Intel Core i7-5820K vs i7-4790K for sw development & gaming

darthdeus

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Hi guys,

I'm looking to build a powerful desktop PC for my programming and gaming needs, and currently I'm having trouble deciding between i7-4790K and i7-5820K. Comparing the stats it seems that 5820K should be a clear winner, but it seems almost too good to be true.

  • Pros:
    - 6 cores
    - newer SSE 4.2 + AES instructions (not sure if I'd benefit from this yet, but I guess AES could be a plus)
    - 15MB L3 cache (still not sure if this is per CPU, or in total? though 15/12 is still better than 8/8)
    - DDR4 support
    - higher memory bandwidth and addressable 64GB
  • Cons:
    - 3.3GHz, while 4790K has 4.0GHz
    - no integrated graphics card (given that I'll have an external one, I guess I don't really care about this)
    - probably higher power usage
    - 2011-3 socket - not sure if this is a pro or a con, but since it forces me to buy a more expensive motherboard, I'll put this as a con ... but I'd like to know if there are any benefits here
    - price - though at my local retailer I can get 5820K with a nice heat sink (which I'd buy anyway), which brings the price basically equal to 4790K
 
Solution
The i7 5930k wouldn't add anything in that scenario, the i7 5960x on the other hand obviously would. But yeah, if you plan on mostly using your applications yourself, I'd opt for the i7 5820k, too.

Another important decision to make here is how much and how fast of a ram you need. Sometimes 16gb of higher clocked, lower latency ram will give much better results than 64gb of "officially supported" ram.


Edit: Uhm, confused about the "best solution" picks here, I'll unselect my post (as the last post you seemed to have chosen was the one above) and then let you have the final pick, if all your questions are answered.
Unless you have money to burn, I would go with the I7-4970K . The i7-5820K motherboard is going to more expensive. The necessary DDR4 memory is more expensive And the processor is more expensive. And after that you end up with six 3.5 GHZ cores verses four 4.0 GHz cores of the I7-4790K..
Both processors are hyper-threaded. But the i7-5820K does have more PCI lanes than the i7-4790K.

But I don't believe the I7 -5820K is worth all of the extra cost for six much slower cores ( two more cores) and more PCI lanes. Especially when you consider that a I7-4790K system is going to be very powerful anyway.
 

DubbleClick

Admirable
Depends on how large your software projects are and in what language. If you're working on projects with hundred thousands lines of c++ code, I could totally see the extra expense justified.
If you're coding in go (lang) or interpreted languages, no so much. Or if your projects don't go over a couple thousand lines of code.
For gaming, there's essentially no difference (actually the I7 4790k does unnoticeably better) unless you intend to 3-way sli.
 

anti-duck

Honorable
It all depends what you're doing. You mentioned programming so the 5820k may help you there if you're compiling some huge programs and parsing data, for gaming, the 4790k should win with its better core performance out of the box. I'm not sure if the higher TDP of a 5820k is an issue really as it (and correct me if I'm wrong) has a soldered heat spreader for better heat dissipation.

If DDR4 had achieved price parity with DDR3, then I would be saying go for the 5820k, but for the extra you're going to pay for a socket 2011 v3 motherboard and DDR4, I'm not sure it's worth it currently.
 

darthdeus

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As for my programming needs, I'm going to do lots of compiling in C/C++, probably even make use of SSE, so I guess on that point its a clear winner.



This is probably a dumb question, but can't I use DDR3 memory until DDR4 price drops?
 

LookItsRain

Distinguished


lga 2011-3(5820k) only can use ddr4, lga 1150(4790k) uses ddr3.

Besides that, both are unlocked cpus so core clock speed is irrelevant if you know how to oc.
 

JingLuci

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Core clock speed IS relevant. With the 4790K you can go up to 5ghz if you're lucky but generally around the 4.7ghz point. The 5820K however can only manage a 4.5ghz at best and if you're really lucky to get a good CPU if not generally it's around the 4ghz-4.2ghz point.
 

darthdeus

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First of all, I accidentaly clicked on the "Pick a solution" on this post, but can't find a way to undo that. I didn't mean to click on it :)

Anyway, I wanted to ask how relevant the clock speed actually is? If you're comparing 4.5GHz vs 5GHz overclocked, that'd still only matter if the app is doing heavy calculations, no? I mean the 5820K has a quite larger L3 cache, and based on my minor experience with writing high performance code, it seems that proper cache usage is way more important than clock speed.

That being said, I'm not really sure how this turns out on real SW, but looking at many benchmarks it seems that 5820K outperforms the 4790K. Also the 12 vs 8 threads should play a big factor, no? Almost everything is parallelized these days.
 

JingLuci

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What I'm saying in my comment was not about your question but more on replying to him on the statement that he made. 'Besides that, both are unlocked cpus so core clock speed is irrelevant if you know how to oc.'
To answer your question on which CPU to take, I'd most definitely recommend you the newer i7 5820K. Why? Cause it has more cores for more computing power even those it's core are running at a slower speed that the 4790K. And your work are CPU intensive work hence the more core there is the better you will fair. However to say that core clock is irrelevant if you know how to OC is wrong. Since the 4790K can go up to a much higher clock speed than the 5820K ever can. This makes the 4790K one of the more competitive CPU till now coupled with it's cheaper overall cost. More people will take the offer the 4790K has.


In single core performance the 4790K will destroy the 5820K. But if you put all the cores together and do a comparison, then the 4790K will lose out by a bit. http://cpuboss.com/cpus/Intel-Core-i7-5820K-vs-Intel-Core-i7-4790K Have a look at this website.
 

senseijtitus

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i7-5820K has a definite advantage over i7 4790K. Lets face it. It is the next generation and it has got the future proofing edge. It is more expensive as well.

If the OP can afford this CPU, then he is better of with it. But if not, go for 4790K. Will do its just well.
 

DubbleClick

Admirable


You won't notice a slightest difference between an i3 4130 and an i7 5960x if all you're doing is general browsing, work and such. The scenarios you're going to see a difference in are benchmarks, cpu intensive games and other things that go heavy on the cpu.

So yeah, in (multithreaded) benchmarks, you'll see the i7 5820k ahead of the i7 4790k - in single threaded and applications that don't distribute load perfectly well, you'll see the i7 4790k ahead of the i7 5820k.



You surely aren't going to write those applications only for yourself, huh? The majority of people has considerably weaker pc's than an i7 4790k even. On average you can expect something along sandy to haswell i3's used - unless your applications are specifically catering towards high performance needs.
That said, if you're writing high performance code, there's a lot more to it than just using level 3 cache properly - keep in mind it's the slowest cache and the next step is the ram already. Templating, metaprogramming, inlining, preprocessor instructions and many more come into play when writing high performance code.



You wish, if that was the case amd wouldn't be so horribly far behind intel.
 

DubbleClick

Admirable


No. It's the same generation. Both are haswell, absolutely the same. Aside of that, the i7 5775c is the "next generation" (broadwell) but is slower than it's predeccor, namely the i7 4790k (and the i7 5820k). There is no such thing as a "future proofing edge" (not like you'd have brought any argument for that anyway) and that it's more expensive has nothing to do with the actual performance directly. Could sell a pentium for $2000, wouldn't make it any better than an i7 4790k.
 

DubbleClick

Admirable


Don't EVER recommend that website for someone to use who isn't 100% familiar with what actually matters and what not. It's promoting things like "more threads = run more applications at once", "higher clock speed = better", "lower tdp = higher overclocking possible" and "overclocking headroom = maximal on average achievable frequency", which are all bull***t.
 

JingLuci

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Whoops. Didn't think about that. My bad. Usually I use that website to decide things for myself. It's easier for me since I know exactly what I need in my own rig.
 

DubbleClick

Admirable


From a performance per money standpoint, this is true, you would never recommend an i7 5820k over an i7 4790k. But there's scenarios where saved time is worth more or translates into money made, in which cases the former might indeed have an edge over the the latter. Although that has to be decided on application level, since one isn't per se faster than the other.

In the case of building large c++ projects, it could be worth it. You should usually always keep modules small and just put them together for a flawless done application, but that doesn't always work out without errors. In which case, saved time on that might come into play. Sure, taking 25,5 instead of 26 seconds to compile isn't a huge difference, but if you're building something really large (much larger than something like boost) the difference might be 30 instead of 35 minutes, which, done frequently, adds up quickly.
 

DubbleClick

Admirable


I personally use it too, as the benchmark scores there seem about right in general. Just the conclusions shown are usually absolutely stupid, saying a fx 9590 has more overclocking potential than an i5 4690k is just.. my god.
 

darthdeus

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Jun 23, 2015
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Thanks for the suggestions guys, I guess 5280K really is the winner here, especially after looking at DDR3 vs DDR4 prices, and while they're more expensive, it's not that big of a difference.



Or running Visual Studio and compiling C/C++, which is kind of what I'll be doing when I'm not gaming. This is why I picked i7 to begin with, since just by comparing between the laptops I have access too, i7 outperforms i5 at compile speeds by 2-4x.


Actually I am going to write them for myself :) The reason for this PC is to speed up compile & run times of C/C++/.NET code, as I'm doing quite of bit of high performance algorithmic tasks (studying computer science.)
 

JingLuci

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You have a point there. But most people here asking about CPU don't need the processing power of the 5820K. The 4790K will fit almost every one rig here perfectly. And if they actually need something of that calibre they would be looking at the 5960X.
 

JingLuci

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In that case the 5820K will fair you much better. And if you more money to throw the 5930K or even the 5960X will increase your work output even more. But that's for another time. The consumer grade of 5820K is sufficient. :D
 

DubbleClick

Admirable
The i7 5930k wouldn't add anything in that scenario, the i7 5960x on the other hand obviously would. But yeah, if you plan on mostly using your applications yourself, I'd opt for the i7 5820k, too.

Another important decision to make here is how much and how fast of a ram you need. Sometimes 16gb of higher clocked, lower latency ram will give much better results than 64gb of "officially supported" ram.


Edit: Uhm, confused about the "best solution" picks here, I'll unselect my post (as the last post you seemed to have chosen was the one above) and then let you have the final pick, if all your questions are answered.
 
Solution