User level: Level 1 (51 points)I have an iMac (21.5-inch, Late2009). I want to connect an external screen but my iMac doesn’t have a Thunderbolt connection. Can I use an adapter? Must I use an Apple screen or can I use another manufacturer’s screen. What would you recommend?
Posted on Oct 16, 2026 10:07 AM
User level: Level 9 (55,707 points)Oct 17, 2026 11:13 AM in response to Rob Bartholomew
Many third-party monitors have DisplayPort inputs. Mini DisplayPort to DisplayPort cables are cheap and reliable, as they are simple pin-to-pin cables with no active signal conversion involved.
In the event that you want to connect a HDMI monitor, I don't know if. a passive Mini DisplayPort to HDMI adapter would work, or if you would need to look for an active one.
Typical choices include:
Your Mac is too old to support 4K monitors or 4K TV sets, at least at full resolution. If color accuracy matters to you, look for a monitor with an IPS panel and 100% or near-100% coverage of sRGB (standard gamut).
User level: Level 10 (187,102 points)Oct 16, 2026 2:01 PM in response to Rob Bartholomew
a mini display port
iMac (21.5-inch, Late 2009) - Technical Specifications - Apple Support
you can use converters for minis display port to dvi, hdmi, displayport and the likes
User level: Level 1 (51 points)Oct 17, 2026 1:26 PM in response to Servant of Cats
Thanks very much, servant of cats, that’s more than helpful.
Rob.
Originally posted at discussions.apple.com/thread/256377384