Archive for November, 2010

How hot is too hot? Don’t overheat your computer.

When your computer’s processor, chipset, or hard drive overheats, you can wind up with big problems. From system slowdowns to application crashes, video corruption, data loss, to permanent damage to your computer hardware. It’s important to keep your computer running cool.

Your computer has sensors in various places to monitor the internal temperature and regulate the fan speeds. These sensors are typically in places such as your CPU, graphics card, hard drive, and maybe one in open air (typically in desktops). Unlike your car, there’s no easy indicator of what the temperature is until things start to go wrong, and those fans can only do so much. Dust can clog heatsinks and air passages, which can slow down the flow of air and drive the chip temps up. If a fan fails completely, it will stop the airflow and the temperature will climb rapidly. For those reasons it helps to have a program to actually tell you what these temperature sensor readings are. If things are getting a little too hot, you might want to know so you can check things out.

For Windows, two good utilities are Speedfan (free) and Everest . For Ubuntu, two good programs can be found in Synaptic: sensors-applet and hddtemp.

Those programs will read the temp sensors and tell you the values. Unfortunately, these numbers won’t mean very much if you don’t know what the limits of your hardware are. For example, while typing this article on my laptop, my CPU temp is 35C (95F). While that might sound hot to some, the thermal design limit of my CPU is actually 105C (source: Intel). I know my processor is well within the design limits.

That said, here’s a list of a few common chipsets and their operating limits:

Various Intel Core 2 Duo (Desktops):

Models E6700 (2.66 GHz), E6600 (2.40 GHz), E6420 (2.13 GHz) and E6320 (1.86 GHz): 60.1 C (140 F).
Models E6400 (2.13 GHz), E6300 (1.86 GHz), E4400 (2 GHz) and E4300 (1.8 GHz): 61.4 C (143 F).
Models E6850 (3 GHz), E6750 (2.66 GHz), E6550 (2.33 GHz) and E6540 (2.33 GHz): 72 C (162 F).
Models E4500 (2.20 GHz) and E4400 (2 GHz): 73.3 C (164 F).
Source: Core 2 Duo Temperature Limit | eHow.com

Various laptops by manufacturer and chipset:

Dell Latitude D620 (using T7600 CPU): 100C
Dell Latitude D630 (using T7700 CPU): 100C
Toshiba Satellite A215-S7422
(using AMD Turion 64 X2): AMD Doesn’t say — See guidelines below

(I may add to this list as time goes on)

I’ve been seeing a lot of conversation about the nVidia Quaddro mobile chipset and it’s failure temp. While I haven’t been able to find anything official, I have been able to keep my chip under 80C and haven’t experienced a problem to date. See also: Disclaimer.

If you want to find the correct spec for a specific Intel product, you can use Intel’s ARK lookup.For AMD, try the AMD Product Specification lookup. For hard drives, check the manufacturers spec page for your specific drive.

However bear in mind when using these spec sheets that the given specs are for the components themselves under controlled conditions. Chipsets are likely to become unstable before reaching these temps, and heat run-off may damage nearby components on circuit boards. Additionally, occasional manufacturing defects can cause chip failures before these temperatures are reached. I would always suggest to try to stay at least 15-20C below the rated temperature.

If you can’t find specific temps for your chipset, good guidelines would be to try to stay below the following temps:

55C for desktop CPUs, 85C for laptop CPUs.
75C for desktop GPUs, 75C for laptop GPUs.
55C for desktop HDDs, 45C for laptop HDDs.

These are merely a reference point. While some chipsets may tolerate higher temps better than others, cooler is always better. See also: Disclaimer.

FAQ: Why are the rated chipset temps so much higher for laptops?

Laptops are by their very nature smaller and lighter than their desktop counterparts. In order to accommodate this, you will find laptops have smaller fans, heatsinks, and internal airways. Additionally, instead of fan-heatsink-chip assemblies, laptops often feature fan-heatpipe-chip assemblies, which locates the fan further from the chip. Mobile chipsets are thus designed to have higher operating temperatures because heat cannot always be dissipated quickly and occasionally the airways may become blocked. In addition, the higher operating temperatures allow the fans to cycle off to conserve battery power.

One last point worth mentioning is to make sure you’re using the latest OEM BIOS for your computer, especially for mobile machines. BIOSes often have a fan speed table in them which is what sets the fan speed based on the chipset temperature. You can typically find the BIOS update listed on the manufacturer’s website.

If you believe any of the information I have posted above is incorrect, or you would like to ask me to post data on a specific chipset, please leave a comment below. If you have any information to contribute, please do so in the comments. If you want to share this information, please do so as a link to this page for the sake of updates. Thank you.

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Dell Latitude D630 touchpad “jumping” mouse cursor

A friend and I have been discussing an issue we’ve both been seeing on our laptops: The mouse cursor “jumps” when using the touchpad. It’s intermittent, unpredictable, and seemingly random, but it seems to jump about 3 inches straight up on the screen. It seems to happen only on Windows-based OSes; We both installed Ubuntu Linux at a point and didn’t notice it at all.

He pointed me to the R165805 Dell Touchpad / Pointing Stick driver from the Dell website.

I am using it on a D630 with Windows 7… it works, and solves the problem.

The listed compatibility is:

Systems Latitude D530
Latitude D630c
Dell Precision Mobile WorkStation M2300
Operating systems Microsoft Windows Vista 64-bit

Update 2/10/2013: gund brought to my attention that the download link is no longer active. Here is a direct link to the R165805.EXE file on Dell’s FTP site. If that ever becomes unavailable, you can try this driver, but I haven’t tested it myself: R165804 Dell Touchpad / Pointing Stick.

 

I’ll welcome any comments on this.

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Twitter Follower Count in PHP using Twitter REST API

Here’s an easy way to display the number of Twitter followers you (or another user) have in PHP using the Twitter REST API.

This was based off NealGrosskopf.com but was revised to use the Twitter API and not require a logged-in session.

First, declare the necessary functions:

<?php
function curl($url) {
  $ch = curl_init($url);
  curl_setopt($ch,CURLOPT_RETURNTRANSFER, true);
  curl_setopt($ch,CURLOPT_HEADER, 0);
  curl_setopt($ch,CURLOPT_USERAGENT,"__YOUR_DOMAIN__");
  curl_setopt($ch,CURLOPT_TIMEOUT,10);
  $data = curl_exec($ch);
  curl_close($ch);
  return $data;
}

function GetTwitterFollowerCount($username) {
  $twitter_followers = curl("http://api.twitter.com/1/statuses/user_timeline.xml?count=2&amp;screen_name=".$username);
  $xml = new SimpleXmlElement($twitter_followers, LIBXML_NOCDATA);
  return $xml->status->user->followers_count;
}
?>

Now, a simple function displays the count:

<?php
echo GetTwitterFollowerCount("__USER_NAME__");
?>

Replace __YOUR_DOMAIN__ with the domain of the page making the API call, and __USER_NAME__ with the name of the user you want the information on.

Works for me.

UPDATE: For some reason, count=1 broke, but it works with count=2. Either change to count=2 (to reduce the download size) or omit the count= parameter completely (but it can inflate the download size if you have a lot of followers.)

UPDATE 2: If you are using this to fire on every page load, make sure you don’t exceed the Twitter API Rate Limit. If you think you may, you might want to cache the results, else risk being blacklisted by the Twitter API.

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Bad robots

As part of being on a VPS, bandwidth is limited. One of the things you have to watch for is bots, crawlers, and scrapers coming and stealing your content and bandwidth.

Some of these bots are good and helpful, like the Google, Yahoo, and Bing crawlers. They index your site so it will appear in the search engines. Others, like the Yandex bot, crawl and index your pages for a Russian search engine. If you have an English-only site targeting US visitors, you might want to consider blocking the Yandex bot.

In my searches I also came across the Dotbot, which seems to crawl your pages just to get your response codes. I’m not sure what they do with the data, but in my opinion it’s better to block them.

So how does one block these bots? The Robots Exclusion Protocol states that a file, called robots.txt, can be put in your DocumentRoot with directives for bots to follow. For example, if your domain is example.com, your robots.txt should be at the following URL:

http://example.com/robots.txt

The robots.txt directives can tell bots which files they are allowed to index and which they are not. Well-behaved web robots will look at this file before attempting to crawl your site, and obey the directives within. The directives are based on the bots UserAgent string. A couple of examples:

Block the Dotbot robot from crawling any pages:

UserAgent: dotbot
Disallow: /

Block all robots from crawling anything under the /foo/ directory:

UserAgent: *
Disallow: /foo/

The Google Webmaster Tools has an excellent tool for checking your robots.txt file. You can find instructions on how to access it here. Google account required.

However, not all bots obey (or even look at) the robots.txt file. Those that don’t need special treatment in the .htaccess file, which I’ll describe in another post.

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DMCA Safe Harbor, Net Neutrality, and the COICA Bill

This article is a rewrite of a previous article which was originally posted by myself at another site. This rewrite introduces information that was not part of the original article.

After reading an article on Net Neutrality, which is no longer available to cite, and some old but relevant news about the COICA Bill (which never became law), I was caught by the clash between the attempted censorship of the Internet by ISPs and the DMCA’s Safe Harbor provision. That’s the provision that allows ISPs and web hosting companies to remain unharmed if a user posts copyright-infringing material on a network or web hosting service provided by them. The idea behind this is that it’s the user, not the company, who is responsible for the copyright infringement. The ISP or web host (the provider) is just a conduit and is not responsible for the user’s infringing material.

The important point to note is that there are very specific conditions to the DMCA Safe Harbor provisions that strongly support the position of net neutrality, one of which is 17 U.S.C. Sec. 512 (b)(2)(C):

the service provider does not interfere with the ability of technology associated with the material to return to the person described in paragraph (1)(A) the information that would have been available to that person if the material had been obtained by the subsequent users described in paragraph (1)(C) directly from that person, except that this subparagraph applies only if that technology –

  • (i) does not significantly interfere with the performance of the provider’s system or network or with the intermediate storage of the material;
  • (ii) is consistent with generally accepted industry standard communications protocols; and
  • (iii) does not extract information from the provider’s system or network other than the information that would have been available to the person described in paragraph (1)(A) if the subsequent users had gained access to the material directly from that person;

So what does this mean? A service provider cannot interfere with the transmission of a protocol or data that (i) does not signifigantly impact the performace of their network, (ii) follows accepted Internet technology protocols, and (iii) does not affect the privacy or their users/customers. If a service provider violates these terms, they cannot expect to be protected under DMCA Safe Harbor.

That said, proponents of net neutrality have a really big card in their pocket with 17 USC 512, and should be using it as leverage in the fight for net neutrality.

What are your thoughts on this?

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Restoring Ubuntu Gnome Panels

If you’ve mangled, deleted, or otherwise borked your Ubuntu Gnome panels, here’s a way to revert them back to the default appearance and positioning.

You’ll want to open the ‘run’ dialog via ALT-F2 and enter each of the commands one at a time, followed by enter.

gconftool --recursive-unset /apps/panel
rm -rf ~/.gconf/apps/panel
pkill gnome-panel
gksu reboot

That should do it. When the system comes back up, all should be back the way it was.

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