Having problems with i5 6600k overclock....

[rogermorse]

I don't want to use the 'auto' overclock. Also the auto overclock I think made me crash witcher 3. I played a lot in the last days (I mounted the new pc 3 or 4 days ago), rocket league and some other games, but today I had one crash in witcher 3 which is quite a heavy game. I assumed it was because of the cpu overclock (game froze).

I checked online what were the recommended voltages etc. Now I am at 4.5 Ghz with offset voltage +0.05. Max voltage recorded is 1.31 but every stress test brings the cpu temp instantly at 88 degrees (celsius). This is weird, I have 29 degrees at idle (it's summer and it's hot so it is pretty good) and with 'normal' games (not witcher 3) the temps were always low as well. I don't see why the stress test should bring the temps sky high like that.

I am not sure I need overclocking (I guess the 6600k at stock speed, with turbo mode, should be capable of handling all games without problems), but more power is always welcome (for other things, like encoding or similar).

My current system:

i5 6600k
asus z170-a
2x8GB corsair dominator 2666
zalman CNPS 9900
corsair 850w 850i

In the meantime I'll keep the system like this and see if witcher freezes again. If it does i'll test stock speeds till I find a good config for the overclock.

[Air]

Well, overclocking is mostly trial and error. If it doesn't work, then pull things back a bit.

Also, how far you can overclock while keeping stability depends on your CPU cooler and luck on part of your CPU. Not all CPUs, even of the same model, are equal in overclocking potential(popularly known as the "silicon lottery"), an overclock for one i5 6600k might not work for yours, so don't just copy overclock settings you see on the internet.

[_I_]

oc test repeat until stable

basics
start at stock cpu multi and core voltage

test with prime95 or ibt for about 15 minutes, watching temps with hwmonitor
i5 max is 90c, aim for around 80c max to give some headroom

temps low and stable = raise cpu multi
temps low and unstable = raise core voltage .05v
temps high and stable = lower core voltage .05v
temps high and unstable = go back to last stable and stop

[rogermorse]

yeah I know that overclocking can be tricky but I thought skylake was as easy to overclock as sandy bridge. My old i5 2500k stayed easily at 4.5 GHz without any effort (I used a 'recipe' from someone else and didn't have to test much). I also had the same cooler.

The zalman 9900 is a pain to install. I can never be sure if the cooling paste spread correctly or not....given that in idle I have less than 30 degrees with fan at 800 rpm tells me that the paste should be actually alright.

Also the voltage thing works with manual voltage. Should I use manual voltage? Everybody says to prefer offset voltage because manual completely erases the clock jump (from idle to full load). And I don't know how would it work with offset (people say to use a step of +0.05) variations.

I am now on normal default mode (turbo mode reaches 3900 by default) which is not a real overclock. I will stay for some days like this and see what happens. If I don't really need extra power (in games I doubt I will need it), I can stay like this till I change cpu cooler and then try overclocking when I am sure that the paste is correctly spread (I would like a h110 GTX....I know people don't really say nice things about those water cooling kits, but at least they are easy to clean and very easy to mount).

[rogermorse]

yeah with the default turbo mode on and cpu reaching 3.900 I got around 80 degrees max and max voltage of 1.28. Maybe the temperature is still quite high to be a default clock. I'll try without the cpu fan resistance (there is a resistance on the cpu fan cable to make it slower and quieter, but with the other 15 2500k as well I always used it without any temperature problems).

[_I_]

look at teh core temps in hwmonitor
if they are more than 5c apart redo the paste

1/2 pea or grain of rise sized dot in the cernter of the cpu is all thats needed

[𝕙.𝕓𝕒𝕣𝕜𝕒𝕤]

The zalman 9900 is a pain to install. I can never be sure if the cooling paste spread correctly or not...

Use Cool Laboratory Liquid Pro and you dont have this problem aside from better temps.

[rogermorse]

right now in desktop hwinfo64 shows me

core 0 - 28
core 1 - 29
core 2 - 29
core 3 - 28

does that mean that the paste is ok? room temperature is about 26 degrees.

also I have seen a video in which they tested all kinds of 'techniques' to put paste....and benched all of them (grain of rice, peanut size, cross shape, z shape, extra paste party, etc) none of them actually changed anything in the temperatures, even putting A LOT of paste gave the same exact results (I think it was linustech youtube channel). The only bad solution was putting too little paste on the cpu. That's why this time I tried to put more than last time. But as I said the zalman is so difficult to put, when you press the paste you can't keep it still while you center it on the holes so I am always afraid to spread the paste all around the heatsink....though the idle temperatures are quite nice, I think. weird that overclocking gives me problems right away.

[_I_]

idle is meaningless

how about load temps?

run prim95 or ibt for about 5 minutes and check

[rogermorse]

yeah it was a max of 80 degrees, so basically normal. Though it's only 3900....I should have 80 degrees in full load with 4600 .......

[Vox]

If memory serves me well, offset will cause the voltage to spike, causing higher temps, you'd be best using manual mode and around 1.30v

[rogermorse]

but doesn't manual mode completely eliminate the clock change? I tried manual mode with 4.6 ghz and the clock didn't want to settle down in desktop environment....always stuck on 4.6. am I right ?

[Vox]

That sounds like a speedstep issue, you can enable it in the bios, so the clock will lower under load. My guess also is that offset is causing the freezing because of the voltage changes.

Also to add, 4.6 on a i6600k requires much more voltage to keep it stable, around 1.35/6, where as 4.5 can do around 1.29/30

[_I_]

if you are overclocking its best to disable turbo and c1e to stop it from changing speeds for you