Mobile CPUs: Penryn vs Core

Posted at: Thursday 13th March 2008 by Clive Webster

We put Intel's new 45nm, Penryn-based mobile CPU to the test against a compartively priced, older 65nm Core-based mobile CPU.

EDAT: DYNAMIC OVERCLOCKING

The final new technology is EDAT, or Enhanced Dynamic Acceleration Technology, which aims to increase performance in single-threaded applications. EDAT works by overclocking core 0 when core 1 is unused and powered down, as the CPU can’t exceed its thermal design power (TDP). Testing EDAT is tricky, as most current applications are multithreaded, but Cinebench R10 can be set to address only one core. However, Windows Vista (and XP) still splits this work evenly across the two available cores. This means that should you want to launch another application, there’s sufficient processing headroom on either core to maintain your PC’s responsiveness, but it also means that EDAT can’t kick in. Even setting the Cinebench test to address only core 0 didn’t see any EDAT overclocking, as Vista kept bumping essential Windows processes to core 1 to try to keep the PC responsive.

Eventually, we had to set the affinity of every process to address only core 0, which enabled EDAT to work. However, it raised the multiplier of the fully loaded core 0 by just 0.5 – a feeble 100MHz overclock – and the Cinebench score didn’t increase noticeably, as core 0 now had to run the entire OS as well as Cinebench. Considering that we had to run a benchmark in a synthetic way just to see EDAT work, we can safely say that it’s better suited to Windows 98 than Windows in 2008.


CONCLUSION

While EDAT is as useful as a chocolate teapot in this modern age of multi-threaded applications and Windows multi-core load-balancing, the other enhancements in the new 45nm mobile Core 2 Duos are great. The extra speed and battery life for roughly the price of a 65nm Core-based CPU are very welcome