New gaming rig - i5-6600 or i7-6700

[CHiLL]

I plan on building a new gaming rig in the near future, one that will not need upgrading for another 5-6 years.

My dilemma...do I go Core i5-6600 or Core i7-6700? I don't want the 'K' versions, as I have no intention at all to overclock.

Can anyone offer advice?!

[silent]

i'd go i7 if you need to do additional things like editing etc that need lots of cores and threads, but the i5 is the best gaming chip. the non k seies also overclock now on certain boards with a bios update and tweak.

i am also thinking of upgrading my z97 and 4690k at present but don;t know if its worth it!

[CHiLL]

i'd go i7 if you need to do additional things like editing etc that need lots of cores and threads, but the i5 is the best gaming chip. the non k seies also overclock now on certain boards with a bios update and tweak.

i am also thinking of upgrading my z97 and 4690k at present but don;t know if its worth it!

Every now and again I'll re-encode a video file or perform format conversions, but that has reduced severely over the past couple of years. I can't remember the last time I did anything like that.

[shaithis]

I'll throw the cat among the pigeons and say E3-1245 v5

[silent]

probably the i5 and spend the difference on a good GPU instead. or the xeon as an option.

i will also say that the AMD rigs i've built have been great for gaming in the past. and good value.

[MrJim]

I'll throw the cat among the pigeons and say E3-1245 v5

Nice choice, but the selection of motherboards is very limited right now...

https://www.scan.co.uk/search.aspx?q=c232+motherboard

[shaithis]

So, intel have stopped Xeons working in workstation boards with skylake have they?

[watercooled]

Yeah, sadly you need a different chipset for Xeons now. There are a few desktop-aimed Xeon boards in the pipeline though. http://www.anandtech.com/show/9948/c...ds-at-gigabyte

For gaming I'd say the i5. Even for video encoding, depending on the encoder you use, the i7's hyperthreading might not help massively anyway.

[EndlessWaves]

I don't want the 'K' versions, as I have no intention at all to overclock.

Intel have reverted to their old marketing strategy of making the K versions better as well as overclockable. So the 6700k runs at 4Ghz instead of the 3.4Ghz (3.7Ghz turbo) the 6700 runs at.

So unlike the 4770 & 4770k the 6700 is actually the next model down in performance from a stock speed 6700k rather than just a non-overclocking version of it.

[watercooled]

The 6700k has next to no turbo though, while the 6700 can do 3.7GHz on all cores (TDP permitting), and 4GHz on a single core. That few hundred MHz makes negligible difference in most applications.

The lack of turbo combined with the considerable efficiency drop-off the 6700k vs the i5 seems to show that 4GHz is a bit of a stretch for Skylake. Not that it matters much for desktop use, but it does make me think all the more that the 4GHz thing is a bit of a round-number marketing gimmick, same with the 4790k and for the 5GHz AMD FX CPUs. That, and regressing on clock speed would probably have people claiming the sky is falling despite the improved IPC, efficiency etc, so it's probably useful from a marketing point of view to have at least one CPU match the previous gen's clocks (even if not in turbo clocks).

[EndlessWaves]

That few hundred MHz makes negligible difference in most applications.

It's also all that separates the other models in the range. The 6500 to 6600 is 0.3Ghz in 4 core turbo for example, the 6400 to 6500 is 0.2Ghz.

considerable efficiency drop-off the 6700k

What considerable efficiency drop-off?

Looking at the tests SilentPCReview did of the two the efficiency seems pretty comparable. That is system power consumption but even if you're fairly conservative with the system power consumption you're generally talking single digit percents more power use than performance.

They don't give the manufacture date of the two CPUs they tested, but as they reviewed the 6700k first it's likely to be earlier production.

[watercooled]

It's also all that separates the other models in the range. The 6500 to 6600 is 0.3Ghz in 4 core turbo for example, the 6400 to 6500 is 0.2Ghz.

Which is why I often suggest not immediately going for the one with the highest number on the box, as there's not always much point in doing so. There's just nothing overly special about the k given the higher price, unless you need the OC ability.

What considerable efficiency drop-off?

The bit you cut out of my quote shows I was comparing to i5 clocks (they use the same die). I assumed the first review I read might have had a bad sample because of the striking difference in power consumption between the two, but it turns out it's just how it is according to the measurements I've seen. It stood out to me as more of a delta than previous generations; the Skylake i5 being one of the lowest-power i5s, and the i7 one of the highest. And that's even from similar non-maxed workloads (e.g. gaming) which rules out SMT as the only cause because of increased utilisation.
http://www.tomshardware.co.uk/skylak...-33276-11.html
http://www.anandtech.com/show/9483/i...h-generation/6

As I said though, diminishing returns is nothing unique to Skylake - all processors have an efficiency curve of sorts which means beyond a point you'll get rapidly diminishing returns in terms of performance per joule spent. And it wouldn't surprise me at all given the low-power improvements in Skylake if the 14nm process isn't as geared towards high-power operation.

I gave the 4790k as another example of this phenomenon, its power consumption being markedly higher than the 4770k before it, even given the maturity of the 22nm node at the time.

Edit: But having said that, the i5's clocks aren't all that different to the i7 anyway, so there could be something else in it. I'm not too sure what though as I know there are differences in SMT, but these differences exist in lightly threaded workloads too. The i7's power just seems strangely high relative to their other processors. But as far as the OP is concerned it's not terribly important, just something I'm curious about.

[chuckskull]

I wouldn't go for i7 unless you've already bought a top end GPU. The GPU will make far more performance difference than HT ever will. Spend your money there first you'll get a much better return. If you've got a 980ti and money left in the budget only then would I consider an i7.

[CAT-THE-FIFTH]

So, intel have stopped Xeons working in workstation boards with skylake have they?

Yeah,and the Xeon E3 1230 V5 is still not available in the UK:

http://ark.intel.com/products/88182/...Cache-3_40-GHz

The RRP is slightly above that of the Core i5 6600K.

I plan on building a new gaming rig in the near future, one that will not need upgrading for another 5-6 years.

My dilemma...do I go Core i5-6600 or Core i7-6700? I don't want the 'K' versions, as I have no intention at all to overclock.

Can anyone offer advice?!

You already have a Core i7 2600K - if I were you I would hold off. Zen should be out at the end of the year and Kaby Lake.

[watercooled]

You already have a Core i7 2600K

I concur with this TBH - unless you know you're having performance issues with your current CPU I'd just stick with what you have and put the money towards something more useful like a GPU upgrade. You don't have to bin your entire system and start over to get the most out of games.

[Bonebreaker777]

Zen should be out at the end of the year and Kaby Lake.

Me want tests! Me can't wait. Me curious.