AMD athlon 64 User Manual

Page of 48
Chapter 2
Experimental Setup
17
Performance Guidelines for AMD Athlon™ 64 and AMD Opteron™
ccNUMA Multiprocessor Systems
40555
Rev. 3.00
June 2006
characterization of the resource behavior in the system. These recommendations, coupled with these 
interesting cases, provide an understanding of the low-level behavior of the system, which is crucial 
to the analysis of larger real-world workloads.
2.3
Reading and Interpreting Test Graphs
Figure 3 below shows one of the graphs that will be discussed in detail later.
Figure 3.
Write-Only Thread Running on Node 0, Accessing Data from 0, 1 and 2 
Hops Away on an Idle System
2.3.1
X-Axis Display
The X-axis displays the various thread and memory placement combinations to be compared. Each 
case shows the following information for the thread, in the order listed:
The node and core on which the thread is run.
Whether accesses are read-only or write-only.
The node on whose physical memory the data accessed by the thread resides.
In Figure 3 above, the four bars correspond to the following thread combinations:
0.0.w.0—Thread running on node 0/core0 does write-only accesses to memory resident on node 0.
0.0.w.1—Thread running on node 0/core0 does write-only accesses to memory resident on node 1.
0.0.w.2—Thread running on node 0/core0 does write-only accesses to memory resident on node 2.
0.0.w.3—Thread running on node 0/core0 does write-only accesses to memory resident on node 3.
 
T im e   fo r   w r ite
113 %
1 27 %
12 9%
1 4 9 %
0
0 .2
0 .4
0 .6
0 .8
1
1 .2
1 .4
1 .6
1 .8
0 .0 .w .0
0 .0 .w .1
0 .0 .w .2
0 .0 .w .3
0  Ho p
1  Ho p
1  H o p
2   Ho p