I'm zeroing on buying the 2012 MacBook Air. My usage of the machine will be mostly for development work (MySQL, Eclipse, Xcode, Android, etc.). I will also be running Windows 7 with SQL Server in a virtual box or by using Boot Camp. My question is which upgrade will result in the most bang for the buck: more RAM or a faster processor? Does putting higher memory/processor make the machine run hotter?
With all that stuff you're running, you probably won't be happy with 4 GB of RAM. If it's truly an either/or decision, up the RAM unless you know that you won't be paging with only 4 GB.
The processor goes from a 1.8 GHz Core i5 to a 2.0 GHz Core i7. I'm not sure that's all that much of a noticeable increase.
As for temperature, Apple will put in a sufficiency of cooling regardless of the processor you choose. I don't really get why people get freaky about laptop heat output: any heat problem I've ever heard of is due to environmental factors that the user (not the manufacturer) has control over.
All that said, I got a 2012 MacBook Air with 8 GB RAM and the 2.0 GHz Core i7, and I'm super happy with it. It's noticeably faster than my previous, a 2011 Air with 4 GB RAM and the 1.8 GHz Core i7, but I suspect that's mostly the RAM and the better graphics between the 2011 and 2012 models.
tl;dr: probably the RAM, maybe the processor. It all depends on how you're going to use the machine.
The following are some stats of my MacBook Pro (4GB RAM, 2.3 GHz i5) right now. I'm using it for similar things you plan to use your Air for. I have a VM with Windows XP open, some Terminal windows, iTunes playing, Xcode, X11 running, and some Finder windows.
The CPU is more or less idle:
But check the RAM (yes, I have two 8GB sticks coming for an upgrade to 16GB :P):
I think that you can see quite clearly where's the bottleneck.
You should definitely upgrade your RAM.
In general - the advice is to spend money on SSD first, then RAM, and lastly the CPU. Most consumers are not CPU bound running simulations or graphics rendering calculations.
The CPU is usually waiting for it's cache to be filled (from RAM) or the RAM to be filled (from storage) so it can idle down and not use the maximum clock speed and be hitting the max thermal generation/power use.
In practice, the CPU/RAM/SSD does not make a measurable difference unless you are running benchmarks that load the CPU/GPU perfectly. In actual use - having more RAM allows many programs to be in memory, so spending your money there might make more sense if you have many programs running at once or do Photoshop/Aperture photo editing of large images.
There are no bad choices in the current Air line - all are ridiculously fast compared to the Pro Macs from a generation back. Heck, my 2011 Air still is fast and responsive even next to the new retina MacBook Pro which has seriously more RAM and CPU/GPU. Yes the new IPS retina display is gorgeous even not considering the resolution, but the 11 inch Air's display is way better than most of remaining line up if you are looking for contrast or color fidelity and doing a lot of code work.
This is how I think you should consider it:
- The extra .2 GHz (200,000,000) clock cycles that your CPU will perform every second are only actually useful if they are needed, otherwise they are running idle. You won't notice a difference until the 2 GHz processor starts cranking at about 90%, which would otherwise be the limit of the "slower" 1.8 GHz model.
Percentage wise, the CPU is only an 11% boost noticeable only at very high usages
- The RAM upgrade, is an extra 4 GB, which will be useful most of the time, especially running VMs, which consume vast amounts of memory. This extra memory will be noticed much more, since it's effect kicks in beyond 50% usage, unlike the 90% CPU usage needed for the CPU upgrade to become advantageous,
Percentage wise, the RAM is a 100% boost noticeable at mid range usage and up.
In my experience, I just have the new macbook pro with 8G memory. And I am very happy with it for the development. I am mainly using eclipse, database, listen music and safari for my work and lots of other text editor. And I sometimes checked the memory usage and it seldom has the pageout. So I think you should just upgrade your memory from 4GB to 8GB and that would make you happy.
This might sound counter productive, but given the non-upgradable nature of the MacBook Air hardware, I would very strongly suggest you save up for a wicked machine that will be future proof. I hope you don't end up in a situation where you regret not spending the extra buck now, but suffer from lower specced hardware for the entire useful life of the MBA.
In my case, I saved 3 years (as a teen) to buy a >$2,000 MacBook, and I'm still using it today, 4 years later, with quite solid hardware.
I see no reason to buy RAM from Apple. After that, decide on the processor you need and get the right model. If you see you are getting many page outs get some memory from Amazon for few bucks.
I can't tell much about the memory temps. I would guess with more memory you get less/no page outs which would probably make it cooler as it will work less but doubt its going to affect overall temps.
CPU temps depends on model and use you got to look that up if its important.