There has been a lot of talk lately about the latest PowerPC 970FX power figures from IBM marketing (16W at 1.6Ghz, etc), so I thought I'd compare the actual numbers (from the engineers instead of the marketroids) to the Pentium M.
Power Consumption
Clockrate (Ghz): 1.0 1.2 1.4 1.6 1.8 2.0 2.2
PPC970FX 13W 15W 18W 20W 35W 47W 56W
Pentium M 5W 10W 10W 10W 21W 21W 27W
(
mduell cries as MacNN Forums destroys his formatting)
On average, the new PPC970FX ("Power-Optimized Parts") consumes twice as much power as a Pentium M at the same clockrate. But surely our wonderful talked up G5 could just run at a lower clockrate to get the same performance. So how is the performance?
SPEC Speed
(Sum of SPECint and SPECfp at 2.2Ghz)
PPC970: 2281
Pentium M: 3129
SPEC Throughput
(Sum of SPECint_rate and SPECfp_rate at 2.2Ghz)
PPC970: 20.70
Pentium M: 32.36
On average, PowerPC 970 is two thirds as fast as the Pentium M at the same clockrate.
So PowerPC 970FX gives us two third the performance at twice the power consumption of the Pentium M. In other words, the Pentium M offers three times the performance per watt of the PPC970FX. That is what Jobs was talking about.
Yea, I can see why they're switching.
Sources:
Intel Processor Spec Finder
IBM PowerPC 970FX Data Sheet
Standard Performance Evaluation Corporation
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