[TK.]

determine the truth about your MIDI interface:

;
; MIDI Performance Measuring Application
;
; This is some kind of benchmark which helps to evaluate the performance
; of your MIDI interface (and computer)
;
; To get the test running you have to create a MIDI feedback loop.
;
; Examples:
;    Direct Feedback:   CORE1 OUT -> CORE1 IN
;    Merger Feedback:   CORE1 OUT -> CORE2 IN -> CORE2 OUT -> CORE1 IN
;    Computer Feedback: CORE1 OUT -> PC MIDI IN -> MIDI-Ox -> PC MIDI OUT -> CORE1 IN
;
; A MIDI controller event will be sent and should be received "immediately"
; is measured with timer3, prescaler 1:8 - this means, that the counter 
; result has to be multiplied by 8 and 100 nS (@40 MHz) to get the
; absolute delay
;
; Note that the delay is always greater than 960 uS, since this is the
; initial transfer time of a controller event
;
; The current, minimal and maximum result will be print on LCD
; To determine the jitter, calculate: (max-min) / 2
;
; IMPORTANT: remove the feedback loop before uploading a new application,
; otherwise MIOS will wait endless before rebooting the core!!!
;
; And here the results:
; 
;    o direct feedback:
;      Min: 1218, Max:  1262  ->  0.97 mS /  1.01 mS  ->  +/- 0.02 mS Jitter
; 
;    o merger feedback (2 cores):
;      Min: 1664, Max:  1735  ->  1.33 mS /  1.38 mS  ->  +/- 0.03 mS Jitter
; 
;    o RME Hammerfall DSP/Multiface, WinXP, Feedback via MIDI-Ox
;      Min: 2497, Max:  2599  ->  2.00 mS /  2.07 mS  ->  +/- 0.04 mS Jitter
;
;    o RME Hammerfall DSP/Multiface, WinXP, Feedback via Logic Audio
;      Min: 2565, Max:  3820  ->  2.05 mS /  3.05 mS  ->  +/- 0.50 mS Jitter
;
;    o MBHP_USB (WinXP Legacy Driver), Feedback via MIDI-Ox
;      Min: 3320, Max:  4555  ->  2.66 mS /  3.64 mS  ->  +/- 0.50 mS Jitter
;
;    o MBHP_USB (WinXP Legacy Driver), Feedback via Logic Audio
;      Min: 3510, Max:  6291  ->  2.81 mS /  5.03 mS  ->  +/- 1.11 mS Jitter
;
;    o MIDIsport 2x2, WinXP, Feedback via MIDI-Ox
;      Min: 6219, Max:  9960  ->  4.98 mS /  7.97 mS  ->  +/- 1.5 mS Jitter
;
;    o MIDIsport 2x2, WinXP, Feedback via Logic Audio
;      Min: 7608, Max: 13446  ->  6.08 mS / 10.76 mS  ->  +/- 2.3 mS Jitter

Add your results here! :)

Best Regards, Thorsten.

[adamjking]

My Results:

Direct Feedback (Note: I had to make the direct feedback loop after MIOS had booted, or else it wouldn't boot - is this normal?)
Min: 1218, Max:  1257  ->  0.97 mS /  1.00 mS  ->  +/- 0.015 mS Jitter

SBLive 5.1 Platinum (via Joystick Port adaptor), Win98, Feedback via MIDI-Ox
Min: 2567, Max:  2725  ->  2.05 mS /  2.2 mS  ->  +/- 0.075 mS Jitter

SBLive 5.1 Platinum (via LiveDrive MIDI ports), Win98, Feedback via MIDI-Ox
Min: 3058, Max:  3188  ->  2.46 mS /  2.55 mS  ->  +/- 0.045 mS Jitter

SBLive 5.1 Platinum (via Joystick Port adaptor), RedHat Linux 8.0 (ALSA 0.9.6
drivers, 2.4.22 kernel w/low latency patches), Feedback via qjackctl
Min: 2090, Max:  2533  ->  1.67 mS /  2.02 mS  ->  +/- 0.175 mS Jitter

[TK.]

Thanks for the values! :)

Quote

(Note: I had to make the direct feedback loop after MIOS had booted, or else it wouldn't boot - is this normal?)

yes - see following note:

; IMPORTANT: remove the feedback loop before uploading a new application, 
; otherwise MIOS will wait endless before rebooting the core!!! 

Best Regards, Thorsten.

[chriss]

These are my results.
The Win machine is a AMD PII/K6, 400Mhz, 64MB, USB1.1
The Mac is a Ibook G4, 933Mhz, 640MB, USB2.0


MBHP_USB, WinXP, Feedback via MIDI-Ox  
Min: 4193, Max:  6278  ->  3.35 mS /  5.02 mS  ->  +/- 0.84 mS Jitter  
 
MBHP_USB, WinXP, Feedback via Logic 5.3
Min: 4677, Max:  8072  ->  3.74 mS /  6.46 mS  ->  +/- 1.36 mS Jitter  
 
MBHP_USB, Mac OSX, Feedback via Logic Hit Kit 
Min: 3669, Max:  5152  ->  2.93 mS /  4.12 mS  ->  +/- 0.59 mS Jitter

Chriss

[lylehaze]

And now for new data on an old topic..

I have loaded and run the benchmark application on my
MidiBox core. V1_9B, 18F452 @ 40Mhz

Since my interface and OS were not benchmarked previously,
I thought some might find it interesting.

I'm running an Edirol UM-880 USB midi interface, which offers
"HDMR" (Hardware Direct MIDI Routing). I always wanted to know how
fast it really was.

Running Core 1_9B, I got

1235  to  1247
0.99ms    1.0ms
Jitter .005

Pretty good stuff.

Then, patching the MIDI through the 880 to my computer,
using CAMD library and "MidiThru" at priority 0,

2464  to  4218
1.97ms    3.37ms
Jitter 0.7ms

This is running through OS4 on an AmigaOne computer.

Looks like it's at least comparable to some of the other
types of computers.

LyleHaze

[Ruff-G]

what is the name of the application of your tests?

regards,
ruff-g

[TK.]

midi_benchmark.zip (-> MIOS upload page)

Best Regards, Thorsten.

[Ruff-G]

thanks Thorsten for your help