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Pi help for a newbie - Unicorn99 - 2014-02-20

Hello all.

I have just purchased my Rasberry PI.
It is running Openelec 3.4.2
I have a class 10 memory card.

My question is how to speed up going in and out of my video add ons.

I have changed my skin to Amber and noticed a difference in the UI.

I have read (on these forums) about transferring system files onto USB to improve speed.
Would this make a significance difference?

I have got an external USB 3.0 1.5 tb hard drive lying around.
I know a partition would be required for system files and then my own storage.

Is there any step by step guides to this ?
I have seen a few guides which talk about altering coding. I.m happy to do this but not sure how to do it.

Can any one help ?

RE: Pi help for a newbie - apeg - 2014-02-20

Hi Unicorn99,

your 1.5tb hard drive is not going to do the trick for USB operating system offload. If you want to explore that option you need to get yourself a decent 2GB+ usb 3 key. they are pretty cheap if you shop around, look into Raspbmc. its a nice little pre-packaged openelec bundle that has a very simple USB key offload install just as your looking for.

You can then use your 1.5tb to store content?

If you will get faster speeds from the USB key OS offload, its debatable. Some people swear upon it, i have a class 10 card and noticed a little difference but nothing crazy.

One of the main advantages of USB offload is you can crank up the over clock settings and don't have to worry about corrupting the SD card (Pi's seem to do that when you push them too hard)

RE: Pi help for a newbie - Unicorn99 - 2014-02-20

Thanks for the reply and info.

I will buy the USB stick. What does "3 key" mean?

Forgive my ignorance, do you know of any guidance to install Raspbmc or is it just a case of putting the required files onto the USB ?

So I take it I would over clock on the USB ?

RE: Pi help for a newbie - DBMandrake - 2014-02-20

There are some things you can do to speed up XBMC on the Raspberry Pi, but you have to accept the fundamental fact that although GUI performance is now pretty good in recent versions of XBMC for the Pi in terms of scrolling, screen refresh and so on, (and that video playback is excellent - I just did a test today where the Pi could play 70Mbps 1080p H.264 without any frame drops!) that anything that takes raw processing power will always be slow on a Pi.

In particular, searching for listings in certain add-ons can be slow. Typically you will have a 2-3 second delay between selecting an item in a list and the next list coming up, and anything that is building a list of movies etc from data online such as a search could take 5, 10, 20 seconds or more while a PC might do it in 1-5 seconds.

Having said that there is quite a bit you can do to speed things up. Personally I found one of the biggest improvements was to start using the new F2FS filesystem instead of ext4. As far as I know, Raspbmc is the only distribution offering this, so while I know you're using OpenElec, you might want to give Raspbmc a try. http://www.raspbmc.com/ Raspbmc can now use F2FS on both SD card installs and USB installs. (bear in mind most other OS's cannot read F2FS formatted disks)

Overclocking is of course essential for obtaining best performance - every Pi has a different overclock limit beyond which it becomes unstable, my Pi (with Samsung memory) can run 100% stable on "Super" over clock in Raspbmc which is 950 cpu, 450 core, 253 gpu, 450 sdram, and 6 overvolt. On Raspbian I can run it on High overclock (950 cpu, 250 core, 450 sdram, 6 overvolt) but it can't even finish booting on Turbo (1000 cpu, 500 core, 600 sdram, 6 overvolt)

By the way, you'll read a lot about SD card corruption when over-clocking with people suggesting to use a USB install if you over-clock - this is no longer necessary as of the firmware released in December. The current version of Raspbmc contains the fixed firmware so over-clock related SD corruption seems to be a thing of the past. I'm not sure if the current OpenElec contains it but I would imagine so.

The next thing is to use a lightweight skin - you're already using Amber and that's probably the most light weight but still good looking skin, so stick with that.

A USB install can speed things up, but only if your USB drive is faster than your SD card - and that's not always the case! Some cheap USB drives are very slow (particularly write speed) so it's best to do a speed test of both SD card and USB drive before deciding which to use. See here for details:

http://www.raspberrypi.org/phpBB3/viewtopic.php?f=26&t=31925

Raspbmc has a check box in the installer which you can use to very easily do a USB install if you decide to go that way - it does all the partitioning of the USB drive for you.

If you're currently using a wireless connection it might be worth trying an Ethernet connection if at all possible for best performance.

Another thing that can speed up the GUI (ironically) is to enable 1080p GUI mode - by default XBMC on the Raspberry Pi only runs the GUI at 720p and scales it up. (Video plays at native res however) For some reason this seems to cause GUI animation to stutter and I find the GUI actually runs more fluidly if I enable 1080 mode for the GUI. In Raspbmc this is accomplished in the raspbmc settings addon by choosing "Remove UI res limit". I don't think there is any way to do this in OpenElec currently.

Hopefully that helps. Personally I'm quite happy with the performance of XBMC on my Pi - video playback itself is flawless even at 1080p output with high bitrate files, I can use the TV remote to control it, the basic GUI navigation speed is fast enough and fairly smooth (at least on Amber) the only real issue is that response times navigating add-ons is a bit slow, but I accept slightly slower navigation to content for the convenience of having an inexpensive, tiny, silent, very low power consumption box attached to the TV instead of a big noisy home theatre PC.

It has also been extremely stable for me - far more so than XBMC running on Mac OS in another room which crashes on me fairly regularly...the Pi is left on 24/7 and has only crashed on me 3 or 4 times in several months, and all of those "crashes" have been XBMC, not the underlying OS or the hardware, and I've had no file system corruption at Super over-clock on an SD card install.

RE: Pi help for a newbie - apeg - 2014-02-20

USB3 key... its just the next generation of USB devices. Some USB2 keys tend to have speeds that's are so low you wont see any advantage.

this one will do the job and boasts speeds WAY faster than the Pi could handle:
http://www.newegg.com/Product/Product.aspx?Item=N82E16820220610

the USB operating system offload still requires the SD card, its used minimally (for bios requirements i think).

1. download Raspmbc
2. copy the image to your SD card
3. put the SD card and the USB3 key into your Pi and power it up
4. nice simple gui will guide you through the install process where you choose if you want a SD only install or and SD/USB key install... trust me very simple

look up Raspmbc, there are loads of tutorials out there.

RE: Pi help for a newbie - Unicorn99 - 2014-02-20

That's great info Guys thanks. When installing raspmbc, i take it all my existing addions will go ?

What i didn't understand but now do is that raspmbc and Openelec are like different operating systems.
I'm currently using a KINGSTON Ultra 8GB Class 10 SD Card.
Any idea how much I could over lock this to safely ?

RE: Pi help for a newbie - apeg - 2014-02-20

you're doing a fresh install of Openelec when installing Raspmbc, so yes your current add-ons will go. but there are a few add-ons that are bundled with it

Over clocking:
Every Pi seems to be a little different, some i cant push past 900mhz, while another unit runs perfectly at 1ghz. id say start @ 850 and slowly work your way up. but keep in mind your power supply also plays a big part with over clocking success. i use 5v 2000ma with great success, but ive read people having greater success with 5.1,5.2v units.

If you are going to push your Pi to 1ghz you will probably need an open case, one with the sides open. I find the closed cases tend to cause heat problems.
example closed case = http://www.ebay.ca/itm/RASPBERRY-PI-TRANSPARENT-ACRYLIC-CASE-ENCLOSURE-COMPUTER-BOX-/321186871544?pt=US_Computer_Cases&hash=item4ac83ab8f8&_uhb=1
example open case = http://www.ebay.ca/itm/Clear-Raspberry-PI-case-half-open-frame-enclosure-Free-Heatsink-1pcs-/151225985178?pt=US_Computer_Cases&hash=item2335c5689a&_uhb=1

FYI the example open case is the best case on the market for the Pi, the bottom mounting screws keep it secure while the no sides keep good air flow.

RE: Pi help for a newbie - DBMandrake - 2014-02-20

(2014-02-20, 17:41)Unicorn99 Wrote: That's great info Guys thanks. When installing raspmbc, i take it all my existing addions will go ?
Yes, if you install raspbmc the SD card will be wiped and you'll lose your existing config. There is a way to back up your xbmc config but if you haven't done much configuration you're probably best to start over.

Also consider buying a second SD card at some point so you can have one for your "real" install, and another card to experiment with - then when you're done experimenting just swap the cards back over. I have three cards for my Pi - one dedicated to XBMC running raspbmc, one that has Raspbian and other OS's installed, and a 3rd scratch card I use to experiment with images I download etc.
Quote:What i didn't understand but now do is that raspmbc and Openelec are like different operating systems.
Well they're more akin to different linux distributions.

Both are stripped down, optimised versions of Linux with the XBMC app bundled and pre-configured for you. But they're different projects maintained by different people.

Quote:I'm currently using a KINGSTON Ultra 8GB Class 10 SD Card.
Any idea how much I could over lock this to safely ?
Finding how high you can go on overclock is a matter of trial and error. I'd start with "Fast" over-clock on Raspbmc, when you're happy that things are working well try the Super over-clock setting, if it still runs reliably stick with that, if you start getting crashes go back to Fast.

RE: Pi help for a newbie - Unicorn99 - 2014-02-20

Before changing to raspbmc think I'm going to try over clocking my sd card on Openelec.

My power supply is 5v 1.5A 1,500ma.

For example, if I over clock to 850 and it becomes unstable, will it just be a case of reverting it back with no further issues ?

RE: Pi help for a newbie - DBMandrake - 2014-02-20

(2014-02-20, 18:08)apeg Wrote: Over clocking:
Every Pi seems to be a little different, some i cant push past 900mhz, while another unit runs perfectly at 1ghz. id say start @ 850 and slowly work your way up. but keep in mind your power supply also plays a big part with over clocking success. i use 5v 2000ma with great success, but ive read people having greater success with 5.1,5.2v units.
I use a 5.25 volt 2 amp regulated supply with mine. I think the extra voltage makes all the difference as even with cable voltage drop at maximum over-clock and load I'm still seeing 5.1 volts between TP 1 and TP 2, well above the safe minimum of 4.8 volts. With the over clock settings I listed earlier my Pi has been 100% stable. After reading a lot about instability of the Pi I've been very pleasantly surprised at just how stable mine is, even in other OS's like Raspbian.

Just for a laugh I tried powering it off a 10 watt iPad charger - in the same conditions it was only 4.3 volts! (Surprisingly it still booted and ran, but I wouldn't expect it to be stable)

As a general rule chargers do NOT make good power supplies for Raspberry Pi's...

RE: Pi help for a newbie - xbs08 - 2014-02-20

Afaik OE default GUI res is 1080 but you can change it to 720 in settings.

OE can use F2FS (EXT2, EXT3, EXT4) but there's a problem with guisettings.xml sometimes missing on boot after a crash and ocassionally OE won't boot if you use F2FS.

Also, the improvement is only noticable in writes, in reads EXT4 beats F2FS.

OE and Raspbmc don't work the same way so performance using F2FS is more noticable in Raspbmc.

Another thing is make sure you align the partition on the USB, i think GParted does this. In windows, you can use MiniTool.

RE: Pi help for a newbie - apeg - 2014-02-20

(2014-02-20, 18:16)Unicorn99 Wrote: For example, if I over clock to 850 and it becomes unstable, will it just be a case of reverting it back with no further issues ?
it all depends, it could just be unstable and cause reboots, so yes in that case just SSH in and bring the over clock settings down. But there is a chance you could corrupt your SD card, don't worry if that happens just take the SD card out give it a clean format and start again. (although i guess that depends on what version of openelec you are running, DBMandrake posted above that raspbmc fixed that issue after their December release... great to hear, thanks for the info DBMandrake)

If the version your testing with does corrupt the SD card it probably wont happen until you turn the over_voltage=6. which is 950mhz+

(2014-02-20, 18:17)DBMandrake Wrote: I use a 5.25 volt 2 amp regulated supply with mine. I think the extra voltage makes all the difference as even with cable voltage drop at maximum over-clock and load I'm still seeing 5.1 volts between TP 1 and TP 2, well above the safe minimum of 4.8 volts. With the over clock settings I listed earlier my Pi has been 100% stable. After reading a lot about instability of the Pi I've been very pleasantly surprised at just how stable mine is, even in other OS's like Raspbian.
Interesting, im going to pick up a 5.25 and see how the Pi does... and your 10w results are haleriouse, risky test lol

RE: Pi help for a newbie - DBMandrake - 2014-02-20

(2014-02-20, 18:26)xbs08 Wrote: Afaik OE default GUI res is 1080 but you can change it to 720 in settings.
Nope. I just installed a fresh OpenElec 3.2.4 on a spare SD card to double check and the GUI is definitely running in 720. The blurring from the up-scaling is obvious, as is the stutter to GUI animations.

Don't confuse GUI resolution with the resolution setting in Settings->System->Video Output - if that is set at 1920x1080, the HDMI output mode is 1920x1080 and 1080p videos will play at 1080p, however the GUI is still only rendered at 1280x720 and up-scaled to 1920x1080 so looks soft and blurred.

In Raspbmc this is also the default but if you enable "Remove UI res limit" the GUI is truly rendered at 1920x1080 - so the GUI is much sharper and paradoxically it animates smoother too. I can't see any equivalent setting in OpenElec, unless I've missed it.

RE: Pi help for a newbie - popcornmix - 2014-02-20

(2014-02-20, 18:49)DBMandrake Wrote: Nope. I just installed a fresh OpenElec 3.2.4 on a spare SD card to double check and the GUI is definitely running in 720. The blurring from the up-scaling is obvious, as is the stutter to GUI animations.

This depends on the build. Gotham builds default to 1080p (but allow a switch to 720p in GUI).
Frodo builds default to 720p (but there are hacks in some builds to get 1080p).

Be aware that performance in Gotham builds is considerably better.
It's probably advisable for a newbie to stick with Frodo for better compatibility with addons, but Gotham will be here soon so you have something to look forward to.

(Background: Frodo is the current stable version of xbmc. Gotham is the upcoming version of xbmc, currently in alpha, but moving to beta very soon).

RE: Pi help for a newbie - xbs08 - 2014-02-20

Thanks popcornmix, I should have mention that I was refering to Gotham builds.