System Power Draw Tests
AMD's latest Phenom II CPUs are built on a 45nm
manufacturing process. It will be interesting to see if this, and
re-architecting of the Phenom II's microprocessor reduce power draw
significantly compared to Intel's Core 2 Duo and Core 2 Quad CPUs.
As always, before any power measurements are taken the CPU power saving and
clock speed throttling technologies like Cool 'n' Quiet, EIST (speedstep) and
C1E power states are disabled. PCSTATS then set about stressing each core of the
processor one by one, until all cores were loaded.
For this we used Stress
Prime (SP2004). The total system
power consumption, measured in Watts, is monitored with an Extech Power Analyzer
Datalogger (model 380803). The power meter is located between the main 120AC
supply and the PC's power supply so it measures the entire computer system, the
difference between CPU loaded and unloaded states is the key value to pay
attention to.
* DDR2 based system, ** DDR3 based PC system.
Running three Phenom II cores in DDR2 memory mode draws a bit more power than PCSTATS likes to see,
but fortunately a switch to a socket AM3 motherboard and DDR3 memory mode reduced
power draw signficantly in idle mode, bringing the AMD Phenom II X3 720 Black Edition in line with the
Core 2 Duo E8400 processor.
| Total System
Stressed Power Draw - All Cores/Threads |
| Processor |
Total System Power Draw (All Cores) |
| Intel Pentium 4 540 |
   223 Watts |
| Intel Pentium D 840 (2 Core ) |
240 Watts |
| Intel Pentium D 940 (2 Core Load) |
253 Watts |
| Intel Core 2 Duo E6600 (2 Core Load) |
156 Watts |
| Intel Core 2 Duo E6750 (2 Core Load) |
163 Watts |
| Intel Core 2 Duo E8400 (2 Core Load) |
158 Watts |
| Intel Core i7 920 (8 Thread Load) |
213
Watts |
| AMD Sempron 3600+ |
   148 Watts |
| AMD Athlon64 4000+ |
172 Watts |
| AMD Athlon64 FX-60 (2 Core Load) |
196 Watts |
| AMD Athlon64 X2 4800+ (2 Core Load) |
173 Watts |
| AMD Athlon64 X2 5000+ (2 Core Load) |
207 Watts |
| AMD Athlon64 FX-62 (2 Core Load) |
235 Watts |
| AMD Athlon II X2 250 (2 Core Load) |
163
Watts |
| AMD Phenom II X2 550 (2 Core Load) |
181
Watts |
 AMD Phenom II X3 720* (1 Core) |
   182
Watts |
| AMD Phenom II X3 720** (1
Core) |
157
Watts |
| AMD Phenom II X3 720* (2 Core) |
196
Watts |
| AMD Phenom II X3 720** (2
Core) |
176
Watts |
| AMD Phenom II X3 720* (3 Core) |
213
Watts |
| AMD Phenom II X3 720** (3
Core) |
190
Watts |
* DDR2 based system, ** DDR3 based PC system.
When stressed the power consumption of the Phenom II AMD
Phenom II X3 720 Black Edition was 190W in DDR3 mode
, and broke the 200W barrier when using higher-wattage DDR2 memory. It seems
like AMD doesn't have a lot of headroom with this generation of processors, we
may not see Phenom II processors clocked higher than 3.4-3.6GHz or
so.
|
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