Quad Core vs Dual Core

[artmaltman]

Do any of you know whether quad core is an advantage over dual core when it comes to editing photographs in Lightroom and Photoshop?

I'm debating MacBook pro 13" (dual) vs 15" (quad) and really, I'd rather have the smaller one. The issue is whether the quad core would make Photoshop and Lightroom run noticeably faster when editing photographs. I get into very detailed editing on headshot. Lightroom in particular will bog down tremendously sometimes.

All of my software is most current version, always. Currently using a 2015 MBPr 13" maxed out I7 16gig memory. Considering the latest (2017) MBPr models.

My impression is that Photoshop and Lightroom use only one core, so what matters more is the speed of that one core, in which case the 13" at 3.5mhz is actually faster.

SO, do any of you know whether quad core is an advantage over dual core when it comes to editing photographs in Lightroom and Photoshop?

Thanks!

Art

ps: I have read that use of the dedicated GPU on a 15" would actually slow down these programs when editing photographs. That it's best to turn off the dedicated GPU. Have any of you confirmed that via testing?

 

[Hal P Anderson]

I just tried a really mickey mouse experiment on my quad-core i7. Brought up Windows Task Manager and watched the CPU graphs as I ran the Exposure slider back and forth, back and forth. All 8 of the CPU graphs (I have hyperthreading) hovered around the 50% mark. So I guess it uses all the cores, but doesn't seem to max them out. It could be that Adobe throttle back to 50% per core so it doesn't hog all the CPU cycles.

On the other hand, creating previews and exporting will run all the cores at 100%.

I find that enabling the GPU doesn't seem to make things either faster or slower on my machine. I leave it on, though.

 

[artmaltman]

I just tried a really mickey mouse experiment on my quad-core i7. Brought up Windows Task Manager and watched the CPU graphs as I ran the Exposure slider back and forth, back and forth. All 8 of the CPU graphs (I have hyperthreading) hovered around the 50% mark. So I guess it uses all the cores, but doesn't seem to max them out. It could be that Adobe throttle back to 50% per core so it doesn't hog all the CPU cycles.

On the other hand, creating previews and exporting will run all the cores at 100%.

I find that enabling the GPU doesn't seem to make things either faster or slower on my machine. I leave it on, though.

Thanks for doing this! It sounds like a definitive test.

 

[Hal P Anderson]

Don't put a lot of faith in it. Lightroom has always performed well for me, but people with truly awesome machines sometimes come to these forums with tales of horrendous slowness. That said, if I were you, I'd go with the 4-core.

 

[Zenon]

Adobe has announced a major performance update coming with 7.2. Seems geared for expensive machines. Tested on 8 + cores and 32 +64GB rams for both Mac and PC but says if you have 12GB ram you will see a difference. We shall see.

 

[tspear]

With Lr 5.X; I think the dual core would have been better.
Since Lr 6.X when they added the initial GPU support, each patch/version has incrementally improved the multi-core functionality.
On my Windows machine with Lr 7.1, AMD Ryzen 1700 with 8 cores with a 1060 GPU; I can see many of the basic adjustments use multiple cores. Especially with local adjustments. The more local adjustments you have the more Lr seems to spread the load. While some functions like playing with the tone curve yielding one or two cores working.

Tim

 

[clee01l]

I have both a dual core rMBP (8GB) and a quad core iMac with 32GB The rMBP struggles but can do an adequate job for a laptop but I would not want to depend upon it for my only machine. If you do a lot of photo processing I'd recommend a desktop over a laptop

LR has been shown to use up to 6 cores if available and always makes heavy use of the cores available.

 

[PhilBurton]

Adobe has announced a major performance update coming with 7.2. Seems geared for expensive machines. Tested on 8 + cores and 32 +64GB rams for both Mac and PC but says if you have 12GB ram you will see a difference. We shall see.

Yes, and if these performance improvements require a beefy system, maybe it's time to upgrade.

 

[Ian.B]

still on the performance thing: i5 or i7 ?? . I have heard i7 has far more benefits in video/gaming/and the likes than photo editing.
My Acer laptop is i5 and seems good enough. The older ASUS is i7.
I'm over laptops and will likely move back to a PC very soon ---- will likely sell the two laptops and get a small 'travel' laptop.
Yeah; MORE $$$ into a hobby; and a 1/2 interesting hobby at that atm --- too hot here with temps of 40-44c not uncommon

 

[Zenon]

Yes, and if these performance improvements require a beefy system, maybe it's time to upgrade.

They must in cahoots with the computer manufacturers. Ain't gonna happen until it's time to happen.

 

[Zenon]

I'm not that savvy with this stuff so I'm going to ask a dumb question. How do I know ow many cores it has? I see Intel Core i5.

 

[Zenon]

I just did a random search and it appears to be 4. So I guess dual gives you 8 and so on? I did upgrade from 8 to 16MG ram last month on my iMac.

 

[artmaltman]

I just did a random search and it appears to be 4. So I guess dual gives you 8 and so on? I did upgrade from 8 to 16MG ram last month on my iMac.

The MacBook Pro 13" have dual core and the MacBook Pro 15" have quad core. Generally for any machine you have to look up the specs and it should tell you.

 

[Zenon]

OK thanks. I was looking in the About This Mac but it does not specify anywhere. I'll find it. Gives me something to do.

 

[tspear]

still on the performance thing: i5 or i7 ?? . I have heard i7 has far more benefits in video/gaming/and the likes than photo editing.
My Acer laptop is i5 and seems good enough. The older ASUS is i7.
I'm over laptops and will likely move back to a PC very soon ---- will likely sell the two laptops and get a small 'travel' laptop.
Yeah; MORE $$$ into a hobby; and a 1/2 interesting hobby at that atm --- too hot here with temps of 40-44c not uncommon

i5 or i7, which generation?
That can make a big difference depending on the tasks.

Tim

 

[Zenon]

I noticed that there were generations but still have not figured it out.

 

[clee01l]

I'm not that savvy with this stuff so I'm going to ask a dumb question. How do I know ow many cores it has? I see Intel Core i5.

Open Task Manager. Select the Performance tab to see how many cores and logical processors your PC has.

Oops! You have a Mac:
Open Activity monitor, then from the menu {Window}Click on {CPU History}. Each graph is activity on one of your CPU Cores

 

[Conrad Chavez]

OK thanks. I was looking in the About This Mac but it does not specify anywhere.

When you're in About This Mac, click the System Report button. That opens the System Information utility. Make sure Hardware is selected in the left column (it should be selected by default), and in the panel on the right, the Hardware Overview will show details about your processor.

For my Mac, it says, among other things:
Processor Name: Intel Core i7
Processor Speed: 2.2 GHz
Number of Processors: 1
Total Number of Cores: 4

 

[Zenon]

There it is. Right in front of me. I can't believe I didn't see it. I am not enjoying these golden years. All those commercials I watched when I was 25 and before PVR were full if it. Thanks.

1 processor - 4 cores

 

[sizzlingbadger]

I have a 15" and 13" MacBook Pro and I don't really notice much difference in performance, however, I do prefer the 15" screen and would choose it every time over the 13" for Lightroom.

 

[tspear]

I noticed that there were generations but still have not figured it out.

Depending on who you believe, each generation has about a 20% improvement in performance; except the jump to Gen 7 (the most recent one). Most of the stuff I have seen shows a 40% increase in performance.
The end result, for many users a Gen 7 i5 Core is faster then a Gen 5 i7 Core.... just to confuse matters...

Tim

 

[LouieSherwin]

Hi Art,

So much depends on how you intend to use your system. For example are you a casual photographer shooting JPG family and travel photos or are you an event photographer needing to process hundreds of raw images over night? For the former a MacBook Air might be more than enough but for the latter you will need some serious compute power.

If you process primarily raw then the size of the image files that you are now using and the size of images for any intended camera upgrades that you have planned should be considered. A system that performs well on 20MP files could easily start to lag when trying to process high resolution 36-50 MP files.

Another thing to keep in mind is that multiple cores can only help for processes that can be parallelized. This can be easy for things like Import and Export where Lightroom can send each image to a different core. However it is not so easy with things like the Develop module where there is a pipeline of complex matrix math that has to be applied in sequence to the entire image.

The upshot of this is that the number of cores mater for some things but not necessarily for others. The latest information I have heard is that Lightroom 6 (Classic) can only take advantage of 6 cores at most although this may be changing.

I think that the current best advice is to get the get a system with the fastest CPU, most RAM and fastest disk that you can reasonably afford with something like 4-6 cores. I currently have a MacBook Pro 15" 2011 2GHz Intel Core i7 (4 cores), 16MB RAM, 512GB SSD and internal 500GB 7200 RPM HD. I can run Lightroom Classic and Photoshop CC simultaneously with no problem.

This works quite acceptably with my Sony A7R2 for my landscape and personal work while traveling though I don't think I would be happy with this as my main system. A big issue is the limited gamut of the laptop screen when trying to work on detailed image editing. I would highly recommend a wide gamut display, NEC or Eizo if you want to do any serious gallery level printing.

I hope that this was helpful.

-louie

 

[Ian.B]

i5 or i7, which generation?
That can make a big difference depending on the tasks.

Tim

Don't get too technical Tim . Put it this way; the i5 Acer is 12 months old
This is easier


I certainly don't have any Lr5 dramas; although On1 can be slow saving files; but that's On1!

 

[David Gordon]

Open Activity monitor, then from the menu {Window}Click on {CPU History}. Each graph is activity on one of your CPU Cores

Top tip! I can see four graphs, so I must have four cores. But "About this Mac" says I have one processor and a total of two cores...

 

[Hal P Anderson]

David,

On my Windows machine, I have 4 cores and Task Manager shows 8 graphs. Your extra graphs are probably from hyperthreading which acts kind of like extra cores.

Hyper-threading - Wikipedia