M3 w/ 24 GB versus M3 Pro w/ 18 GB?

[Moreplease]

I’m planning to get a 14-inch MacBook Pro.

I wish it was a sexy Air instead, but the better display and ProMotion are important to me and don’t seem likely to arrive in the M3 Air in the spring (but if they do I’ll really kick myself).

Options I’m considering are:

1. M3 with 16 GB
2. M3 with 24 GB
3. M3 Pro with 18 GB

… and after that, the European Apple prices get too silly.

All 512 GB because I’ll need external storage anyway.

•••

The heavy part of my workload is DxO PhotoLab and DaVinci Resolve.

I have no worries about PhotoLab, because I know someone who runs it fine on an Air with 8 GB of RAM with camera files bigger than mine (mine are 24 megapixels).

Resolve I use less, and I don’t use Fusion. My sources files are mainly 4K 8-bit 4:2:0 H.264.

I’m not sure what drives memory usage in Resolve: is it source file size, 10-bit files, timeline resolution, project length, project complexity, something else?

Whatever. My Resolve work is pretty basic. I don’t use a tenth of the app’s power and abilities.

•••

My options 2 and 3, above, are about the same price. An additional consideration is that option 1 (M3 with 16 GB) is available at a particularly attractive discount right now, making it a lot cheaper than 2 or 3.

But if I get the entry-level M3, it would be nice to max out the RAM to 24 GB. Because (a) it would be fun to have a top-of-the-range M3, (b) with only 512 GB of storage, I wouldn’t want to waste the NAND life writing swap files, and (c) although 16 > 24 GB is a 50% increase, the amount available for apps after system overhead, etc., would increase by more than 50% (applies even more to the 8 > 16 GB upgrade that additionally gives a 100% increase).

But the M3 Pro with 18 GB is almost the same price as the M3 with 24 GB. And I have a feeling the M3 Pro would be faster in the real world for many tasks even with less memory.

But do I need faster than fast enough? Clearly not. I need RAM so that fast enough doesn’t suddenly become downright slow when it hits the swap.

And if I was considering a Mac with 18 GB of RAM, realistically 16 GB would do about as well. And then we’re back to the entry-level M3 and saving hundreds of euros.

•••

Put me out of this miserable loop.

 

[whg]

I would always choose the MacBook with more Thunderbolt ports, especially when you have to use external storage! 18GB of RAM is OK for your use case. But if you are interested in running a local AI assistant you will need more RAM. I found that even the 36GB on my M3 Max is limiting for this application.

 

[geta]

The M3 with 24GB will cover your needs, since you considered the MBA in the first place.

 

[ric22]

I would always choose the MacBook with more Thunderbolt ports, especially when you have to use external storage! 18GB of RAM is OK for your use case. But if you are interested in running a local AI assistant you will need more RAM. I found that even the 36GB on my M3 Max is limiting for this application.

I'll second all of this. The M3 Pro is the one to get, also for the slightly better CPU, much better GPU, better cooling, quiter operation, ability to drive more than one external monitor, etc. Once you increase the RAM on the base model (which you know you need to) it makes that a very poor value proposition.

 

[bradman83]

The heavy part of my workload is DxO PhotoLab and DaVinci Resolve.

For what it's worth DxO PhotoLab's DeepPRIME de-noising engine will use the more powerful of the GPU or the Neural Engine for denoising (usually the Neural Engine). Since the NE is the same across the base/Pro/Max there wouldn't be a performance advantage for that specific task. And I think I've seen articles showing PhotoLab, at least on Windows, doesn't scale performance well beyond 4-5 cores.

 

[Moreplease]

I would always choose the MacBook with more Thunderbolt ports, especially when you have to use external storage!

I’m not too worried about having two versus three Thunderbolt ports.

However, it’s useful that the M3 Pro model has ports on both sides.

And I think the M3 Pro has Thunderbolt 4 while the M3 has only Thunderbolt 3. If so, what difference would that make?

 

[Moreplease]

The M3 Pro is the one to get, also for the slightly better CPU, much better GPU, better cooling, quiter operation, ability to drive more than one external monitor, etc.

Is the M3 Pro model really quieter? I know it has two fans versus one, but I presumed that was cancelled out by the increased heat output of the M3 Pro chip. But just guessing. Keen to hear about experiences or reviews on this point. Quiet operation is very important to me.

Once you increase the RAM on the base model (which you know you need to) it makes that a very poor value proposition.

And I’m considering increasing it twice (to 24 GB). That costs a lot but would result in 24 GB versus 18 GB of RAM if I went with the M3 Pro. What do you think about that trade-off?

 

[Moreplease]

For what it's worth DxO PhotoLab's DeepPRIME de-noising engine will use the more powerful of the GPU or the Neural Engine for denoising (usually the Neural Engine). Since the NE is the same across the base/Pro/Max there wouldn't be a performance advantage for that specific task.

Yes, DxO says it relies heavily on the NE. That’s interesting that the NE is the same on these chips.

And it is PhotoLab’s advanced noise reduction that makes the computer work on export. I was astonished that my friend’s lowly MacBook Air with 8 GB of RAM was about five times faster at exporting than my 2019 iMac with 64 GB of RAM and 6-core i5 3 GHz CPU plus discrete graphics. I’m waiting over 30 seconds per photo, which becomes hours for a big batch. And all that time the fans are screaming.

That friend’s demo is what got me lusting for a laptop again. The performance is far better than it was when I bought my iMac for its extra speed over the 2019 laptops.

And I think I've seen articles showing PhotoLab, at least on Windows, doesn't scale performance well beyond 4-5 cores.

I see.

Another factor is that the M3 Pro that I’m looking at has five performance cores and 14 GPU cores. That doesn’t sound hugely better than the M3’s four and 10 respectively. (It is the upgraded M3 Pro chip that widens the gap to the M3, but I can’t afford that. I’m already stretching to consider these machines and RAM upgrades in the first place.)

 

[Fishrrman]

M3pro.

That was easy, wasn't it ??

 

[Moreplease]

M3pro.

That was easy, wasn't it ??

Sure was! Thanks.

But you didn’t show your working out – especially why 18 GB beats 24 GB. I guess that’s the trade-off I’m most curious about.

 

[bradman83]

Sure was! Thanks.

But you didn’t show your working out – especially why 18 GB beats 24 GB. I guess that’s the trade-off I’m most curious about.

I can't speak for DaVinci Resolve's RAM needs but here's a shot of my Activity Monitor of my M1 Pro 16GB system with PhotoLab open and having been used to export several 24 mpx raw files, Affinity Photo v2 open with three 24 mpx TIFF output files, Firefox with four tabs open and a few background apps running.

You can see my memory pressure is fairly high and swap is being used, though I would add that the system in no way feels slow because the SSD swap is so fast. macOS also likes to load lots of cache items into RAM and purge or compress those as other apps need the space.

This wouldn't be considered an extreme photo editing workflow by any means. To be honest I often push my system even harder as I use Lightroom and DxO PhotoLab in tandem and I use Photoshop (and plugins like Luminar Neo) for certain tasks which gobbles up even more RAM than Affinity and I never feel like the system slows down. 18 GB would give you some more wiggle room so I would say you'd be fine with it so long as you don't try to run both PhotoLab and Resolve at the same time. That being said 24 GB would be good for future-proofing, especially if you start working with higher resolution image files beyond 24 mpx.

Interestingly Affinity Photo's RAM usage dropped by nearly a gigabyte to 1.95 GB when I closed two of the three TIFF files, and did so instantly (Photoshop isn't nearly as kind about giving up RAM cache when you close a file).

 

[MacProFCP]

This is a tough question because despite your limited use of DaVinci, you typically want a Pro or Max for that.

On the other hand, for pro use, 24 GB of ram isn’t anything crazy.

I recommend you go with the 24 GB of ram as you may end up waiting a bit longer on rendering and other high end processing but at least the machine will do the standard “stupid work” faster with more ram. Meaning that your efficiency overall is likely going to be better with more ram despite this possibility being slower in certain situations.

People will disagree because with SOC, so much of everything is everything, but this is my recommendation. More ram. Period.

 

[Sami13496]

Come on, is the screen really that much better or is it marketing… if your heart says Air why betray yourself? Just saying…

 

[_Mitchan1999]

If you’re on a budget then just get the M3 with 16GB RAM, if not then get the M3 Pro with 18GB RAM.

 

[ric22]

Is the M3 Pro model really quieter? I know it has two fans versus one, but I presumed that was cancelled out by the increased heat output of the M3 Pro chip. But just guessing. Keen to hear about experiences or reviews on this point. Quiet operation is very important to me.


And I’m considering increasing it twice (to 24 GB). That costs a lot but would result in 24 GB versus 18 GB of RAM if I went with the M3 Pro. What do you think about that trade-off?

In terms of noise, reviewers tend to say the M3 Pro is both quieter and cooler during testing. Check this one out:

M3 vs M3 Pro: The Ultimate Mac Showdown

Explore the M3 vs M3 Pro dilemma — clear comparisons, smart insights, and easy choices for your next tech upgrade!

medium.com

If you're afraid you'll be absolutely hammering the RAM, then 6GB difference might help, but it's not a big difference. Maybe 36GB would be safer for you, despite the horrendous $400/£400 upgrade bill. 😬

 

[ric22]

OP, ideally you'd test your RAM usage on another Apple silicone Mac... open everything you might use, a bunch of tabs to boot, and see where you get to. Otherwise you need to research the likely usage of each app. Definitely give yourself a few GB headroom. Being short on RAM sucks...

Potentially you could even buy a Mac, and return it for one with more RAM if needs must? Apple have everyone in a predicament with memory and storage now it is soldered (and ridiculously pricey).

 

[ignatius345]

I need RAM so that fast enough doesn’t suddenly become downright slow when it hits the swap.

This isn't 2006. Disk swap doesn't grind your computer to a halt like it used to before we all had ultra fast SSDs in our Macs.

 

[okkibs]

Two more things to complicate or simplify the decision: The M3 chip models have better battery life than the M3 Pro/Max versions. If battery life beyond 7-10 hours is super important to you that might mean the M3 version is better suited.

And you won't get proper 120Hz. The panels in these Macbooks have such slow response times around 30ms grey-to-grey that the pixels cannot switch to the next image fast enough to keep up with 120Hz. To be able to actually update the content 120 times per second the response times would need to be at around 10ms. This means you will never get the same responsiveness as on a low response time gaming monitor or even an OLED screen. With ProMotion it performs just a bit better but remains closer to 60Hz than to proper 120Hz.

For memory just look at what you are currently using in Activity Monitor and pay special attention to the memory pressure color in the bottom left corner. If you have 16GiB now and it turns from green to yellow a lot during your work then that indicates you are already at the limit and will profit from having some headroom over the next couple of years. If the memory pressure remains in the green at all times then the amount of memory you have now should suffice.

The 24GiB model might not be a good idea. If 16GiB aren't enough then chances are you'll want 32GiB anyways. The memory upgrade costs enough as it is and then Apple doesn't even give you 32GiB with the M3 chip. But some people might need just a tad more than 16GiB and 24GiB might be a good option for them. I'd just get the M3 Pro with a memory upgrade, these devices have so much performance you can really use them until Apple stops supporting them 7+ years down the road. And if you calculate how much that Mac costs you on a yearly basis you'll find that over such a long time a couple hundred bucks for more memory won't make a big difference.

With Intel many Macbooks were already underpowered and throttling due to heat right out of the box and I was happy to replace them within 2-4 years. Now with Apple Silicon I can easily use Macbooks twice as long. My M1 Max still has more power 2 years down the road than I need and the 64GiB upgrade means I can use this thing until it falls apart, memory will never be an issue. Even with all the expensive upgrades keeping this thing for a long time makes it cheaper than all the Intel Macbooks before.

 

[Eric_WVGG]

I can't speak for DaVinci Resolve's RAM needs but here's a shot of my Activity Monitor of my M1 Pro 16GB system with PhotoLab open and having been used to export several 24 mpx raw files, Affinity Photo v2 open with three 24 mpx TIFF output files, Firefox with four tabs open and a few background apps running.

You can see my memory pressure is fairly high and swap is being used…

A token amount of swap is always being used, I think it has to be there just so it can be initialized at all.

I just checked the RAM usage on my M3 Max…
physical: 36gb
used: 31gb
swap: 533.8mb (just like yours)

My vote would also be for the M3 Pro w/ 18mb, Apple Silicon is so much more efficient with the way it uses RAM. (I got by on an M1 Air with 8gb while waiting on the MBP for a while, loved it.)

 

[ric22]

Two more things to complicate or simplify the decision: The M3 chip models have better battery life than the M3 Pro/Max versions. If battery life beyond 7-10 hours is super important to you that might mean the M3 version is better suited.

And you won't get proper 120Hz. The panels in these Macbooks have such slow response times around 30ms grey-to-grey that the pixels cannot switch to the next image fast enough to keep up with 120Hz. To be able to actually update the content 120 times per second the response times would need to be at around 10ms. This means you will never get the same responsiveness as on a low response time gaming monitor or even an OLED screen. With ProMotion it performs just a bit better but remains closer to 60Hz than to proper 120Hz.

For memory just look at what you are currently using in Activity Monitor and pay special attention to the memory pressure color in the bottom left corner. If you have 16GiB now and it turns from green to yellow a lot during your work then that indicates you are already at the limit and will profit from having some headroom over the next couple of years. If the memory pressure remains in the green at all times then the amount of memory you have now should suffice.

The 24GiB model might not be a good idea. If 16GiB aren't enough then chances are you'll want 32GiB anyways. The memory upgrade costs enough as it is and then Apple doesn't even give you 32GiB with the M3 chip. But some people might need just a tad more than 16GiB and 24GiB might be a good option for them. I'd just get the M3 Pro with a memory upgrade, these devices have so much performance you can really use them until Apple stops supporting them 7+ years down the road. And if you calculate how much that Mac costs you on a yearly basis you'll find that over such a long time a couple hundred bucks for more memory won't make a big difference.

With Intel many Macbooks were already underpowered and throttling due to heat right out of the box and I was happy to replace them within 2-4 years. Now with Apple Silicon I can easily use Macbooks twice as long. My M1 Max still has more power 2 years down the road than I need and the 64GiB upgrade means I can use this thing until it falls apart, memory will never be an issue. Even with all the expensive upgrades keeping this thing for a long time makes it cheaper than all the Intel Macbooks before.

I'm not a big fan of Apple's "120hz" Mac screens for that reason. This thread covered it well: https://forums.macrumors.com/threads/m3-worse-pixel-response-times.2410638/

 

[Moreplease]

I can't speak for DaVinci Resolve's RAM needs but here's a shot of my Activity Monitor of my M1 Pro 16GB system with PhotoLab open and having been used to export several 24 mpx raw files, Affinity Photo v2 open with three 24 mpx TIFF output files, Firefox with four tabs open and a few background apps running.

Hey, thanks for going to that trouble for me. I appreciate it.

You can see my memory pressure is fairly high and swap is being used, though I would add that the system in no way feels slow because the SSD swap is so fast.

Yeah, looks decent to me. Although indeed there is a fair bit of “memory pressure,” I think that must be mainly because there is not much free memory (headroom if things get worse). Because the swap used is actually very little (consider how quickly 500 MB would be written to the drive in these machines). Though what really matters for performance is the swap rate: how fast the number is changing.

I guess memory pressure is a pretty crude indicator, albeit more useful than any individual metric.

macOS also likes to load lots of cache items into RAM and purge or compress those as other apps need the space.

Yes. You see some of that in your screenshot too.

To be honest I often push my system even harder as I use Lightroom and DxO PhotoLab in tandem and I use Photoshop (and plugins like Luminar Neo) for certain tasks which gobbles up even more RAM than Affinity and I never feel like the system slows down. 18 GB would give you some more wiggle room so I would say you'd be fine with it so long as you don't try to run both PhotoLab and Resolve at the same time.

I never run two demanding apps at once and usually am pretty good at doing one thing at a time.

Thanks for your interesting comments. Food for thought.

 

[Moreplease]

I recommend you go with the 24 GB of ram as you may end up waiting a bit longer on rendering and other high end processing but at least the machine will do the standard “stupid work” faster with more ram. Meaning that your efficiency overall is likely going to be better with more ram despite this possibility being slower in certain situations.

People will disagree because with SOC, so much of everything is everything, but this is my recommendation. More ram. Period.

That’s my gut feeling too. It just kills me to pay Apple’s European prices for two memory upgrades in a row (8 > 16 > 24 GB).

At least with custom silicon (M3 > M3 Pro), Apple’s prices seem like less of a rip-off … at least if you don’t think too hard. I’m sure Apple is making good bank there too.

 

[Moreplease]

Come on, is the screen really that much better or is it marketing… if your heart says Air why betray yourself? Just saying…

It’s a good point even if made in fun. Couple of reasons to prefer the Pro screen though:

• I guess I should figure out HDR before I get left behind
• I assumed the Pro has a wider colour gamut than the Air although I haven’t checked the details
• And I’d like the ProMotion for better motion cadence with 24p video, which seems to be an atypical reason to want ProMotion. Though I see other commenters have now thrown up new concerns about whether ProMotion is worth much with slow pixels. Gee …

 

[Moreplease]

Two more things to complicate or simplify the decision: The M3 chip models have better battery life than the M3 Pro/Max versions.

I noticed that. It confuses me. I get that an M3 Pro at full tilt will suck more power than an M3, but it surprises me that an M3 Pro (with more efficiency cores) would use more power to do the same task, like browsing the web or playing a video (Apple’s benchmarks).

Which made me wonder if maybe the real difference is 8 GB versus 18 GB of always-powered RAM. And then I started wondering about the true battery life of an M3 with 24 GB of RAM. Maybe it’s not so impressive after the memory upgrade?

If battery life beyond 7-10 hours is super important to you that might mean the M3 version is better suited.

It’s not important to me.

And you won't get proper 120Hz. The panels in these Macbooks have such slow response times around 30ms grey-to-grey that the pixels cannot switch to the next image fast enough to keep up with 120Hz.

Oof. I had no idea about this.

Maybe you’re the person to ask. The only reason I’m interested in ProMotion is for smoother 24p video playback. My wife has a big iPhone with ProMotion that has noticeably better motion cadence with 24p video than any of my devices (2019 21.5-inch Retina 4K iMac, ancient iPad, iPhone 13 mini). So that was appealing. Do these slow pixels rule that out too?

I never game and don’t care about smooth scrolling, etc., although obviously the same mechanics might apply to my concern.

For memory just look at what you are currently using in Activity Monitor and pay special attention to the memory pressure color in the bottom left corner. If you have 16GiB now and it turns from green to yellow a lot during your work then that indicates you are already at the limit and will profit from having some headroom over the next couple of years. If the memory pressure remains in the green at all times then the amount of memory you have now should suffice.

Trouble is I put 64 GB in my iMac because it was so cheap. I know that’s overkill but not sure by how much. Also, my iMac is Intel and has discrete graphics. So there’s a lot of extrapolation and guesswork. Appreciate your suggestion though.

 

[Moreplease]

Have read everyone’s replies and am very glad I posted. You’ve brought up new things I hadn’t known or properly considered. Thanks!