Safe voltage and temps for haswell e 5820k and haswell 4690k?

I got a 5820k this last saturday and my little brother a 4960k, we are both wanting to overclock to 4.6ghz if possible and both have after market coolers. nepton 140 and hyper 212 evo respectively. I haven't overclocked since sandy bridge and I know 22nm cant take as much voltage as 32nm, and they use tim instead of solder on the heat spreader now, so I'm not sure what is a safe voltage and temperature anymore. I figure IBT and p95 26.6 are still good to use, but can anyone more knowledgeable than I tell me what voltages and temperatures to stay under

There really is no particular number.

I can tell you that I try to keep my system below 1.3v and 70 degrees for a 24/7 overclock.

But someone else might be comfortable with 1.35v and 80C.

I can tell you for certain that anything around 1.4v with temperatures in the 90s is very very bad.

For me as the 5820k can produces heat very quickly (it's still a soldered chip by the way) I tend to aim for 70s as the ceiling when stress testing. That's easily achievable if you're sensible with the voltage and OC. 4.5 GHz is a good upper limit on the 6 core with say 1.3v max though I personally run 4.25GHz as a good enough OC but my chip is proving to be quite good as I'm only running 1.14v on it.

Also set the uncore ratio to a lower setting for stability. At 4.25GHz my uncore OC is 3.5GHz and I've not had any stability issues. By the way I'm using DDR4 3000Hz memory which when selecting the RAM profile sets the BCLK to 125MHz x 34 ratio = 4.25GHz (uncore x 28).

My chip will go higher but as my aim was to run FO4 @ 3440 x 1440, 75fps capped and stay in the 40s C on the CPU i'm achieving that at 4.25GHz. Plus a 980 Ti of course.

I'm using a 240mm AIO with 2 x Sp120s just for reference.

Prime95 is not so popular as it really stresses the CPU but people still like to use it. I like AIDA64 myself as when running the built in stress test (60 C max) you can graph all sorts such as temps, fan rpm, voltages etc. at the same time.

I got 4.4ghz at 1.31V(I think I cant do 1.3 but its at 1.31 cause entered and too lazy to change) with AIDA64 it hovered around 70C on my 140mm AIO cooler, could get lower temps if I set it to run full pump and fan speed 24/7 but dat noise. I may try 1.35V and 4.6ghz and see if the temps stay 78 or below on aida, since in game they'll be lower than that anyway. but for now 4.4ghz and 13937 fire strike score is good enough. Maybe this weekend I'll go 4.6, maybe. GOnna try for 4.4 on the 4690k this week too. Same voltages safe on normal haswell too or higher/lower due to core count?

My only comment is that when pushing those sort of speeds on the high ends PCUs you ideally want a 240/280 rad with twin fans so you're not pushing the limit on the AIO constantly. As a result you run the fans and pump more slowly assuming you have pump voltage control.

My 240mm AIO CPU cooler is based on a generic Asetek gen 4 pump which via AIDA64 I can see runs at a constant ~1800 RPM and is not audible over the system fans. My fans run at ~800 RPM idle, ~1000 RPM gaming & ~1250RPM stress testing in AIDA64.

Prime95 small FTTs whcih is a killer test which I wouldn't personally run for very long if at all gets my 6 core up to 70 DegC and the fans run at a very noticeable 1650 RPM.

The voltage I would say is at the higher end of what I'd be pushing, but I'd definitely be looking at replacing that 140mm AIO with a 280mm or even a 360mm AIO in the near future as 140 I don't consider good enough for overclocking. I use a 280mm AIO from Cooler master and that maintains my system at 25°c at idle and it never sees above 50°c under load (haven't benchedmarked it with any CPU benchmarks but when gaming I never see above 50°c). Mind you the room it is in has an Air-conditioner vent in it and it's set to 22°c year round (because Australia). Edit, I'm running a 4790K @ 4.7ghz and was stable at 1.2v but I upped it to 1.25 just for safety.

Eh it stays 70C or under on the stress test so I'm not too concerned about the temperature. My 140mm rad performs within 2C of an h100i. I may try to get a bit lower voltage but I know I dont have the best overclocker ever but haswell E doesn't oc as well as normal haswell anyway cause more cores and power used. Still 1.31 isn't too bad, 1.35 is supposed to be the safe limit according to tomhardware, so long as it stays a decent temperature I wont complain. Its not like I have room for a 240mm cooler like the h100i anyway in my case right now.

I dont mine the noise or fans running fast. Even in aida it didn't run at 100%. In year or two when I can afford a bigger case and fit a bigger cooler I'll get something better but it stays under 75C in the stress test so in game it should be even better.