8GB vs 16GB vs 24GB M3 iMac – Which One Is for You?

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I’ve been offering buying guidance for Apple’s increasingly voluminous lineup of Macs for about three and a half years.

Every time a new machine is announced, the most common question immediately rears its head. How much memory do I need? Or, in today’s case: how much unified memory do you need for an M3 iMac?

Apple offers its own guidance on the amount of unified memory that’s right for you, but talk of “casual gaming”, “memory-intensive apps”, and “advanced projects” may not be particularly helpful.

The good news? Buying an M3 iMac with the right amount of unified memory for your needs, budget, and the amount of time you intend on keeping the machine is easy when you know how.

What is unified memory for?

It’s often said that you’ll see the biggest performance improvements from a Mac if you increase the memory. This admittedly depends on your use case, but it is, by and large, true.

Not to be confused with storage, memory works hand-in-hand with the main chip (in this case, the M3) to temporarily store data that might be required immediately, or which is due to be processed next. Put simply, the more memory you have, the more apps and files you can have open at once and available for almost immediate access at any given time. Thus, your Mac can feel tangibly ‘faster’ with the right amount of memory behind the scenes.

The M3 iMac uses unified memory as opposed to traditional RAM (random access memory) which is basically far closer – both physically and theoretically – to the M3 chip, thus allowing data to reach its intended destination sooner. This provides much higher bandwidth and lower latency.

As a result of the reduced rate of travel and greater efficiency for the data, you probably don’t need as much memory for your M3 iMac as you think. Although, it should always be noted that you can’t upgrade an M3 iMac’s unified memory once it has landed on your desk. You’re stuck with whatever you choose today.

8GB vs 16GB M3 iMac

There was a time when I’d have said “avoid 8GB of memory at all costs”. Indeed, there are plenty of people out there who still cannot get their heads around why 8GB remains the base memory option for new Macs.

Times have changed, though; we are far beyond the days of Intel Macs. Thankfully.

The M3 iMac is no different. If you don’t want to spend more than the £1,399/$1,299 starting price for Apple’s all-in-one, you’ll have to settle for 8GB of memory. But that is no bad thing – and I speak from great experience.

I’ve been running most of my business on 8GB Macs for the last three and a half years. I should note that this excludes video and audio production work (those tasks take place on either my M1 Max MacBook Pro or M2 Pro Mac mini), but everything else from general admin, to writing, publishing, and research, has always been carried out on a base spec Apple silicon Mac.

I’ve never run into an ‘out of memory’ error message. Ever. With the M2 generation, I have experienced the odd slowdown here and there due to, I think, the NAND chip issue (which we’re hoping is resolved on the M3 generation – time will tell). The point is – 8GB will suffice for a great many people if they’re doing nothing more than general computery stuff. Apple calls this “everyday productivity”, and I think they’ve nailed it.

The next tier is 16GB of unified memory, for which you’ll need to find another £200/$200. This should be the default option for anyone who has ambitions beyond regular productivity with their M3 iMac. If you want to delve into creative work (Apple specifically calls out “professional video editing” for this memory tier) and have a keen eye on resale values in the not-too-distant future, the upgrade price to 16GB is a no-brainer.

Who is the 24GB M3 iMac for?

How much unified memory do you need for an M3 iMac if 16GB isn’t enough? Well, we now have another option – 24GB. This will set you back an additional £400/$400 over the 8GB base model.

According to Apple, the 24GB M3 iMac is “best if you typically work on advanced projects, which require enormous files and content libraries”.

What makes an “enormous file” these days? Think sample libraries for music production, or massive amounts of visual content to which you’ll need immediate access when building 3D models.

Put simply, and as I’ve always said, if you need 24GB of memory, you know you need that much memory. If you’re not sure and have no idea what I’m referring to above – that’s ok; just grab the 16GB instead and save yourself some money.

What about M3 iMac storage?

As noted earlier, unified memory and storage are two entirely different things. While upgrading the former will indeed offer noticeable performance gains (depending on your use case), the latter simply gives you more space for stuff on your M3 iMac.

Sure, the more internal space you have on an M3 iMac, the more files you can store directly on the machine itself, thus not having to resort to external SSD storage. This will offer some speed improvements, but they’re marginal for most users – if noticeable at all. Plus, you can buy some very fast external SSDs these days for a fraction of the cost of Apple’s storage pricing.

Despite this, an upgrade from the relatively paltry 256GB base M3 iMac storage is sensible. For an additional £200/$200 (which you may have saved during the unified memory decision), you can increase the storage of your M3 iMac to 512GB. This is, I think, the sweet spot for most people. With cloud services doing most of the heavy lifting these days, that’s going to be plenty of room for most app collections.

Upping the storage to 1TB requires another £400/$400 on top of the base model, which really does push the M3 iMac into silly pricing territory – particularly if you’ve already invested in additional unified memory.

Remember – although you can’t add more unified memory to your M3 iMac, you can add storage at any time thanks to those built-in USB-C ports and the abundance of well-priced third-party external SSDs on the market. I’d always focus on the latter as a strategy.

Conclusion

I genuinely hope I’ve proved my point that picking the right amount of unified memory for your M3 iMac is easier than you think!

If you’re still struggling, the takeaway is as follows:

• 8GB is for people who will only use their M3 iMac for general productivity (at home or work)
• 16GB is for anyone who wants to stray beyond the above and who is concerned about future resale values
• 24GB is for people who will be doing serious creative work, development, or data-driven research (you know who you are!)

So, which M3 iMac unified memory configuration are you going for – and why?

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