Description - phoronix/encode-mp3

LAME is an MP3 encoder licensed under the LGPL. This test measures the time required to encode a WAV file to MP3 format.

The test is single-threaded and all testing was done pinned to core 1.

Metrics (Intel) - phoronix/encode-mp3
sh - pid 15699
	On_CPU   0.125
	On_Core  1.000
	IPC      1.904
	Retire   0.493	(49.3%)
	FrontEnd 0.052	(5.2%)
	Spec     0.103	(10.3%)
	Backend  0.351	(35.1%)
	Elapsed  32.67
	Procs    3
	Maxrss   10K
	Minflt   784
	Majflt   0
	Inblock  0
	Oublock  8
	Msgsnd   0
	Msgrcv   0
	Nsignals 0
	Nvcsw    18	(4.5%)
	Nivcsw   380
	Utime    32.639124
	Stime    0.024001
	Start    236604.99
	Finish   236637.66

The test is 100% on a single core. Overall IPC is higher, with a reasonable amount of backend stalls and some bad speculation.

Metrics (AMD) - phoronix/encode-mp3
sh - pid 18520
	On_CPU   0.062
	On_Core  0.999
	IPC      1.724
	FrontCyc 0.718	(71.8%)
	BackCyc  0.096	(9.6%)
	Elapsed  37.51
	Procs    3
	Maxrss   10K
	Minflt   786
	Majflt   0
	Inblock  0
	Oublock  8
	Msgsnd   0
	Msgrcv   0
	Nsignals 0
	Nvcsw    18	(0.4%)
	Nivcsw   4530
	Utime    37.473822
	Stime    0.012338
	Start    246638.97
	Finish   246676.48

IPC on AMD platforms just slightly lower.

Process Tree - phoronix/encode-mp3
Process Tree
    15699) sh
      15700) lame
        15701) lame

Overall process tree is simple, one process running for ~30 seconds.


Shows the process being scheduled ~100% of the time.


Fairly consistent IPC all along.


Backend stalls are largest issue preventing higher retirement rate.

Next steps: Understand nature of backend stalls.