[Chart] FM3 Block CPU Usage Estimates

[Greg Ferguson]

@chris Is this still accurate and dependable or have things improved/changed in the last year and change? I also noticed that shunts weren't listed, yet I know they use up a little DSP, which is why I always try to condense my presets as much as possible. Just curious.

Thanks for this!

It's missing new reverb and drive models and the Looper. From my experiments the Looper block uses up to 5%. From quickly watching the Asylum Hall Reverb model on High, on the FM3 with Cygnus v4 I show 29% usage. The Ultra-High setting took it up another 3-ish%.

 

[MKB99]

The base cpu @11 %
Is this used at all times as default by the System?
So we lose 11% straight off the Bat?

Always whatever is actually loaded.

Yes. A blank layout uses 11% and the approximate usable limit is 80%. These numbers on their own don’t really mean much. Actually using and adding blocks on the unit brings it all together.

The FM3 just launched. We will probably see improvements to all of this over time. Majority of blocks have had decreased CPU usage during testing so it can probably get even better from here.

I just checked CPU usage on my FM3 (firmware v5.02)with a completely blank preset, and it measures as 13.8%. Is there a list or suggestions on any IO or other configurations that can be changed to get back down to 11%? I tried defeating output EQ, but the CPU save was negligible.

 

[Ugly Bunny]

I just checked CPU usage on my FM3 (firmware v5.02)with a completely blank preset, and it measures as 13.8%. Is there a list or suggestions on any IO or other configurations that can be changed to get back down to 11%? I tried defeating output EQ, but the CPU save was negligible.

This is a very old list/chart. Don't take it as gospel; it'll change slightly with every FW update. No, there's nothing anyone other than FAS can do to reduce CPU usage on either a blank preset or on a full preset (other than simple tricks like reducing reverb quality, using only one IR, that sort of thing).

 

[JRod4928]

It's CPU-gate.

 

[MKB99]

This is a very old list/chart. Don't take it as gospel; it'll change slightly with every FW update. No, there's nothing anyone other than FAS can do to reduce CPU usage on either a blank preset or on a full preset (other than simple tricks like reducing reverb quality, using only one IR, that sort of thing).

Thanks for the reply. Even if the list is old, it is still very useful as in my tests the numbers are still close. The only real outlier was the CPU with a blank preset, and I assumed there might be a global setting of some kind that could eat some CPU.

The FM3 is full of little details that are not obvious but can help greatly with its use, and the chart pointed out a few of those. One is to stay away from reverb if delays will do the job if you want lots of effects.

 

[adagosto]

Please forgive the redundancy in this question…I’m getting close to pulling the trigger on an FM3, but I’m a bit more concerned about DSP limitations now than that I’ve watched a few videos.

My baseline preset would look like this:
Input…noise gate…overdrive pedal…boost…EQ…amp/cab…TriChorus…Delay…Reverb.

I understand there are ways to optimize this, but straight out of the box, can the FM3 even do this at reasonably high quality? Everything doesn’t need to be the best but maybe some be very high and other be normal.

Thanks for your help understanding the DSP limitation reality or not…

 

[skolacki]

Please forgive the redundancy in this question…I’m getting close to pulling the trigger on an FM3, but I’m a bit more concerned about DSP limitations now than that I’ve watched a few videos.

My baseline preset would look like this:
Input…noise gate…overdrive pedal…boost…EQ…amp/cab…TriChorus…Delay…Reverb.

I understand there are ways to optimize this, but straight out of the box, can the FM3 even do this at reasonably high quality? Everything doesn’t need to be the best but maybe some be very high and other be normal.

Thanks for your help understanding the DSP limitation reality or not…

I think it's easily doable but reverb may need to be a lower quality setting. Low quality reverb is all I use and it sounds fine. That's the reality of the FM3. My typical preset has a drive, amp, cab, plex, delay, reverb, and maybe a filter or trem/pan block or chorus or rotary. I use Dynacabs which is the best cpu option. Or 2 standard length IR's. Boost can be a modifier on the existing output block or the amp boost included in the amp block. The input block includes a noise gate already. I'm on the original pre turbo FM3 and have a FC6. So if you buy new then you have another 10% so you might be able to use higher quality reverb. It really depends on switches and if you're ok with just 3. I need more switches so there's the FC6. If you want more switches the FM9 is a no brainer. Cpu is a juggling act for all platforms, I'll read comments from FM9 and Axe users bitching about cpu and I gotta laugh. I'm totally happy with the FM3. No plans on upgrading unless my FM3 dies or the next gen comes out. The FM3 is a lot of bang for the buck but keep in mind it is the bottom level unit. That said, it does a lot and sounds great. Best guitar toy ever for me.

Edit: I tried high quality reverb. It wasn’t that bad of a hit. So you can do what you noted in your post on the turbo easily.

 

[fcs101]

Please forgive the redundancy in this question…I’m getting close to pulling the trigger on an FM3, but I’m a bit more concerned about DSP limitations now than that I’ve watched a few videos.

My baseline preset would look like this:
Input…noise gate…overdrive pedal…boost…EQ…amp/cab…TriChorus…Delay…Reverb.

I understand there are ways to optimize this, but straight out of the box, can the FM3 even do this at reasonably high quality? Everything doesn’t need to be the best but maybe some be very high and other be normal.

Thanks for your help understanding the DSP limitation reality or not…

I'd direct you to this calculator:

https://forum.fractalaudio.com/threads/made-a-dsp-calculator-for-fm3-turbo.219493/

It's probably more current than the chart.

Couple of notes:

1. The noise gate is incorporated into the Input block, so that's not its own thing.

2. The 3 will handle two Drive blocks, but I'm not sure you'd need the boost, as you may just be able to use a second amp channel for that.

3. I'm not sure you'd need the EQ. There are EQs within the amp and cab.

I can't see any problem with what you're proposing though. Lots of presets I use are much more complicated. I am assuming your talking FM3T.

 

[frikkie5000]

You'll be fine.

As already pointed out, you don't need a dedicated gate as the one in the input block is great.

Regarding tye reverbs, I personally found even economy to be amazing. You can hardly tell the difference when A/B'ing the settings and in a mix even you wouldn't ve able to tell the difference when playing. No chance of the audience being able to.

The extra DSP usage of the higher settings are completely not worth the tradeoff. That being said, with your simple effects chain you'd be able to use the majority of the reverbs on a higher setting anyway.

For your use case, if you'd be willing to use ultra-res IRs and economy reverb, you'd only be hitting about 50-70% of the limit of 85. Most of the serious DSP hogs are the very esoteric reverbs and plex delays. For bog standard chains using standard analog or digital delays, plate/spring reverbs, etc. you won't come even close to the DSP limit even if you add a bunch of stuff

 

[adagosto]

You guys are amazing. Thank you so much for taking the time on my questions. Great to know. I will pull the trigger soon on this. I was on the FM3 FM9 fence. I really would prefer the 3. I think I’m good.

 

[fcs101]

You guys are amazing. Thank you so much for taking the time on my questions. Great to know. I will pull the trigger soon on this. I was on the FM3 FM9 fence. I really would prefer the 3. I think I’m good.

I just constructed a generic template as such:

Input--Drive--Drive--Amp--Cab--Chorus(Tri Chorus)--Delay--Reverb--Output

The CPU sits at 53.3% on the FM3T. I forgot to add the EQ, but that is minimal impact (and I doubt you'll need it). Point is that you'll have plenty of room to maneuver.

Don't let the negative comments about CPU concern you. I haven't had any issues on the 3T. You never know what some people have going on in their presets. The 3 is a beast and is more than capable for what you want.

 

[chris]

Please forgive the redundancy in this question…I’m getting close to pulling the trigger on an FM3, but I’m a bit more concerned about DSP limitations now than that I’ve watched a few videos.

My baseline preset would look like this:
Input…noise gate…overdrive pedal…boost…EQ…amp/cab…TriChorus…Delay…Reverb.

I understand there are ways to optimize this, but straight out of the box, can the FM3 even do this at reasonably high quality? Everything doesn’t need to be the best but maybe some be very high and other be normal.

Thanks for your help understanding the DSP limitation reality or not…

Everything is already at a high quality. The reverbs set to a “lower quality” are still high quality, honestly.

I’ve bought and gigged a few other modern units recently just out of curiosity and… let’s just say the FM3 still has the best sound, feel, and adjustability in my opinion.

I still cannot hear an appreciable difference in setting every option to its highest quality (cabs, reverb, etc) for live playing, even solo or duo acoustics where a band isn’t covering things up. Perhaps for recording, keeping presets lean and bumping up those options makes sense, then re amping or adding effects later if they didn’t fit - but you can do that for recording.

I can hear a difference of course, but nothing that affects my live performance. Could just be me.

Adjusting those options to “lower quality” settings does not mean you suddenly have a reverb pedal sound from the 1940s technology.

 

[MayPRS]

You guys are amazing. Thank you so much for taking the time on my questions. Great to know. I will pull the trigger soon on this. I was on the FM3 FM9 fence. I really would prefer the 3. I think I’m good.

I gig the FM3 reguralrly. My presets have drive, chorus, amp, ultra-res cab, delays and pitch. CPU sits at 53%. The FM3 (unless you REALLY need dual amp setup) is the perfect form factor IMHO.