On a laptop with a dual-core:
1) single processor running 100% of the time
OR
2) both processors on a time throttle (give a % value)

Anyone want to ring in on the merits/drawbacks of either option?

Greatly appreciate it!

one thread would definitely be better - there's more cache available for that single core then.

There's a good chance you can run both cores for little more power/heat than a single core currently does if you undervolt though. I use RMClock (free from here]) on lots of machines. I believe power consumption/heat output increase with the square of the voltage but only linearly with clock speed, you can get big savings by undervolting (whether you run rosetta or not).

I've undervolted my T7500 from 1.325V to 1.100V which is a 31% power reduction, but I'm fairly sure i can drop it a fair bit lower.

The process is:

Install Prime95

Install RMClock and open it

In 'Profiles' set Current to 'Performance on Demand' (unless you want to run at max speed all the time, in which case use either Power Saving or Max Performance).

Then tick the multipliers you want to be used - I just have the highest two checked as i'm always running Rosetta (one of the two I've checked is IDA - it allows a single core on Intel mobile CPUs to run a bit quicker for certain apps)

Go into the 'Performance on Demand' and check ‘Use P-state transitions’ for AC and Battery and make sure the multipliers you want to use are checked below.

Start Prime95

Go back to ‘Profiles’ and drop the voltage of the highest multiplier that you’ve selected and ‘Apply’

Leave it for a couple of hrs to make sure Prime95 is still stable.

I tend to drop it quite quickly at first and then slower as I get towards and below 1.1V. If Prime95 fails then increase the voltage a notch and leave it running for a few more hours. I tend to bump it up one notch from the lowest Prime-stable voltage just to be safe.

HTH
Danny

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On a laptop with a dual-core:
1) single processor running 100% of the time
OR
2) both processors on a time throttle (give a % value)

Anyone want to ring in on the merits/drawbacks of either option?

Greatly appreciate it!

One other thing....BACKUP!!!! A laptops harddrive is not designed to be used all day long, it is designed to be used intermittently. Boinc writes to the harddrive all day and night long, every 60 seconds!! Over time this will cause problems with the integrity of your drive. Now lots of people use laptops to crunch with, I do! But I used to crunch with my older laptop, a 1.4ghz Celeron single core Toshiba and the harddrive crashed TWICE!! First time I recovered it, the 2nd time I replaced it, it no longer crunches. My Dell laptop, a dual core, does still crunch but only on one core, it sits on a laptop USB fan thing and is backed up every day! Your mileage may vary, but be aware of the potential for problems. BTW my Toshiba is what I am typing this on, so I do still use it, just not for crunching anymore!

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Thanks for all the advice! You were both very helpful

Thanks for all the advice! You were both very helpful

I use Rosetta on my laptop, a 2.4GHz Core 2 Duo, Dell Studio. I just leave the edge of the laptop with the cooling fan hanging over the edge of my desk and it keeps the CPU around 40-50 degrees Celcius. That's running both cores 100% with no change to voltage or clock speeds. Had no issus with the hard drive yet (only had it 10 months) but mikey gives good advice to back it up because it is a risk.

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Is time-throttling recommended?

i.e. is 1 of 2 cores at 50% throttle significantly less damaging to a laptop than 1 of 2 cores at 100% throttle?

hhiji, it is really more a matter of the heat output and battery. You probably do not want BOINC to be running when you are under battery power. And if you actually use your laptop on your lap, 100% CPU usage can get rather hot on some models.

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Rosetta Moderator: Mod.Sense

And if I run off AC power?
Mainly I am concerned about wear on the processor: whether 50% throttle is really better than continual load.

And if I run off AC power?
Mainly I am concerned about wear on the processor: whether 50% throttle is really better than continual load.

Continual 100% load on one processor will not damage it provided it stays below the maximum safe operating temperature as stated by the manufacturer. Running on AC is advisable because BOINC running will run your battery down pretty quickly however, this will greatly shorten the lifespan of your battery because they discharge when connected to the mains for long periods of time. If your battery goes, then your laptop will probably be out of action until you get a new one because even when it is plugged into AC, the laptop itself still runs of the DC current coming from the battery (there are a few exceptions to this - depends on make and model).

seriously guys - spend 10 mins getting RMClock running on it and the power consumption, temp, fan speed etc will all drop noticeably and the battery life will increase equally.

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I run both cores @ 100% almost all day... the T8300 (the Penryns I believe) run incredibly cool under stress.

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I also run both cores at 100% for 24/7 on by C2D T7200 and it still works great.

And if I run off AC power?
Mainly I am concerned about wear on the processor: whether 50% throttle is really better than continual load.

The processor is not a problem I have ever had with any pc running Boinc. I have been running Boinc since the beginning, and regular Seti before that! Like I said before the hard drive on laptops is the issue, not the cpu. Yes running the cpu at 50% means you are only using one core on a dual core system, however it means 2 cores on a quad core system. I believe the cpu will last longer than you want to keep the machine, even when running at 100% 24/7.

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And if I run off AC power?
Mainly I am concerned about wear on the processor: whether 50% throttle is really better than continual load.

The processor is not a problem I have ever had with any pc running Boinc. I have been running Boinc since the beginning, and regular Seti before that! Like I said before the hard drive on laptops is the issue, not the cpu. Yes running the cpu at 50% means you are only using one core on a dual core system, however it means 2 cores on a quad core system. I believe the cpu will last longer than you want to keep the machine, even when running at 100% 24/7.

I'd second this - the CPU is very rarely the problem (the Palomino Athlon I think was the last without thermal throttling?). The fan is more likely to be a problem, but it's still minimal. If you're worried about the hard drive you could run from a cheap (but preferably quick) USB flash drive.

I'll put some instructions up for RMClock this weekend - it's worth doing even if you don't run BOINC to cut your power bill, make your laptop battery last longer and keep the machine cooler/quieter... unless you want a static CPU speed and can drop the voltage in the bios...

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