Does screen size affect performance?

[Leukeh]

I'm currently looking into buying a new iMac and trying to decided between the 21.5" and 27". The current 2.7GHz models have the same specs all around (unless I'm missing something?). My question is - since the display of the 27" is so much bigger, will the 21.5" model outperform it? Is the difference significant or is it so minimal it's not worth worrying about?

 

[pigoo3]

In the "old old" days...this would or could have been an issue. But I've heard no mention of this for any computer in a long long time. So no worries...get the 27" guilt free!

- Nick

 

[pendlewitch]

Absolutely, I've never regretted getting the 27". They may look big in the Apple Store but once they are at home in the right place on a desk they look super. You can also get an adaptor to replace the stand if you want to mount it on a wall-bracket.

Graphics are excellent and you can view multiple apps easily..add in a Magic Trackpad for super fast multi-tasking.

One thing though, they are extremely heavy to carry through a shopping mall all the way to the car by the handle on the box so plan ahead

 

[pigoo3]

Absolutely, I've never regretted getting the 27". They may look big in the Apple Store but once they are at home in the right place on a desk they look super. You can also get an adaptor to replace the stand if you want to mount it on a wall-bracket.

Graphics are excellent and you can view multiple apps easily..add in a Magic Trackpad for super fast multi-tasking.

I think that what the OP means by "performance"...is not how much work you get done...but would the larger display somehow be a drain on the processing power of the computer...versus a smaller 21.5" display.

Thus my reply above. In "older" days...this could have been a concern...but not now...since the processing power of cpu's & gpu's used are so much more powerful.

- Nick

 

[pendlewitch]

I think that what the OP means by "performance"...is not how much work you get done...but would the larger display somehow be a drain on the processing power of the computer...versus a smaller 21.5" display.

Thus my reply above. In "older" days...this could have been a concern...but not now...since the processing power of cpu's & gpu's used are so much more powerful.

- Nick

Point taken, but I did say that graphics are excellent and this, as well as viewing multiple apps and fast multi-tasking are performance related issues surely? The trackpad gestures in Lion are a marvel.

 

[pigoo3]

Point taken, but I did say that graphics are excellent and this, as well as viewing multiple apps and fast multi-tasking are performance related issues surely? The trackpad gestures in Lion are a marvel.

What you mentioned is true....but is beyond the scope of what the OP was asking.

The OP was specifically asking about performance as it relates to the 21.5" vs. 27" display sizes...and would the 21.5" "out-perform" the 27" because it was a smaller display.

This is because the OP is concerned that the larger 27" display may somehow slow the computer down (compared to the smaller 21.5" display). As I answered above...probably not considering how powerful today's computers are.

- Nick

 

[pendlewitch]

But isn't the graphics card related to screen size in the number of pixels that the card is being asked to produce?

The 27" has max 2560 x 1440 resolution and the card in mine (ATI 5670) has max digital resolution capability of 2560 x 1600.

Just curious..yes I agree I missed the point of processor related performance but is not the graphics card more important here given that it has minimum spec requirements that Apple fulfils or exceeds?

Just a moot point, the OP states 'current 2.7Ghz models' but mine off the shelf last December was 3.2Ghz ??

 

[pigoo3]

But isn't the graphics card related to screen size in the number of pixels that the card is being asked to produce?

The 27" has max 2560 x 1440 resolution and the card in mine (ATI 5670) has max digital resolution capability of 2560 x 1600.

You do bring up a very good point. Many times (when comparing the same generation iMac models) the graphics hardware between the 21.5" iMac and the 27" iMac are different...and "generally"...the video hardware in the 27" iMac is "better"/superior.

So when talking about performance between a 21.5" iMac and a 27" iMac (same generation)...we would have to have the exact same graphics hardware to truly be able to determine if the larger screen size (more pixels) has an effect on computing performance.

I haven't checked EVERY iMac "generation" to see if this "graphics card similarity" exists...but I did find one comparison...the 21.5" and 27" "mid-2010" iMac's.

Both have:

- a dual-core 3.2ghz "i3" cpu
- Radeon 5670 graphics (512meg of graphics ram)
- 4 gig of PC3-10600 DDR3 ram

So "under the hood" both of these iMac's would be essentially the same...with the only major difference being the 21.5" vs. 27" display's. So in this case...it would be interesting to see if the size of the display (more pixels) would have an impact on the computing & graphics performance of the computer.

- Nick

p.s. With the current generation "mid-2011" iMacs (21.5" and 27")...two of the models also have the same:

- processor speed (2.7ghz)
- cpu (quad-core i5)
- graphics hardware (Radeon 6770M with 512meg ram).
- 4gig of ram

So this would/could be an interesting comparison as well.

 

[pendlewitch]

I agree pigoo3 and will do some more research.

Just a point, I edited my last post because the OP talks about current models being 2.7Ghz.

Mine is a 'Mid 2010' model and is 3.2Ghz so I'm not sure what the OP is looking at ?

 

[pigoo3]

Just a point, I edited my last post because the OP talks about current models being 2.7Ghz.

Mine is a 'Mid 2010' model and is 3.2Ghz so I'm not sure what the OP is looking at ?

Two of the four currently available "stock" iMac configurations are 2.7ghz models...the same two models I was referring to in the p.s. (post script) above. One is a 21.5" model...and the other is a 27" model.

Here they are (the two middle models):

iMac Desktop Computers - Apple Store (U.S.)

- Nick

 

[toMACsh]

size matters, size doesn't matter
********the fence*********


As to the monitor, if you can detect a difference, you have outa sight eyesight.

 

[BrianLachoreVPI]

The short answer is - No.

You can check the benchmarks for peace of mind.

 

[Leukeh]

Thanks for your responses everyone.

I'll throw another question into the mix - would running two monitors effect performance?

To help, I might give some background.

I'm a graphic designer and photographer, currently working from a 13" MPB + 23" external display. The portability of the MBP used to be important while I was studying but now I don't really need it - plus my current machine is starting to lack the grunt I need.

I want to upgrade but want to get the best performance - if the 21" screen would outperform the 27" screen, given they have the same specs (as the two "current" middle models do), I would probably go for the 21" and use a second monitor. If it makes no difference... well I'll probably get the 27" and use the second monitor just because I can.

 

[zacster]

Graphics cards affect performance, not the monitor. The only thing that generally stresses the graphics card is games/3d simulation, anything where you are putting out fast moving video that needs to be computed. I know the SandyBridge i7 processor, and I think the i5 also, has a section dedicated to transcoding video codecs, usually one of the slowest things that the processor may need to do. With dedicated hardware it is much faster.

In any case, the new 27" will run circles around your MBP. Sandy Bridge was a huge processor upgrade, with new motherboards built to handle it.

Here's my advice if you are concerned, buy the 27" i7 processor model. There isn't anything faster out there, at least not from a processor standpoint. That goes for the windows world too.

 

[pendlewitch]

Thanks for your responses everyone.

I'll throw another question into the mix - would running two monitors effect performance?

To help, I might give some background.

I'm a graphic designer and photographer, currently working from a 13" MPB + 23" external display. The portability of the MBP used to be important while I was studying but now I don't really need it - plus my current machine is starting to lack the grunt I need.

I want to upgrade but want to get the best performance - if the 21" screen would outperform the 27" screen, given they have the same specs (as the two "current" middle models do), I would probably go for the 21" and use a second monitor. If it makes no difference... well I'll probably get the 27" and use the second monitor just because I can.

In my opinion no.

I'm not sure of the internal GPU limits (pixel wise),for example the 27" screen limit is 3,686,400 pixels (2560x1440) and quoted figures for earlier AMD GPU's had max limits of 64,000,000 (8000x8000).

Gaming is a different matter but not an issue for you.