Base 27” iMac (late 2012) - UI smoothness

In AnandTech’s review of the 13” rMBP, it mentions that the UI frame rate is not always 60 frames per second but can drop significantly below this. Now the 13” rMBP’s resolution (2560 x 1600) is pretty close to the 27” iMac’s (2560 x 1440), and while the 13” rMBP has a weaker GPU than the iMac, the review mentions the frame rate appears to be limited by single thread CPU performance rather than GPU performance. (Quoting from the review: “In every situation where UI frame rate drops significantly on the rMBP, the offending application usually ends up consuming 100% of a single CPU core.”) The base 27” iMac CPU speed is 2.9 Ghz (turbo is 3.6) while the rMBP is 2.5 GHz (turbo 3.1) so the iMac’s single thread performance should only be ~20% greater.

Here my question:

does the base 27” iMac have a good (60 frames per seconds) UI frame rate?

I’ve personally had a play around with one of these iMacs and don’t recall having any problems but my time was limited and I was probably not looking at complicated to display web pages etc.

Those of you that have one of these, I’d love to hear your experiences to date.

Anyone?

Is this a complete non-issue??

How about prior 27" iMacs? Have they ever had troubles in this regard?

(By the way, I'm new to macs. Any comments would be greatly appreciated.)

Excellent - thank you! That puts my mind at rest. Will probably put my order in later today

crows said:

I don't really get what you mean by the question the OS should be fluid, if you experience any slowdown with the UI it should be on a specific app, the OS draws the screen only where changes happen it doesn't draw every entire frame like games do...of course the OS can slowdown if 1 app is hoging all the resources but this kind of stuff is not due to any hardware configuration, I think its just the software you might be runinng and how it works..

Click to expand...

I have limited knowledge in this area - I thought the screen normally refreshes at 60 frames per second, if possible? Is this not the case?

Anyway, the main thing I wanted to know was whether the experience of using the iMac was lag free in general everyday use (so ignoring things like games, fancy video rendering software etc). For example, in the thread below, a rMBP user mentions poor webpage scrolling (Facebook, The Verge). I wanted to ensure this sort of thing wasn't an issue for the base 27" iMac.

https://forums.macrumors.com/posts/15604584/

----------

Onimusha370 said:

I got the base 27 inch, and its as smooth as butter mate

Click to expand...