An i7 is well worth the $100 or so difference in price for comparable speed of an i5. i7's utilize hyper threading and also have a bigger L3 cache. It is a better performing cpu. It should be viable longer than an i5 while getting better performance from day 1.
 
The CPU is the core of the system and bottleneck these days which will ultimately limit the system.
RAM, Graphics, Sound can all be updated along the way to extend system life.
 
If I were buying today I would get the Intel Core i7-3770K Ivy Bridge 3.5GHz (3.9GHz Turbo) LGA 1155 77W Quad-Core Desktop Processor. Best bang for the buck in my opinion. And I would lean towards an Asus board with the Z77 chipset.
 
My two cents.
 
Good luck and have fun with what ever you get!
 
 
 
 

hockeyjx
That and get an AWESOME interface.

Good enough computers are cheap now.  Good interfaces aren't.
 
You have to pay for hiqh quality, low latency.
 
So get a good enough computer and a great interface.
 

'I7s utilize hyperthreading'.

But very very few programs do, and audio production programs don't appear to be listed among hyperthreaded supported software. You don't get better performance out of the box unless you are specifically using such a program that utilizes HT.

I think that saving that $100 to put towards better audio equipment or plug ins would be better than getting an I7 just for Sonar.

Not to hijack the thread but when speaking about performance, just how much of a difference would changing your audio interface make to a decent PC system?
 
For example, I'm using an EMU 0404 PCIe and thinking of upgrading to an RME AIO.  Can I expect noticable differences in performance with regards to loaded plugins and latency?
 
I'm also looking to upgrade my PC Intel DualCore 2.8ghz, Asus P5k, 8Mb Ram, Radeon Graphics but can't afford to upgrade both at the same time.
 
Much thanks for any advice...

I've used an I5 with 8 gigs of RAM on a Windows 7 computer as my main recording rig and had excellent results. You can see the different configs in my signature. Since getting the Toshiba Windows 8 laptop, the HP laptop has been downgraded to strictly an internet computer. I have worked with all sorts of setups through the years and have found that if you spend some time doing just some small tweaks you can get most any computer to work pretty solidly. The main thing as stated before is the audio interface.

Always get the most powerful you can afford. If you can get the i7, get it. I have used i7 since it first came out and I run tracks counts of over 100 and plugin counts over 100.
 
 
CJ

i agree to get the best you can afford, but I don't have unlimited resources.  I built a new system around a year ago using an i5-3570 cause it was about $200 cheaper than an i7 and had lots of great reviews.  I had then a Win7-32 system and recently upgraded to Win7-64 w 16Gb ram.  I haven't pushed anything yet but I usually stick with 24bit/48khz projects, and now and even before I had no issues with projects with 70+ tracks, and I use quite a few fx and instruments. I do tend to freeze tracks and render tracks to reduce latency and system demands, as well as having archived tracks that I can use years from now. 

Not sure where you got that information from. Hyperthreading is
automatically used by any multithreaded program.
There is no special programming required to utilize it other than using multiple threads. The OS takes care of the rest.

Vab
'I7s utilize hyperthreading'.

But very very few programs do, and audio production programs don't appear to be listed among hyperthreaded supported software. You don't get better performance out of the box unless you are specifically using such a program that utilizes HT.

I think that saving that $100 to put towards better audio equipment or plug ins would be better than getting an I7 just for Sonar.
[/quote

4partmusic
I am starting to consider my options for a computer upgrade whether I build or buy is yet to be seen.   Is there a benefit to spending the extra money for an I7 processor over the I5.

 
So what do you want to do with you system ?
 
If you just want to record, an i5 will be more that enough and I'd spend my money on a great interface.  Think RME, etc.
 
If you want to run a bunch of synths going through effects, you may not need an interface and may need more cpu power.
 
EDIT :  just noticed you're a song writer...  An i5 will be fine, spend your money on a great interface.
 

CJaysMusic
Always get the most powerful you can afford. If you can get the i7, get it. I have used i7 since it first came out and I run tracks counts of over 100 and plugin counts over 100.
 
 
CJ

Hi Cj,
       May I know which i7 model are you using? I am using an old I5 750 CPU and my system can't handle more than 20 plugins and I am ready to upgrade to i7.
 
       I am a mainly soft synth kind of composer.