I'm working on optimizing the memory thoughput of glibc.


The benchmarks highlighted one interesting fact:
At least one old Pegasos Firmware versions
is bootlenecking the performance of the Pegasos G4.


Its propably a good idea to test your memory throughput on your Pegasos to verify that you are not accidently using such a firmware.


Higher bars mean higher performance.


Old Firmware


Same machine with Newer Firmware




Here is the my testprogram (linux static binary)

http://www.greyhound-data.com/gunnar/glibc/stream02.gz

Gunnar

interesting gunnar, i'll try your testprogram as soon as possible (probably tonight) and send you the results.

This could perhaps be interesting, but these particular diagrams tell us nothing; the only thing I see is a bunch of colored bars and some numbers to the left.

Hi Gunnar,

actually this "performance brake" firmware is not
an old one but too new!

I had 1.2 2005 0602 111 451 that came with my latest
board (thanks to Genesi for the Peg1-upgrade!).

Downgrade to 1.2 2004 0810 112413 fixed the performance
to more than double speed!

Regards,
Peter

PPCNUX did a comparison between Pegasos II with the latest publicly available v1.1 firmware upgrade from bplan and the Freescale ODW with v1.2.

With the same RAM the memory latency went down from 192 ns (!) to about 176 ns, the STREAM copy bandwidth rose from 324 to 370 MB/s (tested with lmbench).

At this time I cannot explain the low numbers you displayed in the top graphic. Maybe the bus ran in 60x mode?

Imho it would be nice to check and set memory access timing in the OF, just like every PC board and even AmigaOne is able to.

@takemehomegrandma

Yes you are right. Stupid me forgot to add the legend.
You can read more about the test on this page: http://www.greyhound-data.com/gunnar/glibc/

@Peter
Thanks for clarifying which firmware it was.

@Arno
Yes your guess is propably right.
The performance looks very much like running in 60x bus mode.
The diagram looks very similar to the Aone G4 which run in60x bus mode.

One the Pegasos 2 there is of course still the option to use the DMA-Engine for copying memory. The throughput of the DMA Engine is in the range of 500% of what MorphOS or Linux are now able to archieve.

The major changes in firmwares have been in memory configuration. Some people will see improvements (especially using overspecced memory like PC3200) and some people may see a drop (but this is because the memory is configured properly, and adds more DIMM models to the "working" list)

However downgrading different 1.2 firmwares is NOT a good idea. The firmware you got with your board is the firmware that should be run on the board! Lower versions do not support the new clock chip on the 2B5 boards.

When you all get 1.3 all your performances will align anyway. Please do not downgrade your firmware.

_________________
Matt Sealey

any idea about the 1.3 release date ? And could you tell us about the changes in this version ?

Hi Neko, thanks for clearing that up. I only noticed
this later - the TOD-clock is indeed runnnig much too slow
after the downgrade.

Regards,
Peter

Booting from USB mass storage, DHCP etc. and a handful of other pretty things which are fairly silent in operation.

Some CHRP compliance fixes for things like disk number ordering is the only thing you will notice as a user (it will break the boot menu until you edit it

_________________
Matt Sealey

@Neko

booting from USB is something i will definately notice
thanks for the info.

Hmm, new features sounds realy nice. There is only one question ... when.

When it's been through feature-freeze and testing.

I talked with Sven and we agreed on some "must be done" features and bugfixes, and anything "still in development" would be disabled for the freeze. This should enable a fast track to test and then release and hopefully coincide with an EFIKA shipment.

After that any of the development parts (which including perhaps other filesystem support, and HAL improvements which will benefit installers for Linux etc.) might get a fast tracked "1.3.1" release.

I hope after this long, long wait we can finally start doing something like 2 or 3 firmware updates per year, and finally the Pegasos I update to bring it to parity.

We also have an improved manual for 1.3 which will go out with the release - or maybe even sooner.

_________________
Matt Sealey

Hi Matt,

Many thanks for the status report.
This is in fact very good news!

I'm not sure if I understood this correct.
Will 1.3 be available for Peg1 too or is the Peg1 update planned be come out later?

Cheers
Gunnar