4790K vs 5775c vs 6700K

[Moson1970]

I already have DDR3 RAM and an Asus Z97-A motherboard. What I know about the processors are that the 4790K can potentially overclock very high but it has the lowest IPC. The 5775c is newer on 14nm and has an L4 cache and is on average 4% faster per clock than the 4790K but it costs more and can only overclock to 4.3GHz if I'm lucky but a 4.3GHz broadwell is on par with a 4.5GHz Haswell and I don't think I would overclock much higher due to heat anyway. The 6700K is the best all around but I'd have to sell my motherboard and RAM plus I'd have to put in a little extra money to buy it. Which CPU should I get?

 

[Ecky]

The 4790K on average overclocks a bit less than the 6700K, which as you've pointed out, also has higher IPC.

Between a 4790K and 5775c, I'd take the Broadwell CPU, if they were the same price. For me it's not insignificant that the 5775c draws significantly less power at the same performance level.

There are times when a 5775c actually outperforms the 6700K, despite lower clocks, due to its cache.

 

[photonboy]

i7-4790K

The CPU differences are insignificant to the real-world performance, especially in games, compared to the additional cost of building a new system.

(we're talking about 5% maximum performance differences in some cases, and generally NO difference for games. the i7-4790K for example is maybe 96% as fast as the 5775c if it's fully loaded but otherwise faster as it's single thread is almost 10% faster)

(It's also not clear if you have an existing CPU, or if Windows is installed. Otherwise why have the motherboard? If it's up and running switching sockets means buying a new copy of Windows as well plus reinstalling everything.)

 

[photonboy]

http://www.pcworld.com/article/2950704/hardware/intel-core-i7-5775c-review-the-unwanted-desktop-broadwell-has-one-neat-trick.html?page=4

"Even the strongest argument for Broadwell in a socket is very niche. In general use, it’s actually slower than the cheaper Haswell chip."

So...
The i7-4790K and i7-5775c where the two choices that didn't require a new motherboard and DDR memory. Between these two the only one that makes sense is the i7-4790K.

 

[Ambular]

What do you plan to do with it?

 

[Ecky]

Generally speaking, the 5775c is around the same speed as the 4790K, yes. I'd call them equal in performance; in some cases, the 4790K's clockspeed puts it ahead, and in others, the 5775c comes out ahead due to its cache:

(Examples of times when the 5775c comes out on top, despite its lower clockspeed)

On Newegg, it's currently $30 more expensive than the 4790K, which doesn't seem like much of a deal if they perform around the same, but consider that the 5775c performs the same as a 4790K, while drawing close to half of the power. To me, that might actually be worth $30 - to be able to cool it with a much smaller, cheaper heatsink, and to have the integrated graphics on tap (which might be more useful as DX12 matures).

Of course, I don't think either is a wrong choice. Just my 2 cents though.

 

[Ecky]

5775c will drop into your Z97-A though.

 

[Ambular]

The only thing I'd be concerned about with the Haswell and Broadwell processors is that there won't be any Windows 10 or DirectX 12 support for them. If you don't need those things and the cost is the same, then heck, you could almost just flip a coin between those two [ETA: performance-wise, that is] really...apart from Iris Pro graphics on the 5775c, the 4790k has better out-of-the-box single-thread performance, but not massively better.

 

[Ambular]

dx 12 support as in what- onboard ? Thats not a biggee to be honest.

Blargh, don't anyone mind me. I somehow keep associating pre-Skylake processors with Windows 7 and 8 and forgetting that they can run Windows 10, and it's Skylake that doesn't support the older OS's. Darn Microsoft messing up a perfectly good extended support policy.

So: the earlier processors have an advantage in that you can choose different Windows versions, but the downside of that is you miss out on DX12 if you don't go with 10, is what I was very incoherently trying to get at.

 

[Ambular]

I will be amazed if dx12 turns out worth a tin of beans, let alone the hill everybody keeps hoping.
Its all pie in the sky sales pitch I reckon.

I wouldn't be the least bit surprised if it flops. At some point, though, won't new games be requiring it to run?

 

[Ecky]

DX12 and DX11 will exist in parallel to each other. DX12 has a more complex software kit that allows developers to design games that more effectively uses hardware, but you probably won't see low-budget games using it due to its complexity. I imagine it will take off slowly, and allow for us to have better games on the same hardware, rather than make existing games run on lesser hardware.

Early DX12 games DO show a reduction in CPU bottlenecks, but it hasn't changed the pecking order at all. Developers are compensating by adding more effects and physics for the CPU to do.

 

[Ambular]

DX12 and DX11 will exist in parallel to each other. DX12 has a more complex software kit that allows developers to design games that more effectively uses hardware, but you probably won't see low-budget games using it due to its complexity. I imagine it will take off slowly, and allow for us to have better games on the same hardware, rather than make existing games run on lesser hardware.

Early DX12 games DO show a reduction in CPU bottlenecks, but it hasn't changed the pecking order at all. Developers are compensating by adding more effects and physics for the CPU to do.

Thank you for the information! And also my apologies to Moson1970. The thread derailment was unintentional.