LHC@home

Running in emulation mode under Qemu is super slow.
Benchmark says... running linux under emulation mode (using Qemu) gives you one third the speed.

Benchmark running knoppix emulated
Measured floating point speed 652.91 million ops/sec
Measured integer speed 1237.41 million ops/sec
http://lhcathome.cern.ch/show_host_detail.php?hostid=29097

Benchmark for a normal Knoppix session
Measured floating point speed 1754.39 million ops/sec
Measured integer speed 3596.78 million ops/sec
http://lhcathome.cern.ch/show_host_detail.php?hostid=5407

I recently DL'd the 3.8 Knoppix which has support for running the live CD in emulation mode from windows.
Emulation mode runs very very very very very slow.
At first, I thought there was an error in booting, but it turned out to be a 1 minute timeout to get past an error message on the third line in the boot sequence.

Emulated knoppix booted up after I came back home from shopping. Emulated knoppix is very sluggish... makes a 2.2 ghz machine feel like a 150 mhz machine.


One issue I noticed is that boinc (4.19 linux) connects to the einstein project to get preferences (assumed) even though this computer only had the LHC on it.
http://members.shaw.ca/joevoxxer/boinclhcEmulated.jpg

Link to story about latest Knoppix
http://slashdot.org/article.pl?sid=05/03/16/0210216&tid=185&tid=1
Link to torrent
http://www.boegenielsen.dk:6969/


Qemu is a processor emulator, so it's emulating the whole processor. I think running a LHC work unit to see if it validates would be an interesting test of whether Qemu properly emulates a floating point processor with enough precision.

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I'm not the LHC Alex. Just a number cruncher like everyone else here.

For one, that's a decent speed considering what Qemu does- I'd be interested to see how well it runs on Microsoft Virtual PC for sh*ts and giggles. :) I think 85-90% of real cputime would be achievable (runs off to fire VPC up). Anyone wanna see how well sixtrack runs in the Bochs x86 emulation environment?

[/cackle]

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> For one, that's a decent speed considering what Qemu does- I'd be interested
> to see how well it runs on Microsoft Virtual PC for sh*ts and giggles. :) I
> think 85-90% of real cputime would be achievable (runs off to fire VPC up).
> Anyone wanna see how well sixtrack runs in the Bochs x86 emulation
> environment?
>
> [/cackle]
>
>

Well, I tried it out because qemu was bundled with the knoppix disk.

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I'm not the LHC Alex. Just a number cruncher like everyone else here.