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Forum Index : Microcontroller and PC projects : CMM2 vs. PicoMite 2 Mio For-Next-Benchmark
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andreas Senior Member  Joined: 07/12/2020 Location: GermanyPosts: 187 |
2 Mio For..Next Loops CMM2:  PicoMiteVGA:  The CMM2 (480MHz) is 8.3 times faster than the PicoMiteVGA (126MHz) The CMM2 has an #include-statement which enables modular software. -andreas |
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Martin H. Guru  Joined: 04/06/2022 Location: GermanyPosts: 890 |
Messung von 2000000 For-Next - Statents ---------------------------------------- Pro Sekunde: 268592 Gesamtlaufzeit: 7.446217 > option list OPTION KEYBOARD GR OPTION CPUSPEED (KHz) 378000 OPTION SDCARD GP10, GP12, GP11, GP13 OPTION AUDIO GP6,GP7, ON PWM CHANNEL 3 with OPTION CPUSPEED 378000 ~ half as fast as cmm2 Print "Messung von 2000000 For-Next - Statents" Print "----------------------------------------" t%=Timer For f%=1 To 2000000 Next f% l= Timer-t% Print "Pro Sekunde: ";Int(2000000/(l/1000)) Print "Gesamtlaufzeit: "l /1000 a littlie faster, if I put the Next statement in the same Line as the For Statement : Messung von 2000000 For-Next - Statents ---------------------------------------- Pro Sekunde: 275513 Gesamtlaufzeit: 7.259177 but .. if I delete the Variable behind the NEXT Statement Messung von 2000000 For-Next - Statents ---------------------------------------- Pro Sekunde: 589522 Gesamtlaufzeit: 3.392575  Print "Messung von 2000000 For-Next - Statents" Print "----------------------------------------" t%=Timer For f%=1 To 2000000:Next l= Timer-t% Print "Pro Sekunde: ";Int(2000000/(l/1000)) Print "Gesamtlaufzeit: "l /1000 the question remains, how meaningful such test results are Cheers Mart!n Edited 2022-09-23 19:59 by Martin H. 'no comment |
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phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 1773 |
As an experiment to see how fast a Pico can read a pin in a FOR - NEXT loop I wrote a program to read a DHT11 temp / humidity sensor and found you can fill an array at 15uS per sample. CPUSPEED = 378000 kHz, a one digit pin number and all on one line. Every character slows it down. Here is the relevant part. 'Data format - 80uS high start pulse, 50uS low + 25uS high = 0, 50uS low + 70uS high = 1 Dim integer n ' deliver 20 mS pulse to wake up DHT11 SetPin 1,dout,oc Pin(1)=1 Pulse 1,20 Pause 19 SetPin 1,off SetPin 1,din 'Get the samples For n=0 To 329:a(n)=Pin(1):Next SetPin 1, off 'Got the samples 'for max. speed the above 'for-next' must be on one line with fewest characters Edited 2022-09-24 09:01 by phil99 |
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| andreas Senior Member Joined: 07/12/2020 Location: GermanyPosts: 187 |
Very interesting! So one can sample more than 1/15uS = 66666 samples a seconds using for-next on a pico.  -andreas |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 3496 |
And 32000000 times per seond using the PIO. PicomiteVGA PETSCII ROBOTS |
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| phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 1773 |
"And 32000000 times per second using the PIO." Yes indeed, if you have A Need for Speed. ADC and CSUB LOG also work well. Update on the For - Next. The 15uS per sample was before I added Dim Integer n That reduced it to 12.4uS per sample = 80,645 samples / second. I had assumed, wrongly, that the counter in a For - Next would automatically be an integer. That enables it to catch the 25uS pulses at 252MHz most of the time. |
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| Tinine Guru Joined: 30/03/2016 Location: United KingdomPosts: 1646 |
Because it runs from SD? Craig |
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| Tinine Guru Joined: 30/03/2016 Location: United KingdomPosts: 1646 |
Doesn't a decrementing For-Next run even faster? Craig |
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| Tinine Guru Joined: 30/03/2016 Location: United KingdomPosts: 1646 |
For decades, I have been using a high-end industrial controller (read:expensive) which consists of a real-time back-end and an extemely crude BASIC-like interpreter on the front-end. This interpreter has one data-type which is float. A literal string can be produced using a 2-character mnemonic MG"Hello World" (MG = message). I have been able to achieve all I need with this language and I never wondered about execution speed because it's never been a concern. I spent yesterday going through their documentation and the same for other similar high-end products and heck, PMBasic totally blows them out of the water. Turns out that the product I was using ten years ago which I regarded as stupidly fast, has a command execution time of 400uS  Then I moved-on to a newer model that boasted "10 times faster"...40uS...What's that, a MMBasic PIC32MX170 @40MHz? Their flagship is 11uS and that would cost me close to £4K Another big-name alternative ($4.4K Used on eBay) cautions about the limitations of their 32bits and single precision. Also runs @ ~25,000 lines/sec. MMBasic just totally freaking ROCKS!!! Craig |
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| phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 1773 |
"Doesn't a decrementing For-Next run even faster?" I must try it. Now that you have jogged my decrepit memory I may have done that in the past. |
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Plasmamac Guru Joined: 31/01/2019 Location: GermanyPosts: 501 |
@andreas where can i find the pcb from your Picomite? Plasma |
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| Martin H. Guru Joined: 04/06/2022 Location: GermanyPosts: 890 |
hmm no Print "Messung von 2000000 For-Next - Statents" Print "----------------------------------------" t%=Timer For f%=2000000 To 1 Step -1:Next l= Timer-t% Print "Pro Sekunde: ";Int(2000000/(l/1000)) Print "Gesamtlaufzeit: "l /1000 > Messung von 2000000 For-Next - Statents ---------------------------------------- Pro Sekunde: 583799 Gesamtlaufzeit: 3.425835 Cheers Mart!n 'no comment |
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| phil99 Guru Joined: 11/02/2018 Location: AustraliaPosts: 1773 |
"Doesn't a decrementing For-Next run even faster?" "hmm no" Got the same result. What little gain there might have been was offset by the extra characters STEP -1 |
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| andreas Senior Member Joined: 07/12/2020 Location: GermanyPosts: 187 |
Yes, the CMM2 has a SD-Card. But the picos can have a sd-card also. If one uses a pico as data logger, educational hardware, game machine, hobbyist thing - it makes sense to have a mass storage. #include in MMBASIC is the same as a definition/implementation module in Modula-2 or a DLL in Windows or a word in FORTH. You need it if you want to write code only once for a certain task and create more and more complex software out of simple building blocks. -andreas |
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| andreas Senior Member Joined: 07/12/2020 Location: GermanyPosts: 187 |
Hi Plasma, do you mean this one?  This is from Silicon Chip magazin July 22 VGA PicoMite ($5) or Kit ($35). -andreas |
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| andreas Senior Member Joined: 07/12/2020 Location: GermanyPosts: 187 |
Don't ask me what is going on here - this version does it in a second! Can someone verify this? I'm curious where the mistake is - but this seems to be too fast, isn't it?  ' speed.bas - Laufzeitmessung ' CLS CONST Maxloop = 2000000 ' Anzahl der Loops DIM Laufzeit AS FLOAT = 0.0 ' in Sekunden DIM a AS INTEGER = 0 ' Dummy DIM T1 AS INTEGER = 0 DIM T2 AS INTEGER = 0 ' Timer in Millisekunden PRINT "Messung von ";Maxloop%;" For-Next - Statements" PRINT "------------------------------------------" T1 = timer for a = 1 to Maxloop:next T2 = timer Laufzeit = (T2 - T1)/1000.0 PRINT "Pro Sekunde: ";INT(Maxloop/Laufzeit);" Iterationen" PRINT "Gesamtlaufzeit: ";Laufzeit;" Sekunden" save image "cmm2.bmp" The CMM2 is not "tuned" it simply runs @ 480MHz. -andreas |
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| andreas Senior Member Joined: 07/12/2020 Location: GermanyPosts: 187 |
Using the same code on the PicoMiteVGA (simply by using the same sd-card) I get improved values:  By comparing the old benchmark code to the current code there is one major difference: In the new faster code I did declare the control variable as integer before use within the for..next construct. Result: Declaring control variables before use results in huge speed-up! Example: CONST Maxloop = 10000000 DIM i AS INTEGER = 0 ' gives huge speed-up FOR i = 1 to Maxloop 'Do_something NEXT ' do not write i after NEXT It seem to be very important not to write down the control variable after the next-statement. Writing: for i = 1 to Maxloop : next is much faster than writing: for i = 1 to Maxloop : next i Doing real measurements on the cmm2 within the for..next loop:  ' bench.bas - how fast can you measure const maxmeasure = 500000 ' number of measurements cls dim mess(maxmeasure) as integer dim i as integer = 0 setpin 33,din ' digital input on pin 33 print "Start... "; t1 = timer for i = 1 to maxmeasure: mess(i) = pin(33):next diff=timer-t1 print diff;" ms for ";maxmeasure;" measurements" print (maxmeasure/diff)*1000;" measurements per second" memory save image "camac.bmp" -andreas Edited 2022-09-27 06:46 by andreas |
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