Does Intel's Dual-Core Atom Improve Efficiency?

Test Setup

System Hardware
Atom CPU
Intel Atom 230 (45 nm, single core, 1.6 GHz, 512 KB L2 Cache)
Intel Atom 330 (45 nm, dual core, 1.6 GHz, 2x 512 KB L2 Cache)
Core 2 CPU

Intel Core 2 Duo E8500 (45 nm, 3.16 GHz, 6 MB L2 Cache)

Intel Atom Chipset : 945GCECS 945GCT-D, Rev. 1.0 for Atom 230 / Jetway NC92-330-LF for Atom 330

Intel 945GC Chipset, ECS BIOS 080013, Jetway BIOS A02

Intel Core 2 Chipset : G31Foxconn G31MG-S, Rev. 1.0
Intel G31 Chipset, BIOS : April 29, 2008
RAM
1x 2 GB DDR2-1066 Crucial CT25664AA1067 operated at DDR2-800 (Core 2) and DDR2-533 (Atom)
HDD
Seagate Barracuda 7200.11, 500 GB
7,200 RPM, SATA/300, 32 MB cache
Blu-Ray Drive
LG GGW-H20L
Graphics
integrated 945GC and G31 graphics
Power Supplies
Fortron FSP220-60LE, 220 W


Since the Atom desktop series (230/330) supports Hyper-Threading, we decided to run the dual core with and without this feature enabled. The Atom 230 was tested with Hyper-Threading switched on at all times.

System Software&Drivers
Operating System  Microsoft Windows XP SP2
DirectX 9 Version : April 2007
Intel Chipset INF : 9.0.0.1008
Java Runtime Environment 6.0 Update 1
Application Benchmark and Settings
Benchmarks
Details
Winrar 3.80
Version 3.70 BETA 8, WinZIP Commandline Version 2.3, Compression = Best, Dictionary = 4096 KB, Benchmark : THG-Workload
Winzip 11
Version 11.2, Compression = Best, Benchmark : THG-Workload
Maxon Cinema 4D
Version : 10.008, Rendering from a scene, (Water drop at a Rose), Resolution : 1280x1024 – 8-Bit (50 frames)
Sysmark 2004 SE
Version 1.04, Office Productivity
PCMark05Version : 1.20
PCMark Benchmark
Memories Benchmark
CPU Benchmark
Graphics Benchmark
Windows Media Player 10.00.00.3646