I have not experienced any performance issues between HALion 5 and Cubase. My computer has a 6-Core CPU and 32 Gb of ram so I have a bit more headroom to play with. But your system should be fine, you have plenty of CPU and Memory to work with. I use to run an i5 with 8 GB ram and rarely ran into issues unless I was working with a huge project.
It may be your ASIO settings, what is your Sample Rate and Buffer setting? Running a low-low buffer size would be and issue if you have lots of things going on in your Projects (ex: many audio tracks with heavy plugins turned on). The RME Babyface is a nice card so you have options there. If your mostly working with VST’s and not direct recording instruments you can get a way with a larger buffer setting and higher latency. There are a lot of opinions out there on proper ASIO settings so see what you can find on the subject and try out a few different setups. My settings are just what works for me, I’m by no means a Pro.
It’s also good to use multiple disk drives (SSDs if possible) to cut down on the I/O traffic. Again, if your ASIO Buffer Setting is too low your computer will need to do extra I/O to keep up. Doing this on one Hard Drive is a performance drain. I have three drives, OS and Programs (like Cubase, HALion) installed on one, another for my Projects and the third drive has Samples, Sounds, Presets, etc…
Below is a list of my settings, many are just defaults.
ASIO Soundcard Settings:
Sample Rate = 44.1 kHz (I try 96 kHz every once in a while but always fall back to 44.1)
Buffer size = 96 samples (I bounce back and forth here, if my project has more External Instrument Direct Recording to audio I’ll drop it to 64 samples)
In Cubase Project Setup:
Bit Resolution = 24
In Cubase - Device Setup:
Audio Priority = Boost
Multi-Processing = On
ASIO-Gaurd = Off
Activate Steinberg Power Scheme = Off (note: I have this off because I made several similar tweaks to my computer to optimize it for DAW usage, you can have this on)
In HALion under the Options Tab:
Max Voices = 128
Max CPU = 90
Voice Fadeout = 5ms
MultiCore = OFF (important, if you have Multi Core turned on in Cubase you do not need it turned on in HALion)
Disk vs Ram balance, = One tick over to the Ram side
Max Preload = 1280 (I’ve bumped this up/down and have not had any noticeable results)
For Sample based sounds I tend to run at normal settings until I have a track set, then I crank it up to Best or Extreme (under Zone->Sample Osc) when bouncing to an Audio track/file.
Not positive if this effects performance at all so it may or may not help you but I also try to keep my HALion VST Rack instances to 8 channels/instruments Max, 4 if possible. This is just my preference to help workflow and organization. Depending on what you are trying to accomplish will dictate this, if you work with complex Multi’s or orchestral sounds you’ll want to make use of as many channels as possible.