iMac i5 3,3GHz VS. i7 4,0GHz

[TinHead88]

In the iMacs the i7 is a true 4 core processor. The i5 is a dual core that emulates 4 cores. I went for i7 with Logic as it enables you to run a lot more plug ins offloading them to multiple cores. But you may not need this depending on how much you rely on CPU demanding plugins.

I'd also suggest 16 GB Ram but you could do this with third party ram.
I also went with SSD only as the spinning platters cause vibration and noise. Though it's minimal with a new 5400 platter it may still bother you in a music studio environment. You have more control if you simply add storage via USB3.

 

[Krevnik]

In the iMacs the i7 is a true 4 core processor. The i5 is a dual core that emulates 4 cores. I went for i7 with Logic as it enables you to run a lot more plug ins offloading them to multiple cores. But you may not need this depending on how much you rely on CPU demanding plugins.

Erm, I don't know where you got that information, but that isn't accurate. The desktop i5 Skylake chips are quad-core if they are labeled that way. You might be thinking of Hyper Threading, which is only available on the i7 on the desktop.

Some mobile i5 chips come with HT and are dual-core, but the iMac doesn't use any of those.

 

[TinHead88]

Yes, sorry it gets a bit confusing. Ultimately when I looked into i5 vs i7 for the late 2013 iMac I decided to go with i7 for multicore performance which Logic utilises.

In short i7 (at least for those iMacs) = a lot more plug ins due to much better multi core performance.

 

[makrom]

Since we are talking the iMac though, bare feats has done some benchmarking: http://barefeats.com/imac5k16.html

The main conclusion to draw is: the i7 is better, if your stuff is multithreaded enough like video editing. Otherwise the single core gains are small enough you might as well stick with the i5 and upgrade another component like the GPU with the money.

One should keep in mind that these results only apply to heavily multi threaded programs, which are most common in video editing and encoding. Not all programs that use multi threading actually benefit that much from hyper threading on a quad core, since they hardly have more than 4 CPU intense simultaneous threads.
[doublepost=1478145926][/doublepost]

Man, I wish we had build times in the 2 minute range... I only get that at home.

Yet you compile locally?
I know, this is an assumptious question, but I haven't worked in an environment where anything beyond unit tests aren't compiled on a build server.
But besides that, obviously there are many compilers that benefit a lot from HT. So if intense local compiling is a frequent use case, an i7 is definitely worth considering.

 

[Andreas222]

iMac i5 3,3GHz VS. i7 4,0GHz

I would like to use it mainly for audio production. Software that will be used are Logic, Ableton, Machine with a bunch of plug-ins etc. with bunch of hardware plugged via Thunderbolt and USB. Occasionally it will be used to edit photos with Adobe. And sometimes Film.

I will probably start with a 8gb or 16 and upgrade later.
The drive will also be a Fusion-drive. I want an SSD but its too expensive for me at the moment, maybe i will upgrade later.

I think the 3,3GHz will do just fine for your needs. I think it's wiser to spend your money on a 512GB flash storage upgrade. If you're working with a lot of larger files, the SSD portion of that Fusion drive will fill up quickly and you'll be stuck with a slow hard drive.

While it is possible to add a SATA SSD after the fact, it's not trivial. Have a look at the instructions on iFixit before you decide if you haven't done so already. Also a SATA SSD is nowhere near as fast as the PCIe-based flash that Apple uses.

 

[EnderBeta]

I have the i7 in my iMac.

On larger Crestron systems I have to compile 6 or more programs to run on the one controller, a .Net program to provide communications for the control system to a web based system like blackboard. Then I have to compile one or more touch panel files of verrying resolutions that can get up to or beyond 1080P with hundreds of pages and thousands of buttons. Then after all that is compiled i have to load everything.

Since I am human there are bugs which have to be troubleshot and corrected which means compiling everything at least a few more times.

The faster the machine the more projects I can complete in 30 days and the more comfortable I get to live. I'll gladly fork over a couple hundred dollars one time to get a processor that can earn me an extra 25% profit per month.

 

[Krevnik]

One should keep in mind that these results only apply to heavily multi threaded programs, which are most common in video editing and encoding. Not all programs that use multi threading actually benefit that much from hyper threading on a quad core, since they hardly have more than 4 CPU intense simultaneous threads.

Keep in mind a good chunk of that gap between the i7 and the i5 for multithreaded isn't even from HT though. HT isn't that much of a boost, since your code has to be mired in things that would halt the CPU but not yield to another thread. And the gap for such gains has never been very high.

The real gap comes from TurboBoost more than anything else. Since the i5 can go up to 3.9Ghz for ST work, and the i7 caps out at 4.2Ghz, the gap is fairly small. But push heavier quad-thread workloads, and the i5 throttles down to ~3.3Ghz, while the i7 is still able to push ~4Ghz. So suddenly the per-core performance is in bigger favor of the i7 than it was in a single-threaded test which leaned more on TurboBoost. And you should be able to see the majority of this effect with HT disabled.

This does assume both chips remain within their thermal envelope and don't throttle, though. But that just gets complicated to hash out in a forum thread.

Yet you compile locally?
I know, this is an assumptious question, but I haven't worked in an environment where anything beyond unit tests aren't compiled on a build server.
But besides that, obviously there are many compilers that benefit a lot from HT. So if intense local compiling is a frequent use case, an i7 is definitely worth considering.

Again, one of those things I'd love to leverage, but unfortunately the company I work for is a bit more established, so our builds are still rather monolithic and codebases are big enough to break tools like git without addressing the monolithic nature of it all. But it means no iMac can really build our code fast enough right now at the developer's desk.

At home I use the i7, but mostly because I do photo/video work that is multithreaded as a hobby, and can justify the cost (especially now that I don't have a laptop to upgrade on a similar schedule). My home projects aren't nearly big enough that the i7 really matters for code.