Core i7 4790k or i7 5775c?

[adavid]

I will be building a new gaming PC in a week or two, and I was planning on getting the 4790k, but then I heard that the 5775c has officially launched, so I was wondering which one is worth my money better, because from reviews that already exist (wow websites are fast), they all say that the CPU part of it it not that amazing at stock compared to the 4790k, but the integrated GPU is killer.
all of the benchmarks I'm seeing on the web are stock benchmarks, and I plan on overclocking with a NH-D14, I don't know which one to go for...

So which one is better when overclocked? most people are getting 4.7GHz with a D14 with the 4790k, but I have no Idea what the new one is capable of...

I do have a few FYI notes:
1. I don't care about power consumption, so that extra 30w that the 4790k takes is not a big deal
2. I am pairing it with a GTX 970.
3. As I said, I am overclocking with a Noctua NH-D14 with the stock fans.
4. I am not just gaming, I will be Streaming and Rendering, that's why I'm going for the i7 and not the i5.

I do have a few other questions that are related:
1. will the new CPU work with the MSI z97 Gaming 5? because I'm hearing that you need a BIOS update out of the box so the motherboard will support Broadwell-K, and I dont have a spare CPU to put in it just to update the BIOS, nor a way to update it with someone else's CPU.
2. what can I (not exact, there is a chip lottery) expect from overclocking the 5775c? I saw this article about someone getting 5GHz on air with the 5775c, is it real?
link: http://www.kitguru.net/components/cpu/anton-shilov/intel-core-i7-5775c-broadwell-overclocked-to-5ghz-with-air-cooling/
3. Is the beefed up iGPU a big deal, or should I not care about it, because there is 128MB of L4 cache on-board, and I dont know if its related for the GPU only, or for the CPU as-well, and that will also be a big help in rendering...

 

[drixkarasu]

The 4790k is a higher end CPU with a weaker iGPU, if you are going to use a discrete GPU just get the 4790k.

 

[adavid]

The 4790k is a higher end CPU with a weaker iGPU, if you are going to use a discrete GPU just get the 4790k.

but what about overclocking? if the 5775c can overclock to 5GHz on air, combine that with a 15% IPC benefit, it can outperform the 4790k by a-lot...

 

[hamzahfelix]

I would also get the i7 4790k. As u said, the extra 30w that 4790k takes is not a big deal. And the superior iris pro igpu of the 5775c will be irrelevant as you already have a discrete graphics card.

1. Broadwell cpus will require a new bios update on the z97 boards. Should you go with the 5775c, you must check with the salesperson before you make the purchase to see if the board is already compatible out of the box, or if there's a way to flash the new bios onto the mobo without inserting a cpu. The 4770k will require no such hassle, as z97 boards are made to work out of the box with hashwell refresh.
2. As the tdp of the 5775c is lower than the 4770k, it will come as no wonder that the 5775c will have slightly more oc headroom compared to the 4770k with better chip lottery. Thus a higher clock speed like 5.0 Ghz is certainly possible.
3. The stronger igpu is irrelevant to any who possess a discrete gpu.

 

[adavid]

I would also get the i7 4790k. As u said, the extra 30w that 4790k takes is not a big deal. And the superior iris pro igpu of the 5775c will be irrelevant as you already have a discrete graphics card.

1. Broadwell cpus will require a new bios update on the z97 boards. Should you go with the 5775c, you must check with the salesperson before you make the purchase to see if the board is already compatible out of the box, or if there's a way to flash the new bios onto the mobo without inserting a cpu. The 4770k will require no such hassle, as z97 boards are made to work out of the box with hashwell refresh.
2. As the tdp of the 5775c is lower than the 4770k, it will come as no wonder that the 5775c will have slightly more oc headroom compared to the 4770k with better chip lottery. Thus a higher clock speed like 5.0 Ghz is certainly possible.
3. The stronger igpu is irrelevant to any who possess a discrete gpu.

So what you are saying is that at stock the 4790k is better because of the higher clock speed, and that the Broadwell one will require more work to get functioning, but it will potentially perform better, as well as having a stronger iGPU if something goes wrong?

 

[Joseph DeGarmo]

The i7-4790k has better L3 cache, but the i7-5775c has this new L4 cache I've never seen before. Can anyone shed some light on this?

 

[hamzahfelix]

Broadwell is just a toc in intel's grand scheme of cpu release, meaning it will offer only better power usage compared to hashwell. Thus overclocked higher, it will still not exceed hashwell performance wise. Skylake is when performance will definitely increase, albeit probably only by 15-20% over hashwell and broadwell.

 

[Moonstick2]

The L4 cache serves as fast memory for the iGPU. It won't affect the performance of the CPU, so it's only an advantage if using integrated graphics.

 

[hamzahfelix]

Sorry I meant to say tick, not toc.

TDP is thermal design power. Better tdp, less power usage and thus lower heat output. Thus the 5775c will be able to take more power for overclocking before it began to throttle when compared to the 4770k. Having said that, I doubt with even higher oc the 5775c will outperform the oced 4790k by more than 5%.

At stock speed both the 5775c and 4790k will be similar, in spite of the lower clock speed of the 5775c at stock. Clock speeds are comparable for performance ONLY for the same cpu generation. So in this case it is not comparable.

 

[DubbleClick]

You can't overclock each I7 5775c to 5ghz. Even the test sample didn't manage anything but booting into windows, with a vcore of 1.55v - 0.3v more than recommended maximum!
The I7 4790k already had a 6.2ghz overclock under water before it launched - most struggle with 4.9-5.0ghz.

The ipc gain is about 5% too, not the 15% that are likely for skylake (over haswell). After all the I7 4790k is still the faster cpu.