New Multi-Threaded Pi Program - Faster than SuperPi and PiFast

[Chumbucket843]

here a core 2 quad at stock. One of the reasons for poor scaling is core 2's cache. it has no shared l3 so the cores only get 2mb l2 each.

[poke349]

here a core 2 quad at stock. One of the reasons for poor scaling is core 2's cache. it has no shared l3 so the cores only get 2mb l2 each.

Those were done using processor affinity right? Because there's no 3-thread mode, and 2-thread mode will use up to 4 threads.

Also I think a big reason is that the program was tuned with 3MB of cache per thread. So massive cache spilling on a bandwidth-limited system will have major penalties.


Here's Q9400 scaling... Also very bad. I also don't know what was causing all of the variation in the benchmarks.

Main Page




Here's some very old results with version 0.2.1 on my workstation:
Scaling seems to hit a wall at 7x. I'm almost certain it's the memory bandwidth.

Main Page


I need to integrate a bulk-bench option that will generate the data for these graphs without having to do each benchmark by hand.

I already have an automated benchmark add-on (hence how I did all these runs), but it has no interface yet - all options are set in the source code and I have to recompile it everytime I change a setting.