- Joined
- Mar 7, 2008
To have a consistent clock on the 12100F I turned turbo off, so it ran at base clock of 3.3 GHz. I also ran it with and without HT, as well as observing the power consumption. With that I hope to get some insight on how much perf HT could bring, at what power cost. When introduced it was claimed to give a bigger perf increase than power draw increase. Let's see if that happens. Note the 12100F system has a single channel dual rank 3200 ram module as I can't physically fit a 2nd due to cooler getting in the way. I have not checked if any of these tests may be limited from this.
Cinebench R15: HT gave a 40% increase in score for a 19% increase in power. The perf increase is bigger than I expected, given older CPUs (Zen 2/Skylake family and older) were around the 30% mark from HT.
Y-cruncher: 13% increase from HT at both 25m and 1b. I saw 14% increase in power 1b. The 25m test was too short for me to look at the power.
POV-Ray: 18% increase in perf for 17% increase in power.
Linpack Xtreme: 1.5% increase in throughput for no change in power. Margin of error?
Prime95 128k throughput: No change in perf for 11% increase in power draw. This workload is known not to benefit from HT, and the overhead of it even being there works against it. Running system HT on but not using the threads lowers the power usage without impacting performance.
7-Zip: 17% faster compression, 47% faster decompression, 16% more power draw.
Results are all over the place. Cinebench R15 and 7-Zip decompression see a great benefit from HT, and improves perf/W. POV-Ray, Y-Cruncher and 7-Zip compression see an improvement in performance but no significant change in perf/W. Linpack Xtreme and Prime95 both don't see a change in perf, with P95 seeing a big drop to perf/W with HT.
Actual power usage of each workload (rounded) with HT on:
Cinebench R15: 35W
Y-cruncher: 40W
POV-Ray: 35W
Linpack Xtreme: 37W
7-Zip: 29W
Prime95: 45W (41W without HT)
This is why I refer to Cinebench R15 as a "light" workload, and Prime95 to be a "heavy" one. If instead you run a fixed power limit instead of fixed clock, then the heavier workloads will end up with the CPU at a lower clock than light workloads.
Note I put this in Intel section since I tested on a 12100F. I wouldn't be surprised to see similar scaling on AMD.
Cinebench R15: HT gave a 40% increase in score for a 19% increase in power. The perf increase is bigger than I expected, given older CPUs (Zen 2/Skylake family and older) were around the 30% mark from HT.
Y-cruncher: 13% increase from HT at both 25m and 1b. I saw 14% increase in power 1b. The 25m test was too short for me to look at the power.
POV-Ray: 18% increase in perf for 17% increase in power.
Linpack Xtreme: 1.5% increase in throughput for no change in power. Margin of error?
Prime95 128k throughput: No change in perf for 11% increase in power draw. This workload is known not to benefit from HT, and the overhead of it even being there works against it. Running system HT on but not using the threads lowers the power usage without impacting performance.
7-Zip: 17% faster compression, 47% faster decompression, 16% more power draw.
Results are all over the place. Cinebench R15 and 7-Zip decompression see a great benefit from HT, and improves perf/W. POV-Ray, Y-Cruncher and 7-Zip compression see an improvement in performance but no significant change in perf/W. Linpack Xtreme and Prime95 both don't see a change in perf, with P95 seeing a big drop to perf/W with HT.
Actual power usage of each workload (rounded) with HT on:
Cinebench R15: 35W
Y-cruncher: 40W
POV-Ray: 35W
Linpack Xtreme: 37W
7-Zip: 29W
Prime95: 45W (41W without HT)
This is why I refer to Cinebench R15 as a "light" workload, and Prime95 to be a "heavy" one. If instead you run a fixed power limit instead of fixed clock, then the heavier workloads will end up with the CPU at a lower clock than light workloads.
Note I put this in Intel section since I tested on a 12100F. I wouldn't be surprised to see similar scaling on AMD.
