Will Premier Pro work efficiently on i3 dual core 8th gen IMac ?

Actually, the non-Retina iMac that's currently available does not have an i3 - but rather a Kaby Lake (7th-Generation) mobile (budget-laptop-class) U-series i5. All U-series 7th-Generation CPUs, regardless of the branding, have only 2 physical CPU cores. Starting with the Kaby Lake Refresh (8th-Generation) mobile CPUs (which Apple does not use at all in its iMac lineup), the U-series i5 and i7 models have 4 cores.

With that out of the way, I agree with Peru Bob. No dual-core CPU is as powerful as even a mediocre quad-core CPU of the same CPU generation. Plus, your planned unit will be equipped with only 8 GB of RAM. That, combined with the complete lack of a discrete GPU, will result in your would-be-iMac choking under even the slightest of working pressure. (You can order the machine with 16 GB of RAM, but although the added RAM does improve performance, it does not hide the fact that that particular iMac is still powered by a cheapo laptop CPU that's more than three years old.)

And to add further insult to injury, even a new 2020 MacBook Air with its quad-core i5 CPU outperforms that outdated behemoth of an iMac.

Ironically, that non-Retina iMac is now currently unavailable, as well. You will have to order it, and then wait weeks for it to arrive. In my area the nearby Apple stores have, ironically, the two 21.5" Retina iMacs in stock, with the base model coming with an 8th-Generation quad-core Intel i3 CPU.

So, if that 8th-Generation i3 iMac is really what you're willing to settle with, then it is a decent choice for simple editing tasks. Its i3 CPU is actually a quad-core, not a dual-core (in other words, more akin to i5-branded CPUs of generations that came before Coffee Lake). Plus, it comes with a discrete AMD Radeon Pro 555X with 2 GB of VRAM in it. Just make sure that you order it with 16 GB of RAM instead of the base 8 GB of RAM.

Short answer:

No.  Don't waste your money on it.

Hi Abhinav Anand,

Performance in Premiere Pro is dependent on several factors. Please let us know the type of media files you will be working with (format/codec, frame rate & frame size), the effects that you may apply, and the complexity (number of video and audio tracks) of the timeline. Also, let us know the other system specifications like the amount of RAM & GPU installed on that system. Usually, dual-core i3 processors may not be able to perform better especially as the timeline gets complex. You may also refer to this link to know about the system requirements for Premiere Pro.

Thanks,

Sumeet