Moving on to the power efficiency of the notebooks, the thermal design power (TDP) of the respective platforms would be a good indicator for starters. While we don't know the entire platform's TDP, we do know that the Intel Core 2 Duo SU7300 processor's TDP rating is just 10W, while the AMD Turion Neo X2 L625 requires much more juice at 18W. This discrepancy is mostly in due to the 45nm and 65nm engineering process used to manufacture the Intel and AMD mobile processors respectively. This does mean on paper alone, the AMD solution would be faced with higher power consumption and thus a lower battery life. This is because both platforms are using the same HP Pavilion dm3 design components of which the 6-cell battery pack is identically rated for 57Wh capacity. But how much of a discrepancy in operating time are we talking about?
To find out, we used our usual video looping test which loops a 720p trailer until the battery goes flat. On battery life alone, the Intel machine managed more than 70% longer battery life than the AMD machine; and the advantage widened when testing in discrete mode. For those thinking if ATI's Hybrid CrossFire was actively sapping more power - the answer is no. The chipset supports this form of CrossFire, but only with much older generation discrete mobile GPUs of the HD 3450 and 3470 range. As such the discrete graphics performance is solely that of the Radeon HD 4330. Instead, ATI's PowerXpress technology allows users to manually switch between their preferred GPU usage mode depending the task at hand; take note that this is a manual option. Therefore, there's no mixing up other possibilities of the less than desired battery life outcome other than the more power hungry nature of the AMD platform or a poor optimization of the notebook by HP.
Drilling the numbers down to calculate the power consumption figures, we can see in the chart below that Intel is still leading the way, and as such we don't expect it to change even for the Portability Index calculation that's coming up shortly. With Intel platform's 10.21 watts power consumption, it handily beats the AMD platform which had power consumption figures of 17.92 watts and 25.11 watts when using the IGP and discrete graphics mode respectively.
Lastly on our Portability Index which is a measure of, well, how portable a notebook is conisdering its physical attributes and battery uptime. We derive this using a simple formula by using the notebooks's battery uptime and dividing it by the product of the unit's weight and volume; the higher the ratio, the more portable the unit is - applicable for direct comparison only within the same category of notebooks. The outcome? Intel's platform came out tops of course. This HP Pavilion dm3 garnered a higher ratio of 1.402 that's far more favourable than the AMD based unit that managed 0.799 (IGP) and 0.57 (discrete graphics).
As for the ratio obtained by the Intel platform based HP Pavilion dm3 compared with others of its class, it was actually among the highest like the Acer Aspire Timeline 3810T, LG T380 and few others. All isn't lost for the AMD platform based dm3 as the Dell Inspiron 13z using the Intel CULV processor platform is actually looking quite bad for its specs and capabilities. In fact, the AMD platform still has a decent portability ratio considering how much better it can handle entry-level gaming needs, even when considering the discrete graphics option.