A Little Overclocking: Record Set for Phenom II under Linux
For real overclocking you need liquid nitrogen and helium. All you need to do in winter is open your window.
The Phenom II Z940 processor from AMD provides a maximum clock rate of 3 GHz out of the box. Now news from Slashdot.com reports that a group of overclockers has increased the rate to 6.5 GHz, an apparent new record. The trick was to get temperatures down to minus 232 degrees Celsius, close to absolute zero.
We didn't want to go to such extremes in our own testing, so we simply put the test system on the window sill at 5 degrees Celsius. We then did an overclocking, even though our mainboard was a bit old for the Phenom II.
The Asus M3A78-EM motherboard provides a few tuning possibilities, but the BIOS completely ignored the frequency multiplier setting. Instead we used one of the three available overclocking profiles for five, eight and 10 percent faster rates. We started the first test at 5%, but soon discovered to our surprise that /proc/cpuinfo showed a 3,000 MHz frequency even under load. The benchmark results then improved markedly.
As a control, we raised the Z940 to the maximum 3.3 GHz allowed by the overclocking profile and, alas, the benchmark results were even better. Power consumption was also higher, showing that the CPU was truly running at 3,000 MHz, even though it had little effect on the 64-bit openSUSE 11.1 kernel.
We then wanted to see how far we could go and raised the rate above the reference clock to 3.75 GHz. The result was a panic error from the openSUSE and Ubuntu 8.10 kernels and the CPU could no longer keep up. Running at 3.375 GHz was still OK for the Phenom II, but 3.5 and 3.6 GHz showed sporadic crashes. An even colder environment and better test technology might have pushed the Z940 a bit further.
A glance at the graph might prompt the reaction that the the Phenom II is eight times faster than the Atom. Not quite correct, because the graph shows only a single core. In actuality, the AMD CPU can convert four .wav files with a factor of 38 into Ogg Vorbis format, working at about double clock rate with a resulting factor of 30 faster than the Atom N270.
Naturally we also started a short test on the i7 system. Needless to say the AMD clearly beat the equally clocked quad processor from Intel. The i7 (without overclocking) reached a factor of 33. Our Ffmpeg benchmark, however, proved the Intel ahead by a nose because of its hyperthreading support, and the AMD CPU had to be clocked at about 3.8 GHz to achieve the same results.
Comments
comments powered by DisqusSubscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
Canonical Releases Ubuntu 24.04
After a brief pause because of the XZ vulnerability, Ubuntu 24.04 is now available for install.
-
Linux Servers Targeted by Akira Ransomware
A group of bad actors who have already extorted $42 million have their sights set on the Linux platform.
-
TUXEDO Computers Unveils Linux Laptop Featuring AMD Ryzen CPU
This latest release is the first laptop to include the new CPU from Ryzen and Linux preinstalled.
-
XZ Gets the All-Clear
The back door xz vulnerability has been officially reverted for Fedora 40 and versions 38 and 39 were never affected.
-
Canonical Collaborates with Qualcomm on New Venture
This new joint effort is geared toward bringing Ubuntu and Ubuntu Core to Qualcomm-powered devices.
-
Kodi 21.0 Open-Source Entertainment Hub Released
After a year of development, the award-winning Kodi cross-platform, media center software is now available with many new additions and improvements.
-
Linux Usage Increases in Two Key Areas
If market share is your thing, you'll be happy to know that Linux is on the rise in two areas that, if they keep climbing, could have serious meaning for Linux's future.
-
Vulnerability Discovered in xz Libraries
An urgent alert for Fedora 40 has been posted and users should pay attention.
-
Canonical Bumps LTS Support to 12 years
If you're worried that your Ubuntu LTS release won't be supported long enough to last, Canonical has a surprise for you in the form of 12 years of security coverage.
-
Fedora 40 Beta Released Soon
With the official release of Fedora 40 coming in April, it's almost time to download the beta and see what's new.
Re:Voltage
But perhaps you can post your settings, so other readers can test them as well.
Voltage ?
Have you increased the voltage while OC ? I have the same processor and I could bum it to 3.8 with a little bump in voltage.. once can achieve 4ghz + @ increased voltage and with the help of a better cooler and cooling solution.. No Nitrogen and Helium needed
Regards