Comparison between the Microprocessors

Table 24: Highest Temperature gains for all Benchmarks on all Configurations for i7-3970X

Benchmark

Configuration

Core 0 Core 1 Core 2 Core 3 Core4 Core 5

Benchm ark Average

by Cores

All Cores No HT

Bzip 19.6% 17.1% 17.4% 17.5% 15.4% 17.3% 17.4% 0%

Mcf 16.6% 13.8% 14.5% 15.9% 15.2% 15.6% 15.3% 3%

Milc 13.8% 14.7% 13.5% 14.8% 11.6% 15.6% 14% 0%

Gobmk 16% 16.6% 16.3% 16.2% 16.3% 16.8% 16.4% 0%

Zeusmp 17.1% 17.9% 16.1% 18.2% 18% 14.5% 17% 0%

Namd 18.4% 15.8% 14.5% 17.8% 17.4% 19.2% 17.1% 0%

Hmmer 16.5% 16.6% 15.8% 19.4% 16.6% 15.4% 16.7% 0%

h264ref 20.3% 16.5% 18.3% 14.1% 15.3% 19% 17.3% 0%

Core Average by

Benchmarks 17.3% 16.1% 15.8% 16.7% 15.7% 16.7%

Table 25: Highest Power Consumption gains for all Benchmarks on all Configurations for i7-3970X

 Bzip2

On i5 4200U, on all the threads an uncorrected error occurred at 90 mV of undervolting which consists of a reduction of 10.6%. On the other hand, on the i7 3970X microprocessor, the most resilient core (core 3) endured an undervolting by 14.2% and the least resilient (core 5) was undervolted by 12.8% before it crashed. As far as the all cores no HT configuration is concerned, the i5 endured an undervolting by 10% while the i7 endured an undervolting by only 8%.

 Mcf

On the ultra-low microprocessor, the most resilient core was core 1 which was undervolted by 11.2% before an uncorrected error occurred. On the other hand, the least resilient cores (cores 0, 2, 3) were undervolted by 10.6% before the system crashed. As far as the All cores no HT configuration is concerned the microprocessor was too undervolted by 10.6% when the crash occurred. Concerning the corresponding percentages for the high end microprocessor, the results are the following: The least resilient cores (cores 2, 4) were undervolted by 13.9% before the system crash whereas the most resilient core (core 5) was undervolted by 15% (205mV) before it entered the unsafe zone of operation. The All cores no HT configuration for this microprocessor endured an undervolting by 10.2%

 Milc

All the threads of the i5 4200U microprocessor crashed after the same amount of undervolting was imposed on them. More specifically, they all crashed after a voltage reduction of 10.6%. On the other hand, on the i7 3970X microprocessor, the most resilient core was again proved to be core 5, which withstood an undervolting by 13.5%

before crashing. The least resilient cores are cores 3 and four which only withstood an undervolting by 12.4% before the uncorrected error occurred. As far as the all cores no HT configuration is concerned, the 4200U microprocessor crashed after being undervolted by 10%, a percentage which is roughly the same with the 10.9% reduction percentage where the 3970X crashed.

 Namd

When examining the results of this benchmark we can see that regarding the 4200U microprocessor, cores 0, 1 and 3 were proved to be more resilient than core 2. The first three cores, endured an undervolting by 10.6% while on the other hand core 2 endured an undervolting by exactly 10% (5mV earlier) and in line with the endurance of the all cores no HT configuration. Regarding the results on 3970X microprocessor, the most resilient core was core 0 while the least resilient was core 4(13.6% and 12.45%

respectively). The all cores no HT endured less than the least resilient core by 15mV (11.3% reduction from the starting voltage).

 Hmmer

As far as 4200U is concerned, this is the benchmark that all the threads are more resilient on undervolting. All the threads endured an undervolting by 11.2% whereas the corresponding percentage about the all cores no HT configuration is 10%. On the other hand, regarding 3970X this is not the benchmark where the microprocessor endured the most. Core 0 was proved to be the most resilient for 3970X microprocessor (13.9%) while cores 1 and 5 are the least resilient (12%). The performance of the all cores no HT configuration is again poorer than the performance of the other cores and one of the poorest among all the benchmarks (9.5%).

 H264ref

Half of the threads on 4200U were proved to be as resilient as on Hmmer benchmark. That is cores 0 and 2 endured an undervolting by 11.2% whereas cores 1

and 3 only by 10.6%. The all cores no HT configuration is in line with cores 1 and 3 as far as its endurance is concerned. On the other hand, on 3970X the most resilient core for H264ref benchmark is again core 5 (13.9%) and the least resilient is core 4 (12.45%). Once again the all cores no HT configuration is the least resilient and it endured a reduction of 10.9% before an uncorrected error occurred.

 Gobmk

On 4200U the threads of the second physical core (cores 2, 3) are proved to be more resilient that the threads of the first physical core. Cores 2 and 3 withstood an undervolting by 11.2% before the system crash occurred in costrast with cores 0 and 1 where the respective percentage was 10.6%. On 3970X the most robust core is core 1 for the tests concerning Gobmk benchmark (14.2%) and the weakest core is core 3 (12.45%). Regarding the all cores no HT on the 4200U the results are in line with the weakest cores whereas on the 3970X the results are event worse as it only endured an undervolting by 9.5%).

 Zeusmp

This benchmark was proved to be one of the most favorable to the undervolting benchmarks especially on 3970X microprocessor. More specifically, in was the benchmark for which the all cores no HT configuration endured the most (12%). The most resilient cores were proves to be cores 3 and 5 by withstanding an undervolting by 14.2% whereas the least resilient core is core 0 (12.45%). Regarding 4200U the most robust cores are cores 1 and 3 (11.2%) whereas the weakest ones are cores 0 and 2 (10.6%). The all cores no HT configuration is once more in line with the weakest cores.

Benchmark

i5-4200U i7-3970X

Most Resilient Least Resilient

All Cores

No HT Most Resilient Least Resilient

All Cores No HT

Bzip2 0,1,2,3(89.3%) - 89.9% 3 (85.3%) 5 (86.8%) 91.5%

Mcf 1 (88.7%) 0,2,3 (89.3%) 89.3% 5 (84.6%) 2,4 (85.7%) 89.3%

Milc 0,1,2,3(89.3%) - 89.9% 5 (86%) 3,4 (87.1%) 88.6%

Namd 0,1,3 (89.3%) 2 (89.9%) 89.9% 0 (84.9%) 4 (87.1%) 88.2%

Hmmer 0,1,2,3(88.7%) - 89.9% 0 (85.7%) 1,5 (87.5%) 90.1%

H264ref 0,2 (88.7%) 1,3 (89.3%) 89.3% 5 (85.7%) 4 (87.1%) 88.6%

Gobmk 2,3 (88.7%) 0,1 (89.3%) 89.3% 1 (85.3%) 3 (87.1%) 90.1%

Zeusmp 1,3 (88.7%) 0,2 (89.3%) 89.3% 3,5 (85.3%) 0 (87.1%) 87.5%

Table 26: Most and Least Resilient Cores Along with their Crash Point (as percentage of starting nominal voltage) for all Benchmarks and both Microprocessors.