Hello everybody,
I have been experimenting with some new designs on the
CMP.L2SharedNUCA.OoO simulator and I am now on the process of evaluating
my results.
I am not sure whether I got some L2 access timing parameters right, so
I would really appreciate it if you could help me get these things
straight.
a) The hit-time for a given L2 slice is given to the simulator through
the user-postload.simics spec file. Could you please confirm whether
the hit-time is evaluated as the sum of the following parameters:
flexus.set "-L2:dir_lat" "4" #
"Total latency of directory lookup" (DirLatency)
flexus.set "-L2:tag_lat" "4" #
"Total latency of tag array lookup" (TagLatency)
flexus.set "-L2:data_lat" "8" #
"Total latency of data array lookup" (DataLatency)
... so a hit for this configuration would take 4+4+8 = 16 cycles.
b) Could you give me a hint about the cost, in cycles, for each hop in
the tiled architecture? I guess that for a remote L2 hit, the overall
cost would be
<L2 hit time> + <hop time> * <number of hops>
Is the <hop time> hard-coded or can it be also defined through the
config file as a parameter of the interconnection?
Thank you in advance!
Alexandros Daglis
