CPU Rating: Windows Experience Index
For the longest time, we’re all still confused about the performance of a lot of netbooks and CULV ultraportable notebooks sporting low-power CPUs. Though not very accurate, I’d say the Windows Experience Index sub-score of the CPU gives us a good perspective on the processor’s capabilities.
First, let’s look at the line-up of CPUs currently being used on netbooks and ultraportables in the market. We have four (4) from AMD and ten (10) from Intel.
You will notice that a lot of factors do affect the WEI sub-scores of the CPU. I’m looking at Instruction Set (32/64-bit) and number of cores as significant factors that affects the scores.
Likewise, the TDP (thermal design power) clearly draws the line between what CPUs are for netbooks and which ones are for CULV. Likewise, the TDPs will also give you an idea on how efficient in power consumption each CPU performs which consequently affects how long a standard battery will last on the units.
You will also notice that the Atom N450 has the highest TDP of 5.5 watts among the Atom series (yet Intel claims the platform is 20% more power efficient). This is because the graphics chip is already integrated into the CPU. The old Atom series (N280 and below) does not have that feature.
The old 945GSE/ICH7M combo has a TDP rating of 9.3W and add the 2.5 watts from the Atom CPU and you get 11.8 watts. Compare that to the new set-up with a total of 7 watts (5.5 watts for the CPU and 1.5 watts for the chipset) and you get a 41% decrease in power consumption.
Note: Most of the WEI data on the charts were personally taken by me from various netbooks and ultraportables that I’ve tried over the last months. I then compared my results to other results published online. Of the lot, the only significant discrepancy was with the WEI of the Intel Core 2 Duo Su7300 1.3GHz. My test gave me a 3.9 sub-score but others recorded a 4.0 and a 4.1 so I adjusted the figure on the chart to 4.0 (since the SU4100 has almost the same specs).