Bigger performance difference: More RAM or faster CPU?

[swwack91]

I'm considering buying an 11" MacBook Air as a secondary computer. I'm a freelancer in the media production industry and have a maxed out 15" rMBP that I use in the office every day. I often need to do intensive video functions on that machine.

I don't like to commute with that laptop every day and have been using a 7-year-old MacBook Pro (C2D) at home. That machine just died and I'm considering replacing it.

From the base model 11" MacBook Air, which would make the biggest noticeable performance increase —*upgrading from the i5 to the i7 CPU or upgrading from 4GB to 8GB of RAM?

Every once in a while, I'll need to use the Air to watch uncompressed 1080p or even 4K footage, but won't be editing or transcoding on it.

 

[bgfanauk]

i7 may be better

It all depends on your usage of computer, of course.

If you'll do all intensive video function with your rMBP, then there's really no reason for i7.

More ram is usually better for every day general computer use, because people usually like to open several different applications at the same time. Also, the OS's usually like more ram so they can put all of their craps on the background service.

You can look in this way. The data transfers to Ram from HDD, and to CPU from ram, in a nutshell. I mean it's a lot more complicated process if you want it in detail. Anyway, so there's the transfer rate between HDD and RAM, between RAM and CPU, and the processing rate at CPU. Since the transfer rate between RAM and CPU are as fast as CPU processing rate, (thanks to DDR2/DDR3 tech) we can ignore that.

For encoding video, it uses lots of CPU power, making the data "stay longer" in CPU to be processed. So, the transfer rate between HDD and RAM is not that much bottlenecking you, so you don't have to have a large RAM, but you would want a faster CPU. In every day use, like browsing internet or using Office, either i5 or i7 CPU processes them quickly, so the data does not stay long in CPU. Then, the transfer rate between HDD and RAM becomes your bottleneck. At that point, you do want to get a larger RAM, so RAM can take as much data stuff from HDD as it can at one batch, so it doesn't have to access HDD as often.

So, I think 8gb ram will serve you better. I'm sorry for the wrong title.

 

[thats all folks]

I'm considering buying an 11" MacBook Air ... intensive video functions ... use the Air to watch uncompressed 1080p or even 4K footage

One of these things is not like the others. Is what you wrote, what you mean? Watch 4K footage on an 11" Air?

RAM. the need is determined by the applications you are running and the work they are doing. I've found 48GB practically a minimum for intense graphic video and design work. But again, depends on your applications and how you use them. See what kind of disk swaps you are dealing with now.

Processor and Graphics. The Air is just not a big time operator. The parts are all designed and optimized for low power consumption. And if you do get them cranked up, the Air just cant move a whole lot of heat, meaning the machine will slow down even more once you get it going.

Are you sure you want an Air?

 

[Macman45]

RAM every time...the differences in GPU performance are only really noticeable in certain apps.

I have an iMac with 32GB of RAM in it and an i7 but the extra memory makes the biggest difference...you won't suffer page outs which cause slow downs and beach balls.

 

[themumu]

As far as Air is concerned, doubling RAM is more important than the bump in CPU power.

That said, I don't know how well it will pull 4K video, regardless of the upgrades. If that's what's important to you, I suggest you take a USB stick with some sample video on it, go to the Apple store and try it out on a few computers. Copy it to the laptops' SSD first, so you're not limited by the peripheral port throughput.

 

[swwack91]

Thanks, everyone. This is some really solid advice.

The primary use for the computer will be simple office tasks, but I would probably start to use it when shooting in the field instead of carrying my 15" rMBP. I will occasionally need to scrub through 4K footage (just watch, not work with it any other way), so I do want to be sure it can handle that.

I'm going to do exactly what was suggested — plop some 4K footage on a USB drive and bring it to an Apple Store to do the test.

Looks like RAM won the day!