Macula

macrumors 6502
Original poster
Oct 23, 2006
431
18
All over the place
I am just about to buy a 13" rMBP (I think). I need 512GB of SSD space, so I am looking at the top-tier model with either 8GB or 16GB ram. Does the decision have any performance implications with regard to external monitors? If I hook up a 4K external display to the machine, will the 16GB model handle the load better? I am asking because there is no video RAM in the model, so whatever amount of memory is required to power the external display will be deducted from the available RAM.

Many thanks.
 

snaky69

macrumors 603
Mar 14, 2008
5,904
484
I am just about to buy a 13" rMBP (I think). I need 512GB of SSD space, so I am looking at the top-tier model with either 8GB or 16GB ram. Does the decision have any performance implications with regard to external monitors? If I hook up a 4K external display to the machine, will the 16GB model handle the load better? I am asking because there is no video RAM in the model, so whatever amount of memory is required to power the external display will be deducted from the available RAM.

Many thanks.
Completely unrelated, so no effect. RAM speed would have more effect than the amount of it, and DDR3 is painfully slow compared to real VRAM.

Also the amount of RAM the intel card uses is capped.
 
Comment

maflynn

Moderator
Staff member
May 3, 2009
68,027
35,594
Boston
Ram has nothing to do with an external display. They're completely unrelated, the OS will take some ram for video memory for integrated GPUs yet, that's capped, so you'll not see any difference between 8 and 16GB.

If you're considering 16GB of ram, you need to determine your usage habits, now, estimate your usage habits in the future and discern how much memory better suits your needs.

8GB is a great amount to deal with a variety of uses now and the future, but I can understand opting for 16 because the ram is soldered onto the logic board and you cannot upgrade it in the future.

If your usage consists of emails, office docs, surfing the web, 8GB is more then enough for your needs for the short and long term.
 
Comment

SE43

macrumors member
Apr 2, 2015
95
10
I went for 16gb due to use of VMs, but I did use 8gb before and it was perfectly fine.

Depends if you want to spend the extra for it or not, based on your usage, and also based on you not being able to upgrade it in the future.
 
Comment

Macula

macrumors 6502
Original poster
Oct 23, 2006
431
18
All over the place
Well, that 1.5GB cap does seem like a significant portion of 8GB, no? It effectively reduces the RAM to a minimum of 6.5GB on an 8GB machine. Last question, if I may: what determines how much of this 1.5GB is used t a given time? Is it the number and size of monitors? Is it the scaling selected in preferences?
 
Comment

TechZeke

macrumors 68020
Jul 29, 2012
2,387
2,106
San Antonio, TX
Well, that 1.5GB cap does seem like a significant portion of 8GB, no? It effectively reduces the RAM to a minimum of 6.5GB on an 8GB machine. Last question, if I may: what determines how much of this 1.5GB is used t a given time? Is it the number and size of monitors? Is it the scaling selected in preferences?

If you're doing GPU intensive tasks, it will use more RAM. Really, if you're this unsure about 16GB of RAM, you probably don't need it. With RAM compression you'll get 12-14 GBs out of the RAM anyway.
 
Comment

Samuelsan2001

macrumors 604
Oct 24, 2013
7,694
2,123
More monitors

Well, that 1.5GB cap does seem like a significant portion of 8GB, no? It effectively reduces the RAM to a minimum of 6.5GB on an 8GB machine. Last question, if I may: what determines how much of this 1.5GB is used t a given time? Is it the number and size of monitors? Is it the scaling selected in preferences?

Will of course use more Vram, but which processes are being performed on each screen as well.

If you just tell us what you are using the computer for then you'll get far more pertinent answers to your question.
 
Comment

Macula

macrumors 6502
Original poster
Oct 23, 2006
431
18
All over the place
Well, aside from the usual non-suspects (browsing, office apps, media playing) I do a lot of background LaTeX typesetting, Xcode, and I leave a bunch of apps open in full-screen mode (about 10 at a time) switching between them all the time. There is always at least one flash video playing while this is going on. And I read enormous PDFs (in the ballpark of 500MB each). Will be using an external 4k display in extended desktop mode. I am also a bit anxious about the demands of future OS versions (I don't see myself buying another machine earlier than 4-5 years out).
 
Comment

Samuelsan2001

macrumors 604
Oct 24, 2013
7,694
2,123
Well

Well, aside from the usual non-suspects (browsing, office apps, media playing) I do a lot of background LaTeX typesetting, Xcode, and I leave a bunch of apps open in full-screen mode (about 10 at a time) switching between them all the time. There is always at least one flash video playing while this is going on. And I read enormous PDFs (in the ballpark of 500MB each). Will be using an external 4k display in extended desktop mode. I am also a bit anxious about the demands of future OS versions (I don't see myself buying another machine earlier than 4-5 years out).

With that workload the 13 inch will do it but the 15 inch will do it far more comfortably.

Don't get set in stone on how long things will last, this sounds like it is your work and if those needs change then your hardware needs may well change.

Also if this is your means of making money make sure you always have the money set aside to replace any computers that are essential to your work, any computer may just die on you and often a few days without said computer will cost you more than just buying a new one....

I would get the 13 inch and check it out, you have 14 days to return no questions asked, if it's not for you then wait for the next 15 inch update or get one of last years on a good deal somewhere or refurbed...
 
Comment

Macula

macrumors 6502
Original poster
Oct 23, 2006
431
18
All over the place
To be honest, I am glad to read your recommendation because that's what I also thought (but didn't dare admit). Quad-core seems the way to go in this instance. Unfortunately I am traveling around far too much these days to utilize the 14-day return policy. I would go ahead and get a 2014 15-incher but I am a bit of a sucker for the force touchpad (and the new Iris).

Do assume correctly that the non-dGPU 15-incher would do?
 
Comment

Samuelsan2001

macrumors 604
Oct 24, 2013
7,694
2,123
Yes

To be honest, I am glad to read your recommendation because that's what I also thought (but didn't dare admit). Quad-core seems the way to go in this instance. Unfortunately I am traveling around far too much these days to utilize the 14-day return policy. I would go ahead and get a 2014 15-incher but I am a bit of a sucker for the force touchpad (and the new Iris).

Do assume correctly that the non-dGPU 15-incher would do?

The Non dGPU would be fine, (my only issue with it is the base 256gb SSD size is a bit small!!!).

The force touchpad looks good but it's just a touchpad. The new IRIS has proven to show very little difference to the 5100 in the haswell 13 inchers in practice despite showing quite well in benchmarks. The IRIS PRO 5200 in the base 15 inch model still spanks it handily...

As for the returns policy buy it in one store return it to another should be no problem if needed...
 
Comment

maflynn

Moderator
Staff member
May 3, 2009
68,027
35,594
Boston
To be honest, I am glad to read your recommendation because that's what I also thought (but didn't dare admit). Quad-core seems the way to go in this instance. Unfortunately I am traveling around far too much these days to utilize the 14-day return policy. I would go ahead and get a 2014 15-incher but I am a bit of a sucker for the force touchpad (and the new Iris).

Do assume correctly that the non-dGPU 15-incher would do?

Why not wait until later this summer for the new 15" models? I'm sue they'll get the force touch trackpad.
 
Comment

Macula

macrumors 6502
Original poster
Oct 23, 2006
431
18
All over the place
Helpful replies, thanks. I need the machine somewhat urgently but indeed am inclined to wait until June or July. The 512GB-equipped 15-incher costs around 2900USD in Europe (that's for the model without the dGPU), and I am reluctant to shell this amount out for a machine that won't be the latest and greatest at the time of purchase.
 
Comment

Samuelsan2001

macrumors 604
Oct 24, 2013
7,694
2,123
Comment

Trapantski

macrumors newbie
Dec 4, 2019
3
0
Apologise for my ignorance, BUT...
Anyone know whether a new iMac 2019 (Retina 27", intel i9 9900K 3.6ghz, 64GB 2666Mhz RAM, 8GB Radeon Vega, and 1TB SSD) will be enough to power a Cintiq Pro 32 on canvases of 20,000x10,000 pixel (200MP) PS files? These images will have lots of layers...
 
Comment
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.