Simon Brown said:

My gut feeling is that the GPU is not the cause of the problem. Please show this task manager page and make sure the CPU is visible (it may not be shown):

Is this a request by Simon for me to take a screenshot of my Task Manager Performance tab and post it here? I'll try to post a screenshot.

Simon also said:

Anyway, the GTX 645 is quite respectable when it comes to DirectX but any newer card will be better and use less power. And a newer card (if you can get one) can later be used in a new PC.

That good to hear. I'm really not in a mood to upgrade my graphics card and not solve my main issue, that is the sluggishness of my two logging apps while running SDR-C. However, if a new card will speed up refreshing on the spectrum display, I'm very interested! I just don't want to spend top dollar with no perceivable results.