The Phenom / PhenomII memory controller: ganged vs unganged mode benchmarked

Written by Gionatan Danti on . Posted in Hardware analysis

User Rating:  / 98
PoorBest 

Real world tests

Well, we now have a quite clear understand of the pros and cons of both memory controller configurations. But what about some real world, server oriented tests? I run some benchmarks for two common scenario: a web server and a database (MySQL) server.


Real wolrd tests: Apache simple test

Web server is one of the most common server role. How the ganged vs unganged question relates to this kind of workload? This test measures the performances of the system when simple, static pages are required:

 

Apache static benchmark - four concurrent client threads

With four concurrent threads, the unganged mode win by about 4%. Let's try to use 256 threads:

Apache static benchmark - 256 concurrent client threads

While the unganged mode remain the leader, its advantage now is only ~2%. This simple test probably does not load the main memory very much (here, Apache has a clear opportunity to run from the caches), and the unganged mode give us only a very small boost, if any (I consider a 2-4% difference within the margin of error).

Comments   

 
#1 Julián Fernández 2012-07-21 00:40
This was quality reading. Thanks mate.
 
 
#2 Iz 2013-01-24 23:14
Thank you for sharing these insights. I found them most useful indeed.
 
 
#3 asd 2014-03-26 19:17
Your graphs are misleading. You should ALWAYS show the full range in any graph (i.e. starting at 0 value), so the magnitude of the gains can be seen at first glance. This is statistics 101.
At least you labeled your axis.
 
 
#4 Gionatan Danti 2014-03-26 19:29
Quoting asd:
Your graphs are misleading. You should ALWAYS show the full range in any graph (i.e. starting at 0 value), so the magnitude of the gains can be seen at first glance. This is statistics 101.
At least you labeled your axis.


Yes, you are right.

When the differences are small, old OpenOffice Calc versions tend to create graphs which don't start from 0.

I realized that only after the graph were published, and I preferred to leave them unmodified.

Regards.
 
 
#5 Jay 2016-06-06 07:09
Thank you for this in-depth piece. It was the best explanation I've come across, and I've been looking for a while. :)
 
 
#6 SvenBent 2016-08-20 16:11
Ncie read through but really wish the bar graphs wasn;t made so misleading. now i have t ohave a huge focus on et he X-axis to get a indication of how big the diffrent really is.

really bad to not start your graphs at 0
 

You have no rights to post comments