If your titles or your content had nothing to do with computers, your readership looking for "fast and affordable computers" would not be happy.

I do think that a "fast and affordable computer" today is going to be "out of date" in 6 months time. This is good or bad depending on your point of view, however I would assume that a person today who is interested in "fast and affordable computers" is still going to be interested 6 months down the road in "fast and affordable computers". Grab their email addresses, and review "fast and affordable computers" on a regular basis. They would expect some sort of product review at least every month.

could you look on amazon or aliexpress under their list of categories to add content to your site.
these sites are very good for getting ideas about what people are searching for related to your niche - have a browse around and see what they offer.
have you covered upgrades? so you bought your computer a couple of years ago what can you do now to get it running faster
keyboards- mice- what advances are there is speech to text for these computers.
Who are your audience and what do they need - that's what you write about - find out on the forums what people are asking for.
is it tweaks to the operating systems or hardware or bios.
Good luck
Phil
i would use something like lsigraph to see associated keywords to your niche - it may give you some ideas

You could try something like cheap computer gadgets, or something related to them. Maybe accessories?
Anyhow, I don't recommend 'branching out' of your niche. You have readers for one reason: They are interested in your niche and want to read more about it. If you go off point from your website's purpose and start posting content not related to your niche, you could risk losing your readers. Hope this helps!
Reim