 2003
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| Posted: Sun Sep 25, 2016 5:31 pm Post subject: |
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Zucca,
There are two drivers in the kernel for SD Cards.
mmc and sdhost.
Choose one or the other. You need to use sdhost for WiFi as its on the SDIO bus.
The overclock_50=63 part of that command says to run the SDIO interface at 63MHz, when a clock speed of 50 MHz is called for.
Good old overclocking :)
sdhost will be the name of a file in /boot/overlays.
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NeddySeagoon
Computer users fall into two groups:-
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axl
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Joined: 11 Oct 2002
Posts: 1146
Location: Romania
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| Posted: Mon Sep 26, 2016 1:12 am Post subject: |
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entirely my mistake. i thought of raspberry pi's in general.
it's a good thing to find out you can get that type of performance from pi3. |
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evoweiss
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Joined: 07 Sep 2003
Posts: 1678
Location: Edinburgh, UK
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| Posted: Sat May 05, 2018 1:33 pm Post subject: |
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Hi there,
I'm going to be migrating my home desktop to a Raspberry Pi 3 that I purchased just recently. I could use Raspbian, but I'd rather keep a Gentoo system for various reasons.
I'm going to keep the hard drive from my old computer as an external USB drive (it'll be in a powered case). Would it be possible to keep /usr/portage on that drive and to do all the emerging, etc. on that drive?
Best,
Alex |
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NeddySeagoon
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| Posted: Sat May 05, 2018 1:54 pm Post subject: |
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evoweiss,
In a word. Yes. Just put /boot on the SD card.
| Code: | Pi3_arm64 ~ # df -h
Filesystem Size Used Avail Use% Mounted on
/dev/root 24G 2.2G 21G 10% /
devtmpfs 10M 0 10M 0% /dev
tmpfs 97M 368K 97M 1% /run
tmpfs 485M 0 485M 0% /dev/shm
cgroup_root 10M 0 10M 0% /sys/fs/cgroup
/dev/mapper/Pi3_64-buildspace 20G 4.6G 15G 25% /var/tmp/portage
/dev/mapper/Pi3_64-portage 3.0G 797M 2.1G 28% /usr/portage
/dev/mapper/Pi3_64-distfiles 40G 13G 25G 35% /var/cache/distfiles
/dev/mapper/Pi3_64-home 49G 33G 14G 72% /home
/dev/mapper/Pi3_64-packages 40G 12G 26G 32% /packages
/dev/mapper/Pi3_64-src 20G 12G 6.8G 64% /usr/src
/dev/mapper/Pi3_64-tmp 4.0G 16M 3.8G 1% /tmp
/dev/mmcblk0p1 8.0G 288M 7.8G 4% /boot |
If your Pi is a 3B+ it can boot from USB out of the box. Older Pi 3Bs need a one time irreversible change.
No SD card required.
Building on the Pi is painful. Not everything will build in 1G RAM and the bigger packages that do take a long time.
The least worst approach is cross distcc.
You don't say if you will do a 64 bit or 32 bit install.
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NeddySeagoon
Computer users fall into two groups:-
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Gentoo on ARM
