This is something I should already know but I have never had need thusfar in all my years using Sonar to have to use live input monitoring as I lay down a track. I have always just used line 6 POD products for all my guitar amp and effect tones. I've never used anything like Guitar Rig or Amp Farm ... any of those things ...
 
So, when I recently tried to run a live convolution reverb plugin (perfect space) with a speaker cabinet impulse response loaded and got a nasty half second delay in my guitar tone I had no idea how to address the problem. I gather you have to bring your recording and playback buffer sizes way down during tracking, but when I adjusted them from 1024 each to 64 ... and even 32 and it had no effect on this buffering latency, I was really scratching my head.
 
There is also a "ASIO Buffer settings" area on my soundcard's MixControl (Focusrite Scarlett 18i20) software that has a range of settings between 1.0 ms and 20 ms. How are those related to the recording and playback buffers in the preferences panel?
 
I am obviously doing something boneheaded, I just can't tell what it is. What do I need to do to get a latency acceptable enough to allow me to lay down live guitar tracks without this latency? Is it even possible to play live with plugins going with a laptop like mine? I am a clueless goon on this one ...
 
Laptop specs are as follows: Sonar X3 Producer 64-Bit, Focusrite Scarlett 18i20 Soundcard (USB), Dell Inspiron 5748, Intel i-7 processor 2.0 GHz, 8 MB Ram.

Some CPU-intensive plug-ins add significant latency, and congratulations - convolution reverb is one of the most CPU-intensive ones. I'd recommend using a traditional reverb since you're not recording the processed sound, just the dry guitar signal. Then, use the CPU-intensive plug-ins during mixdown, where you won't mind more latency.

There is also a "ASIO Buffer settings" area on my soundcard's MixControl (Focusrite Scarlett 18i20) software that has a range of settings between 1.0 ms and 20 ms. How are those related to the recording and playback buffers in the preferences panel?
 
Focusrite uses a different system than normal with those numbers. It's been a while but I do believe 10 ms is the same as 256ms. This is the "safe" default. 
I run mine at 7ms (128?)  which is stable. I can go lower on some simple projects but at the risk of a dropout.  
The Mix Control menu is where you set your ASIO buffers. You have to see how low you can go before your system becomes unstable. Your laptop is not very powerful so I doubt your going to be able to set it very low. 
 
Focusrite scarlett interfaces are not top performers with RTL and you'll see what your is here. 
 

Thanks guys for that info. I have a slower computer but also am sampling at 88.2 instead of 44.1 ... that might also contribute to the sucky performance. I see people on YouTube all the time that are able to run plugins live ... I know it's possible ...
 
A guy at Sweetwater recommended this free cab plugin that I think I'm going to try out and see if that performs any better with the cabinet sims: https://lepouplugins.blogspot.com.ar/
 
I actually was trying to record whilst input monitoring the plugin live, but could never get it lower than about a quarter of a second ... way too much to lose yourself in a recording. I guess I could do like Craig was saying and record without the feel of the cab and just add it in later during mixdown ... but so much of the appeal of using a load box with cab sims is that it feels like I am playing through my Super Reverb live. A lot of that is that EQ curve of the cab sim ... bummer.
 
So Cactus Music, you said "The Mix Control menu is where you set your ASIO buffers."
 
Does this mean you leave the playback and recording numbers alone and only change buffer settings in MixControl? This might explain why altering those numbers had no effect on my latency.
 
 

Try TH2 producer. Their IR works without a noticeable latency. Start off with one of the supplied IRs and get your system tuned. I record with amp sims and fx and monitor thru input echo. My DAW is beefier, but my laptop is just a bit faster.
 
TH2 producer opened with preset 001 factory, if that's the case for you delete the amp and the reverb fx and change the cabinet to IR. 

If I have to pay that much for a plugin I think I would just rather spend the money on something like the Palmer PD103 or maybe even the Two Notes Torpedo Live ... something that has everything in the hardware box. I really want the feel of the cab as I lay down the track so apparently this is the best, yet most pricey option.
 
Anybody know of anything else that lets you load third party IRs and play through it live?

Anybody know of any free plugins that let you run IRs?
 

Not free, but this is what I'll use when not using an amp sims builtin.
 
http://www.redwirez.com/mixir2.jsp
 

Features at a Glance

• Efficient, no-nonsense, drag-and-drop IR browser

• Zero latency, so it adds no delay to the signal

• Run one IR or 30 with the same unmatched performance

• Efficient, optimized convolution engine with low CPU usage let's you run more plug-ins.

• Powerful internal routing allows you to mix IRs without messing with busses and sends

• Mix IRs in stereo with pan controls

• Upload, download, share and rate presets on redwirez.com

• 32-bit and 64-bit Windows VST

• 32-bit and 64-bit OSX VST and AU

• RTAS for Pro Tools 9, 10 Windows/OSX

• AAX Native 64-bit for Pro Tools 11

• No authorization, activation or licensing scheme to get in the way

• Neve 1073 EQ impulse responses included

• Buy it solo, or get it free with the purchase of the complete BIGBox library.

It does what it does very well.

That does look pretty cool. And at that price, it may as well be free.
 
I was asking for something free to try an experiment to see if just a different app may have a positive effect on latency.
 
Here's what I am looking at now. I know, I was just on here asking for free, and now I'm about to drop over a grand ... but this UAW OX Box is way cool.
 
It has built into it the very cabinets that I need ... the 4x10 Bassman / Super Reverb thing, the 1x12 Deluxe thing ... a champ ... I am in heaven. It also has room settings for a bigger distant miking sound. And it lets you run different impedance amps.
 
https://www.sweetwater.com/store/detail/OX--universal-audio-ox-reactive-amp-attenuator-with-speaker-modeling
 
 

scottcmusic
If I have to pay that much for a plugin I think I would just rather spend the money on something like the Palmer PD103 or maybe even the Two Notes Torpedo Live ... something that has everything in the hardware box. I really want the feel of the cab as I lay down the track so apparently this is the best, yet most pricey option.
 

The OP says you have Sonar X3 Producer - that should have come with TH2 producer.