I have decided to have a look a LP EQ and LP MB but adding them in seems to elevate my CPU quite a lot. Why I would bother with LP EQ I don't know the Pro Channel EQ does a good job. But even adding the LP MB (multiband compressor) on my master bus lifts up the CPU then if I also put it on a track then the CPU lifts and leaves me with the odd stutter. Using Reapers multiband compressor ReaXComp in the same way all is fine.

I have an I7-4770 CPU with 16 gig of Ram so it should cope.

they're linear phase so need some look ahead. you can increase buffers and not use them in real time and you'll be fine

Thanks I'll have a look

You can also use non linear phase mode in expert settings on both of these plugins as well.

Makes a big difference when I used them as they were designed to be used. I was using them in the Master track with several other tracks. If I export the mix and bring the mix back as one track the LP EQ and LP MB work a treat. When I look about this appears to be the way they were designed to be used as a mastering tool.

Most Lp eq's are meant to be used in the mixing stage. They typically have very little to no flavor.

The Curve EQ's in the PC are designed to have some flavor/character. You have four choices.

In addition to using them in non-linear mode in the "draft" stages of a project, you can also use a low precision setting. True linear-phase processors are indeed CPU-intensive.
 
 

I always have them in my master bus FX bin when starting or adding to a project.  I usually use LP EQ and LP Multiband comp.  I follow that up with Voxengo Elephant and SPAN.  When tracking, I just bypass the master FX bin.  Then I can play guitar, track bass or vocals...or whatever with essentially no latency.  When mixing, I turn the master bus FX bin back on.  I just master in the project.  I master to about a K-8 level and use Voxengo Span to look at the spectrum of the song.  Of course, I use my ears as well :)
 

At least for me, most CPU intensive part of these plug-ins is GUI... without GUI open, even with the slowest settings, they do not consume much. Tried with OpenGL and disabled, not a big difference (I have GTX1050, it normally has no problems even with more complicated graphics).
I agree, in LP mode these plug-ins are unusable on Sonar/CbB tracks... but work fine on Reaper tracks

azslow3
I agree, in LP mode these plug-ins are unusable on Sonar/CbB tracks... but work fine on Reaper tracks

Why do you think that is? Different audio engine? Different way of handling delay compensation (I assume Reaper does automatic delay compensation)?