AMD ATHLON 64 - Manual (Page 17)

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