Desktops tend to run faster than laptops; and more expensive PCs tend to run faster. But how much faster are bigger or more expensive PCs? Are all
"i7" cpus equally fast? The table below gives some answers. We tested 4 PCs:
the Yoga 2 Pro is a "convertible tablet" with fold-back
keyboard. Bought 2014.
the Dell XPS 15 is a top-end
business laptop. Bought 2013.
the "Jerie PC" is a fairly standard business desktop. Bought 2014.
the "Horridge PC" is a more expensive desktop or "workstation", using a specialized Sandy Bridge-E cpu and motherboard. Bought 2013
. Hyperthreading was disabled in the BIOS.
Note that all 4 PCs were fairly high-end: all had SSD drives and an "I7" cpu. "I5" and especially "I3" CPUs would run slower.
Two recursive-dynamic jobs were run with RunDynam with all 4 PCs:
Job1 is small. It solves a 1-region, 62-sector SAM-based model for 40 periods (120 solves).
Job2 is larger. It solves an 8-region, 58-industry, 63-commodity model for 26 periods (78 solves).
Both jobs ran base, rerun, and policy simulations for each period. RunDynam allows for either 2 or 3 simulations (sims) to be run at once: both
options were tested. You could download the tests to run on your own PC.
PC
Yoga 2 Pro
Dell XPS
Jerie Office
Horridge Home
Format
Tablet
Laptop
Desktop
Desktop
CPU
i7 4500U
i7 3632QM
i7-4770
i7-3930K
Socket
FCBGA1168
BGA1224
LGA1150
LGA2011
Speed
1.8/3.0
2.2/3.2
3.4/3.9
3.2/3.8
cores
2
4
4
6
threads
4
8
8
6
Memory
Channels
2
2
2
4
CacheMB
4
6
8
12
Job1 times
Min:sec
3 sims at once
6:34
6:49
7:08
6:41
2 sims at once
6:35
6:51
7:07
6:40
Job2 times
Minutes
3 sims at once
106
86
75
71
2 sims at once
114
104
83
88
percent saving
3-core
7
17
10
19
CPU details from Intel. Table created from Excel by the Tableizer.
Conclusions
For the smaller Job1, all PCs performed similarly, and there was little time saving by running 3 sims at once rather than 2.[This is mainly
due to some details of the way RunDynam works: it is not particularly efficient with very small models.]
For the larger Job2, differences emerge. However, the differences are not too large: at worst the little Yoga 2 Pro takes 50% longer than the
beefy workstation.
The cheaper desktop performs similarly to the workstation -- in some cases the desktop goes faster! [See the row labelled Speed.]
The final row shows the percent time saving by running 3 sims at once rather than 2 (the theoretical maximum is 26% [first policy shock was 5
years in]). Here the workstation draws ahead, probably due to its Sandy Bridge-E architecture and bigger cache (both helping with
multi-processing).