Computer requirements for real-time amp/cab sims

[Blahbbs]

I've been playing around lately with some of the VST-based amp/cab sims and I'm just wondering just how fast of a machine do you need to get the latency down to a level where you can play in real-time through these amp sims without a disruptive amount of delay for live performance

 

Granted, I've been using an M-Audio FastTrack on a older Pentium 1.7GHz laptop, so it's not the fastest machine in the world.

 

I've adjusted the input buffers, and while it was a little better, it couldn't quite cut it.

 

My Mac Mini that I also have (dual core 1.86GHz) does have much less latency, but it still doesn't seem like real-time.

 

Inquiring minds want to know...

[joeykusack]

What's the round trip latency you are getting? The settings I'm using (on more than one machine) are 128 buffer and 44.1 sample rate. I'm getting about 9ms in/out combined. I am however using a firewire interface.

[Blahbbs]

Not sure exactly. I think I had the sample rate at 44.1 and some input buffer setting sitting around 441 samples (100 b/s). Anything less than that and the signal would pop and crackle. I guess that works out to 10ms in. Out? I dunno.

I was using the Acme Bar Gig Shred suite, running under VSThost, so that might be more intense perhaps.

[joeykusack]

Well, if the fasttrack can't operate at a lower buffer (really anything above 256 is going to have some noticeable latency) Then I'd start asking some questions:

-What OS?
-You said the mac was lower, was that the same soundcard?
-Have you tried any of the "pc optimizations" for audio like moving the processor to background services?
-"aero" in vista and win7 can be troublesome
-Is vsthost the only way you can monitor vsts? Maybe if so you could try a demo of another program (like reaper which is known to run well under less powered machines) and see if the problem persists.

[WRGKMC]

No matter what you will have latency. How much will be the factor. You cant process a signal and hear it in real time.

Most use a quad core computer for the lowest latency possible. Even there you cant beat direct monitoring and using a hardware based drive setup with effects and all or micing an amp.

You can pick up one of these for about $20 on EBay and have a decent drive sound. Add an echo or reverb and you got something happening. http://www.guitarampkeyboard.com/en/behringer-gdi-21/67206

I got one the other day not thinking it would sound that great but I happily surprised to find it works as good as many of my rack preamp units for a few sounds.

[strangedogs]

GOOGLE "ASIO4ALL" - download it - install it and select it as your drivers (it has it's own control panel too accessible from within most DAW's) - it was designed for "Latency" issues and works!

[elantric]

The Lowest Latency Guitar interface i have ever experienced is the Line 6 GX

http://line6.com/podstudiogx/

Line6 has a different method than others in dealing with latency.

I would expect any line6 gear with USB and Audio to have similar specs to the ToneCore GX / PodStudio GX.

[WRGKMC]

GOOGLE "ASIO4ALL" - download it - install it and select it as your drivers (it has it's own control panel too accessible from within most DAW's) - it was designed for "Latency" issues and works!

 

 

 

It was designed for sound cards that dont have ASIO drivers and is a beta program you run at your own risk. It doesnt always work either. Many sound cards cant interface with it including many of mine. If you already have stock ASIO drivers that came with an interface its always best to use those.

 

ASIO4ALL has zero effect on latency over standard ASIO drivers designed for DAW programs. They bothe simply allow adjustment of minimum and maximum latency to match the hardware. If you have No ASIO drivers and you're using a card with no ASIO and just using the cards Duplex functions then it may well be worth trying.

 

Your computer and interface are going to determine the latency you need to set so the hardware can function properly with the software. Not the other way around. If you want lower latency you need a faster interface and a faster computer, drives etc. Optimising the computer can help improve latency too by minimising background programs running, and services running that load at boot and arent needed for recording. Check out "Black Viper" website. theres alot of tweaks there that can help as well as running latencu checkers like DPC http://www.thesycon.com/deu/latency_check.shtml

[aliensporebomb]

Interesting. On my own Mac system there's so little latency I don't really feel it.

But I'm almost always using Audio Units plugins now instead of the older VST standard.

Could be VSTHost. Macs native audio plug-in format is audio units and .VSTs are quickly becoming yesterdays news.

As a test, test some of the plug-ins in GarageBand (native audio units plugs) and check that out versus the VSTHost with the Shred amp setup.

Just to get a feel for the difference in response.

[inkblot]

Since Macs generally have a FireWire/1394 input anyway, you could try a 1394 interface. It doesn't rely on the processor because it has its own hardware controller. I don't have any noticeable latency using a FastTrack Pro though. I'm running a dual core 2.8GHz, nothing fancy or fast (its almost 3 years old).

[StompBoxLover]

 

Interesting. On my own Mac system there's so little latency I don't really feel it.

 

 

Macs have just as much latency as a PC, its all in the driver architecture/CPU power. If you don't feel it, you're used to it, that's all.

Even Macs can't get around the basic principles of physics (contrary to what 99% of Mac owners believe)

[aortizjr]

How low it can go will depend on your drivers and hardware. For ultra-low latency even your USB cable length can make a difference.

But even if you do get it down to say 64 samples, just the converters alone are going to 3-6ms of latency. All digital hardware will have this problem. So any modeler or digital effects will likely have anywhere from 6-15ms depending on their processor.

128 samples should get you to about 8-10ms which might be noticeable to some people but if they are, it is mostly psychological since that is the same as having your amp a few feet away. But that doesn't count any additional plugin latency, which some have.

For super picky guitarists, it can have an effect on the "feel" if you are playing through monitors or something. Some drummers say they can tell the bit of latency even with digital kits. Most these guys have trouble with modelers too. But even tube rectifiers have latency... so sometimes I think if you are looking for it, you will find it.

Anyway, I have noticed that Firewire interfaces tend to do better with latency and short cables. For CPU it depends on the overhead of the plugin. So it is a tough call. But for live use, it isn't a big deal.

[ashasha]

It was designed for sound cards that dont have ASIO drivers and is a beta program you run at your own risk. It doesnt always work either. Many sound cards cant interface with it including many of mine. If you already have stock ASIO drivers that came with an interface its always best to use those. ASIO4ALL has zero effect on latency over standard ASIO drivers designed for DAW programs. They bothe simply allow adjustment of minimum and maximum latency to match the hardware. If you have No ASIO drivers and you're using a card with no ASIO and just using the cards Duplex functions then it may well be worth trying. Your computer and interface are going to determine the latency you need to set so the hardware can function properly with the software. Not the other way around. If you want lower latency you need a faster interface and a faster computer, drives etc. Optimising the computer can help improve latency too by minimising background programs running, and services running that load at boot and arent needed for recording. Check out "Black Viper" website. theres alot of tweaks there that can help as well as running latencu checkers like DPC http://www.thesycon.com/deu/latency_check.shtml

 

 

I've used it with my soundcard and the latency is lower than the manufacturer's ASIO drivers. I also have issues with the manufacturer's drivers not working in Guitar Rig 3 for some reason.

 

I'll say that in my experience it isn't the system causing the latency as much as it is the crappy USB interface. It's an inherently slow interface. Firewire has always been much faster for me. I'm not talking throughput here either, I am talking about processing time through the bus. USB doesn't react as quickly.

[WRGKMC]

I use M- Audio 1010LT PCI cards which have lower latency than both USB and Firewire. Theres still latency if you're trying to process the signal tracking. If you record a single track I can get about 5ms. But as you have more tracks recorded, you have to adjust the latency higher to accomodate the additional tracks and plugins running.

If you set the cards for direct monitoring, there is no latency at all no matter how mant tracks are playing back. This is because the sound card works like a mixer and splits the signal. Half the split signal goes directly to your monitors and never gets digitized, the other half goes through the converters, routed through the bus/CPU and hard drive. Doesnt matter how long it takes to get there because you arent having to monitor it anyway.

Problem with direct monitoring is the signals dry. If you want to use plugins and monitor a processed signal, something like a dual or quad processor is the only real option to lower latency. Otherwise it sounds like you're playing through a slapback echo with the mix panned wet.

I got guitar rig 4 when I bought Sonar producer 8.5. I tried it out for 10 minuites and saw it sucked as bad as any other modeling plug I've tried and havent botherd with it since.

An analog Guitar preamp designed for recording with cabinet emulation recorded with direct monitoring selected is the only thing that comes close to an actual miced amp. But you cant steal those off the internet with illegal downloads. You can keep wishing sims sounds good but they dont come close to a good analog hardware unit.

[aliensporebomb]

I probably am used to it but it doesn't mean I don't notice it depending on what I'm doing.

 

I'll use an example: if I run an application in the background on my computer that uses heavy CPU (Seti @ Home), I definitely notice latency more.

 

With running no major apps depending on what app I'm using (such as the USB host from my VG99) it's pretty fast.

 

And apparently the smartphones of today are fast enough too because now there is amplitube for the iphone: