mersenneforum.org  

Go Back   mersenneforum.org > Great Internet Mersenne Prime Search > Hardware

Reply
 
Thread Tools
Old 2004-12-19, 03:08   #1
Uncwilly
6809 > 6502
 
Uncwilly's Avatar
 
"""""""""""""""""""
Aug 2003
101×103 Posts

22·3·683 Posts
Question Laptops, Batteries, and Prime95

Well, I got myself a new laptop (the 486-66 hasn't died yet...) and I am wondering about a few things.

1) If I keep it on a nice surface to keep it vented, I should be able to run P95 while it is plugged in. It's a Viao K35 running a Pent M @ 3.02
Will cooling be a huge issue?

2) I get different info from different folks. Would leaving it plugged in and running p95 for a week at a strech shorten the battery life span (I am talking total time until i must replace the batt.)?
To the best of my knowledge the batts are rated to a number of cycles.
Should I cyle the batt. once every week or two, even if I am not needing to use it "in the field"?

3) Any other issues?
Uncwilly is offline   Reply With Quote
Old 2004-12-19, 11:42   #2
Xyzzy
 
Xyzzy's Avatar
 
"Mike"
Aug 2002

7,559 Posts
Default

A Pentium M at 3GHz?

Personally, I know of several laptops that have failed running Prime95... One of them was my wife's... The heat was too much and it ruined the HD...

There is a throttle option though... Look in undoc.txt for more info...

If the laptop is plugged in, the battery shouldn't be used...

I never cycle batteries... The newer ones aren't affected by "memory" like the old ones were...

That said, I expect to lose battery capacity based on time, even if the battery is rarely used... I expect to lose 20% per year at least... I recommend to the people I set up with laptops to buy a new battery every 2-3 years, even if the laptop is being used as a desktop...

Edit: You have a Mobile Pentium 4 processor at 3.06GHz, not a Pentium M... Be aware that CPU is going to run a lot hotter than a Pentium M would...

Edit2: And it is a Prescott! 88W!

http://processorfinder.intel.com/scr...ALL&CorSpd=ALL

Note that max temp is 75C... That is very low IMO...

Note how the fastest Pentium M uses only 21W and is rated to 100C:

http://processorfinder.intel.com/scr...ALL&CorSpd=ALL
Xyzzy is offline   Reply With Quote
Old 2004-12-19, 18:18   #3
Axel Fox
 
Axel Fox's Avatar
 
May 2003

9610 Posts
Default

One thing I would like to add is that laptops (and especially P4's) have a pretty intensive venting set-up, which usually also attracts a lot of dust. In my laptop, it worked fine the first few months, but then I noticed that the iteration times were higher, because the CPU throttled constantly because it was too warm.

The problem was dust, the CPU didn't cool down efficiently enough to maintain maximum speed all the time. So what I recommend (and what solved my problem) is a can of compressed air and blow it through the ventilation holes once every week or so, to keep the CPU dust free.
Axel Fox is offline   Reply With Quote
Old 2004-12-20, 15:28   #4
Mystwalker
 
Mystwalker's Avatar
 
Jul 2004
Potsdam, Germany

11001111112 Posts
Default

Quote:
Originally Posted by Uncwilly
2) I get different info from different folks. Would leaving it plugged in and running p95 for a week at a strech shorten the battery life span (I am talking total time until i must replace the batt.)?
To the best of my knowledge the batts are rated to a number of cycles.
Should I cyle the batt. once every week or two, even if I am not needing to use it "in the field"?
The power requirements are no problem AFAIK. So the battery can serve as a UPS in case of power outages.
The only battery-related issue I know of is heat - the capacity drops faster the warmer the battery is. Normally, the temperature (of the battery) is around 20°C --> room temperature. With my IBM R50P and 1,7 GHz Pentium M, I currently have 27°C with full CPU utilization for hours. With a bad surface, battery temp. goes a little above 30°C.

Badly designed notebooks usually have their batteries nearer to the "temperature generators" (a.k.a. CPU, Video, HDD, maybe Heatsink/Ventilation system), so battery temperature will rise higher - especially with processors consuming more power.

Quote:
3) Any other issues?
Noise can be a problem as well. When your CPU is a Mobile P4-m, it should be ok for idle or office use. Otherwise, the fan will start - maybe it's quite quiet, maybe not...
Mystwalker is offline   Reply With Quote
Old 2004-12-20, 19:50   #5
Paulie
 
Paulie's Avatar
 
Aug 2002

223 Posts
Default

You will eventually have a heat related failure. I ran my IBM T30 (P4-M 1.7) 24/7 for 6 months, using the fan output to keep my coffee warm all morning.

One day, the memory wasn't detected anymore : Memory was fine, needed a new mainboard. Old memory worked fine, ran it for another couple months until I got an upgrade to a T41 (P-M 1.7) Don't run Prime on this machine for two reasons, 1) it's slower, and 2) I don't work in a lockable room anymore, now in cube'ville, so it comes home with me at night.

Make sure the machine doesn't lie flat on the bottom, it needs to be tilted to have that extra heat radiated from the casing.
Paulie is offline   Reply With Quote
Old 2004-12-21, 04:18   #6
E_tron
 
E_tron's Avatar
 
Sep 2002
Austin, TX

3·11·17 Posts
Default

My friends Duron based notebook suffers from Prime95 related heat. To prevent overheats, i suggested to keep the notebook vertical with the case vent up when he wasn't using it. The passive cooling helps alot.
E_tron is offline   Reply With Quote
Old 2004-12-21, 08:06   #7
Uncwilly
6809 > 6502
 
Uncwilly's Avatar
 
"""""""""""""""""""
Aug 2003
101×103 Posts

819610 Posts
Default

Quote:
Originally Posted by Xyzzy
There is a throttle option though... Look in undoc.txt for more info...
Gotta d/l a new P95 package, as I have just updated the .exe in the past and v22 undoc.txt did not seem to have anything on throttling.

Luigi's factor3_2 prog really got the fan spinning. I had the batt fully charge and unplugged it and it took it down into the 80% range in a fairly quick time.
Uncwilly is offline   Reply With Quote
Old 2004-12-21, 08:13   #8
ET_
Banned
 
ET_'s Avatar
 
"Luigi"
Aug 2002
Team Italia

3×5×317 Posts
Default

Quote:
Originally Posted by Uncwilly
Luigi's factor3_2 prog really got the fan spinning. I had the batt fully charge and unplugged it and it took it down into the 80% range in a fairly quick time.
And you still didn't try my (probably faster) alpha version 3.3

Luigi
ET_ is offline   Reply With Quote
Old 2004-12-21, 17:02   #9
nomadicus
 
nomadicus's Avatar
 
Jan 2003
North Carolina

2·3·41 Posts
Default

> "Make sure the machine doesn't lie flat on the bottom, it needs to be tilted to have that extra heat radiated from the casing."

Yes. Air flow and tilting it is important.
I've had very few problems with laptops. Me and the kids have 3 Dells. Combined total of roughly 80 P90 CPU years so far. I tortured one of them in a car trip; worked fine as long as air flow was good.
nomadicus is offline   Reply With Quote
Old 2004-12-22, 10:56   #10
patrik
 
patrik's Avatar
 
"Patrik Johansson"
Aug 2002
Uppsala, Sweden

23·53 Posts
Default

My Dell Inspiron 500m (Pentium-M 1500 MHz) died after 11 months of more or less continuously running Prime95. (Sometimes I turned if off at night, due to the noise, when I was using it in my bedroom.) Luckily the warranty lasted 12 months, so I got the motherboard replaced at no cost. The cause, as diagnosed by Dell, was "wrong battery". (It was the one that came with the computer though.) So I suspect the constant heating as the problem. I don't run Prime95 on it anymore.
patrik is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
1000 core chip that runs on AA batteries! tServo Hardware 12 2016-06-22 22:04
Capicitor batteries. mfgoode Science & Technology 14 2006-07-03 15:48

All times are UTC. The time now is 14:56.

Fri Jul 3 14:56:46 UTC 2020 up 100 days, 12:29, 2 users, load averages: 1.89, 1.54, 1.52

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.