microapp
Check the RAM usage in the performance monitor and/or Task Manager to see if you are anywhere near 8GB.
Unless you are running several instances of Kontakt or some other sample based synths, I doubt you will even notice doubling the RAM.

 
Exactly. If you are not maxing out your existing RAM, then you don't need to add any more RAM. I've only got 6GB and its sufficent for me. I don't have Kontakt though.

My desktop and my previous laptop both still had 8GB and were fine with that. I don't do orchestral stuff really but I do use plenty of Kontakt for piano, Rhodes and the odd string part or something more specific. They're both I7 though and I think the extra cores really make a difference, especially now with plugin load balancing. To be completely frank I would never even consider building a DAW with anything less than a quad core I7. Are there no I7s that fit in your mobo?

tomixornot has the right idea.
 
If you are engineering an upgraded system, the first requirement is to determine what problem the present system is having that the new one will solve. The processor upgrade will possibly allow you to run with smaller audio buffers (for lower latency), and is most likely to help if you use a lot of CPU intensive softsynths or effects. More memory can allow you to run more from memory, and if you are using samples that can be loaded into memory (as opposed to live streaming from a disk) can give you ultrafast access to samples. If you have so little RAM that you are constantly writing to virtual memory, then your performance will well and truly suck, but otherwise you may be surprised at how little you need. You can get a good idea about what you need by using the Windows Resource Monitor, as well as the SONAR metrics, which are not exactly measuring the same thing. If you are already running your projects without having dropouts at low latency, then you should probably not change anything.  Wait a few years when anything you buy now will be out of date, and you can justify expenditures then in order to be compatible with the as yet not invented software and hardware of the future. If you spend now on stuff that will not improve your workflow, you might not have it when your needs increase, or your system is aging out of new technology in the future.

its a tough call Rod, I do know the place I deal with directly (Microcenter) have stores across the continental US.
they and a lot of other places that sell RAM (like New Egg, Exc) will allow you to return it if you find it "Defective" per say. some places wont even ask, just simply send it back and get your money back. Its hard to say with RAM, especially considering the each of us work individually in different ways. Some of us use a large amount of soft synths/sample library's, mixed with Audio tracks. while others use a ton of soft synths/sample library's which determines a large amount of how your RAM is being dispersed.
 
Back to my original suggestion, Order the RAM and give it a test run. if you don't like it, return it and get your money back. kind of a no loss situation. I've built several  DAW's in my time, both AMD and Intel and I have found Intel to be much more expensive and for years I battled with the assumption that the money was not justified for the extra price of an Intel. but after this latest build (I build back in April) I have a different opinion. I believe the extra money is well worth it for the Intel. they just seem to process everything so much faster.
 
I built a top of the line AMD build 3 years ago and it was fast. I had many debates with Jim Raseberry over the differences between AMD and Intel and I still stick by most of my theory's but he was right. Intel is far superior to AMD. though I will give AMD the upper hand when geared toward some of the gaming systems.
but were not playing World of Warcraft here
 
when your ready to upgrade (even if its in a few years) call me, I'll walk you through it.
we'll get a list together and build it from scratch. trust me I was in the same situation. I saved for almost 2 years putting change aside, extra money, sold one of my desks (Tascam M-50) and did it up good.

You might check into the specs of your current processor compared to the i7 you are looking at buying. The number of cores and/or threads help but they don't scale linearly. Doubling the amount of cores does not mean it will be twice as fast - lots of factors affect performance here... Doubling of the L2 cache on the chips help too but it does not double the performance.
 
Clock speed does scale so if the new cpu is twice as fast then that would be a big help.
 
As to RAM, it helps but again if you double your ram it is not going to double the speed. I can see more ram helping if you have a lot of audio clips that require caching or vsti's that have large samples.
 
I know this is still all very subjective but it depends on your system, what you use (Sonar, Vegas, games) and how you use them (multiple large audio tracks, many video effects, etc.). If and how the developers use multiple cores is a factor too.
 
One thing to consider is that if you do buy additional ram, you may be able to use it when you do upgrade to the i7.
 
I will also second what Chuck said. In my experience there are a lot less issues with intel cpu's. The old intel cpu and motherboard combos were rock solid and almost bulletproof. Too bad they don't make consumer boards any more. <sigh>

I do believe the difference between an i5 and i7 is the latter has hyper threading.  Also look for ways to reduce resources in your projects. I believe most developers these days care less about resource efficiency. 

The answer is of course to upgrade both. :)
I'm a big believer in more RAM is always a good decision. I like to have enough RAM in my system to completely eliminate the need for a page file. It's true that after a certain point more RAM doesn't speed things up, but it doesn't slow things down either. So if you're more able to purchase RAM now, I'd say get it. Once you have enough, then you can go for that CPU.

kevinwal
The answer is of course to upgrade both. :)
I'm a big believer in more RAM is always a good decision. I like to have enough RAM in my system to completely eliminate the need for a page file. It's true that after a certain point more RAM doesn't speed things up, but it doesn't slow things down either. So if you're more able to purchase RAM now, I'd say get it. Once you have enough, then you can go for that CPU.

I agree with this in principle but I assume your current PC uses DDR3 RAM. The current I7's use DDR4 which is not compatible. If you update to the older I7-4790K (which is still a good chip) or a Broadwell family chip , you can use your DDR3. If you update to to Skylake or newer DDR3 will not work as DDR4 is the latest and greatest.
I would advise you to save your $$$ for a new CPU/PC. Have you looked at whether you motherboard will support a better CPU.
I had an E8400 CPU with 6GB of RAM and never had show-stopper issues with some fairly substantial projects.
Just get by for now with freezing synth tracks or tracks with monster FX chains if you have memory issues until you can afford to upgrade the CPU.

kitekrazy1
 
I do believe the difference between an i5 and i7 is the latter has hyper threading.  

You are correct, basically hyper-threading and cache are the only two things separating an i5 from an i7.
Similar to my 4790k. its a quad core but shows 8 threads in Sonars Performance module.
 
For a 300.00 dollar CPU this thing fly's. (with only 16GB of RAM) That's the one I linked in my first post (The Devil's Canyon).
I've done a lot of testing over the years. I have built many PC/DAW's. Im not going to lie, this latest build would have been easy but it turned all trivial on me because of one stick of bad RAM. didn't take long to troubleshoot but I was convinced at first, I didn't have the CPU locked down tight enough, thus causing a Blue screen after posting.
 
if I had not been so ignorant and not gone with my gut instincts, it would have been a 2 second fix.
but instead, I tested the RAM last .
 
 

I think the I5 (at least the haswell one) benchmarks single core at 7000-ish and the 4790K at 11000-ish.
Most of that is due to the higher clock (4.0 Ghz). Throw in the hyperthreading and Sonar will exhibit really noticable improvement.
Both the I5 and 4790K use LGA1150 socket and both use DD3 RAM.
Rodreb may be able to simply swap the CPU in his PC then buy more DDR3 RAM when he can afford it.
Just make sure motherboard/bios supports 4790K (it should).