[Datadraw-user] DataDraw L2 performance gain vs raw C

[<dat...@li...>]

Hi, all.

I compared the DataDraw version of the graph benchmark to the raw C
version in more detail.  The C version starts to suffer terribly from L2
cache misses somewhere between 10,000 and 40,000 nodes.  At 40,000
nodes, L2 cache misses take 80% of the CPU time.

		Num Nodes	Runtime	L2 miss rate
DataDraw	9,000,000	8.64s	0.4%
Raw C		40,000		40.3s	5.6%

In other words, I can allocate 225 times more memory in the DataDraw
version, yet I still don't suffer a significant L2 miss penalty, while
the raw C version chokes on L2 misses.

Regards,
Bill