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---- Thread: OpenELEC Testbuilds for RaspberryPi Part 2 (/showthread.php?tid=184866)



RE: OpenELEC Testbuilds for RaspberryPi Part 2 - doveman2 - 2013-12-17

(2013-12-17, 15:23)MilhouseVH Wrote: Seems OK, you can probably lose the "<streamsilence>" settings as that is now supported in the GUI settings. Same for "<guires>".

Do you still need to set a manual timezone? I've never had this problem (I'm in the UK too).

Cool, thanks for checking it for me Smile

I certainly did need to set the timezone manually a few builds back. I recall a few other people had the same problem and just putting it in guisettings.xml didn't work for me at least. I'll try taking it out again though and see if it no longer needs to be there.


RE: OpenELEC Testbuilds for RaspberryPi Part 2 - Reddog999 - 2013-12-17

Not trying to steal xbs08's thunder but I thought I would try running MilhouseVH's latest build with a f2fs storage partition on a usb drive - and, well, everything appears to be working!

As to running faster, it appears to be when going through my movie collection (fanart view) but that might just be subjective.

Are there any 4kb write speed tests I can perform to compare against an ext4 storage partition?


RE: OpenELEC Testbuilds for RaspberryPi Part 2 - xbs08 - 2013-12-18

Try iozone.org


Interesting benchmarks...

http://www.phoronix.com/scan.php?page=news_item&px=MTQ1OTE

http://www.solid-run.com/phpbb/viewtopic.php?f=2&t=1373


RE: OpenELEC Testbuilds for RaspberryPi Part 2 - Koloss - 2013-12-18

Very good news! I hope in future it is in our build included!


RE: OpenELEC Testbuilds for RaspberryPi Part 2 - gummibaum - 2013-12-18

(2013-12-18, 11:18)xbs08 Wrote: Interesting benchmarks...

http://www.phoronix.com/scan.php?page=news_item&px=MTQ1OTE

http://www.solid-run.com/phpbb/viewtopic.php?f=2&t=1373

well,
the results may be interesting, but:

  1. The first link goes to an article which did some "cherry picking" from the complete results provided here.
    There you'll see, that F2FS may be ways worse than EXT4.
  2. The second linked document shows, that F2FS is faster when writing, but does provide (near) zero improvement for reads.
    In everyday life, reads account for >> 90% of "disk" accesses
    (and I'm pretty confident this is the case with XBMC as well).
So: no need to hurry implementing F2FS.


Mathias


RE: OpenELEC Testbuilds for RaspberryPi Part 2 - xbs08 - 2013-12-18

Did a quick run with F2FS and the performance is about the same as ext4.
Maybe there will be improvements when scanning the library.

Agree, no hurries.


RE: OpenELEC Testbuilds for RaspberryPi Part 2 - allan87 - 2013-12-18

(2013-12-18, 22:30)xbs08 Wrote: Did a quick run with F2FS and the performance is about the same as ext4.
Maybe there will be improvements when scanning the library.

Agree, no hurries.
Bet it won't help. Not that I know that much, but it seems to me that there are several bottlenecks and writing to flash wouldn't be the major factor. Judging how little effort it takes to get the Pi up to 100% use of its CPU, that's going to be the main issue. I have never checked, but I bet it's at 100% when its scanning.

If python routines are being used - well python is super slow on the Pi and, if practicable, improvements in python performance (and improvements to the routines) would probably make much more of a difference. A faster, not yet in existence version C Pi wouldn't hurt.


RE: OpenELEC Testbuilds for RaspberryPi Part 2 - popcornmix - 2013-12-18

(2013-12-18, 22:58)allan87 Wrote: Bet it won't help. Not that I know that much, but it seems to me that there are several bottlenecks and writing to flash wouldn't be the major factor. Judging how little effort it takes to get the Pi up to 100% use of its CPU, that's going to be the main issue. I have never checked, but I bet it's at 100% when its scanning.

But that argument would suggest that switching from sdcard to USB for the main storage is pointless, yet there it clearly has a significant benefit.

It's been reported here that USB sticks with good 4K write performance make xbmc more responsive when busy scanning or updating.
I'd imagine that is the sort of scenario where f2fs will be beneficial.


RE: OpenELEC Testbuilds for RaspberryPi Part 2 - allan87 - 2013-12-18

I certainly yield to your far superior knowledge. I note, however, that the benchmarks showed no improvement in read performance for F2FS, whereas read performance was materially improved in the instances where switching from sdcard to USB made a difference.

What do you say about the processor/python/python routine bottleneck?


RE: OpenELEC Testbuilds for RaspberryPi Part 2 - xbs08 - 2013-12-18

Even if the read speeds are more or less the same I prefer to have faster write times over slower ones.


RE: OpenELEC Testbuilds for RaspberryPi Part 2 - Milhouse - 2013-12-19

(2013-12-18, 23:23)allan87 Wrote: What do you say about the processor/python/python routine bottleneck?

If the recent changes to SportsDevil are anything to go by, poor Python add-on performance might be solved by profiling and judicious tuning.


RE: OpenELEC Testbuilds for RaspberryPi Part 2 - Reddog999 - 2013-12-19

I'm not sure if this is a fair or even useful comparison and I will probably get shot down by some of the more knowledgeable people on this forum but I tried copying my thumbnails folder to another location on the storage usb using:
"time cp -r /storage/.xbmc/userdata/Thumbnails/* /storage/downloads/Thumbnails"

With the ext4 formatted storage the time to copy 243,517,211 bytes (6,977 files) was 9m:54.36s => 0.4066 MB/s
I then ran "time rm -rf /storage/downloads/Thumbnails/" and this took 4.10s

With the f2fs formatted storage the time to copy 243,721,615 bytes (6,989 files) was 2m:41.87s => 1.4359 MB/s
Delete took 2.81s

I ran the test 3 times on each and time taken was within 5%.

This was using the same usb stick - a 4GB Sandisk Cruzer.

Assuming this has any meaning that represents a 3.5x performance gain with f2fs.


RE: OpenELEC Testbuilds for RaspberryPi Part 2 - xbs08 - 2013-12-19

Thank you Reddog999 for taking the time to do these test and for posting them here.

I assume copying from other device will improve those times.


RE: OpenELEC Testbuilds for RaspberryPi Part 2 - popcornmix - 2013-12-19

(2013-12-19, 18:00)Reddog999 Wrote: I'm not sure if this is a fair or even useful comparison and I will probably get shot down by some of the more knowledgeable people on this forum but I tried copying my thumbnails folder to another location on the storage usb using:
"time cp -r /storage/.xbmc/userdata/Thumbnails/* /storage/downloads/Thumbnails"

Seems a valid test to me. I'm surprised the difference was so great, but this is certainly interesting information. Thanks.

What might be interesting is installing a new add-on or skin. I think the write speed would be significant in that.
I seem to remember Aeon Nox took a couple of minutes to install. Installing from a zip file would avoid internet download speed being the bottleneck.

Another test would be something like:
Code:
./texturecache.py C movies
Again that might be dominated by internet download speed or jpeg decode/encode, but it might show a difference.


RE: OpenELEC Testbuilds for RaspberryPi Part 2 - xbs08 - 2013-12-19

My Thumbnail folder is 151 MB...

OpenELEC:~ # time cp -r /storage/.xbmc/userdata/Thumbnails/* /storage/downloads/Thumbnails
real 0m 31.39s
user 0m 0.19s
sys 0m 3.33s
OpenELEC:~ # time rm -rf /storage/downloads/Thumbnails/
real 0m 0.68s
user 0m 0.02s
sys 0m 0.30s

Can this be right??


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