Glitchy audio when scissors tool is moved around project

I wonder if anyone can help me.

I’ve had no problems whatsoever with Cubase so far, performance or otherwise, apart from one:
When I select the scissors tool and move it around the project window, I get glitchy audio - the whole thing slows to a crawl in fact. I’ve done a search but couldn’t find anything useful and the results were full of people wanting to make dubstep anyway (scissors tool + glitch, sigh).

Surely there’s some setting or other I’m missing as this seems to be a “binary” issue, i.e. when it’s fixed, it’ll be one setting or driver or whatever that does it. Any help appreciated!

Quick specs:
Cubase Artist 8
E6600 @3200Ghz
4GB Ram
Nvidia GTX650
(A modest machine, but it is not being taxed)

OK… I’m going to come back with this!

I decided to build myself a new PC, with an i7-4790K, 8 gigs of ram and a CPU cooler the size of Texas. This was on the cards anyway as the last machine was coming up for 8 years old.

Cubase STILL spikes the CPU when I use the GUI in any meaningful way during playback (scissors tool, (cut/move parts). Now it’s not causing clicks and pops any more, it appears the sheer horsepower of the new machine is preventing that, but it’s not good. I’ve seen a few other people pop up with this issue and the suggestions, if any, seem different every time.

The only constant is my old Terratec EWS88D, which is functioning well still even at this age, it can easily record several 24bit tracks at a time at 192ms buffer. I’m fully prepared to accept that now might be the time to upgrade my audio interface, but… This only occurs in Cubase (I have standalone NI stuff and Ableton, both are fine and free of this behaviour), and only when I’m playing back a track and use any edit tool on the GUI. It seems to me to be something that can be fixed, either by Steinberg or by a tweak at my end.

Can someone at Steinberg have a look into this? It seems to be being swept under the carpet. Also, if anyone else is having this issue or similar, reply and maybe we can solve it.

How about the graphics card, was it also upgraded in the new machine?

Damn, just saw your reply. No, graphics is being driven by the HD4600 built into the i7, so it can’t be that.

I am going to be installing Cubase 8 Pro onto a machine with EWS88MT cards in a couple of days time. It’s unlikely to be the cause, but I’ll post back if anything odd happens

I installed C8 Pro onto a system with an EWS88MT last night. No problems graphically.

I had slight problem with a corrupted file of Preferences which I tried to import. Imported a slightly older version which worked fine. No other problems anywhere. Graphics spot on.