Trying to figure out safest overclock - RTX + CPU

[Glazarus]

So I've overclocked both my CPU and RTX 2080 ti Strix to a level where I feel they hold without making my rig take off. 

However, I'm limited to only a 750W power supply, which means I'm afraid the wattage is gonna hit past that if there's any workload that uses both the CPU and GPU at the same time. 

I have a wattage-meter so I can see the drainage from the wall socket, but the biggest problem is that I don't have any stress tests that test the CPU and GPU at the same time. I use Intel's overclocking manager and the Asus GPU tweak II. 

 

So far, if I put my CPU at 4.0 and cache to 2.8 and stress test it, the meter shows around 500-600w, but I guess that's only for the processor. When I play a game like Metro Exodus with everything on highest, RTX on ultra and in 4K DLSS mode, I hit around 530w with the processor only at 30%. I would imagine that if the processor went up to 100% and the GPU also around 100%, that would seriously max out beyond my 750w. Question is, will it ever do that? Is there ever an occasion where both the GPU and CPU works at the same time at 100%? It seems that every task is either using the GPU or CPU primarily, but never both. 

 

Question is, how high can I go on my current rig? Theoretically, that is. At the moment, I've only dared to set my CPU at 4.0 clock and cache to 2.8, while my 2080 ti is set to:
1750 clock

Nothing added on the memory clock

Fans to 45 

Power level to 120

 

Metro crashes if I go higher. I tried setting the 2080 ti to 1800 clock, but that crashed it even more times. I've read however that Metro seems to crash because of overclocking, so I'm not sure if it does so because my overclock fails or is unstable or if the game doesn't work with overclocking. When I looked at JayzTwoCents's overclock of the Strix 2080 ti, he just blasted it up to 1800 core clock, maxed out memory clock, power level to 125 and fans to 100 percent and it was no biggie. He didn't touch the voltage at all, which feels safe, but wouldn't such an overclock just be a very high risk if my processor has a high wattage count when working? I also seem to see in BIOS that my RAM is set at 2800 instead of 3600 MHz and I don't know what that's about? 

 

I'm not very experienced at overclocking and I'd rather have a stable overclock than winning any overclocking contests, but since I have both a CPU and GPU that is meant for overclocking, then it's just a waste of money not to do it. 

But I'm not sure what is safe for my system. Temperature seems to work fine, I have a lot of Noctua fans pulling some air through the rig, and the Kraken on the CPU with two Noctua fans blowing at the radiator on the top ceiling. 

 

Need some advice here

 

Here's my rig:

intel Core i9 7960X 2.8 GHz 22MB
Corsair 64GB (4x16GB) DDR4 3600MHz CL18
Seasonic FOCUS Plus 750W Gold
WD Gold 10TB 7200rpm 256MB (Main big storage)
3 WD Gold 6TB 7200rpm 128MB (BIOS RAID for 4-6K footage editing and color grading)
Kraken X52 (On the CPU to the radiator at the top with the two Noctua's blowing upwards)
ASUS WS X299 SAGE
ASUS Thunderbolt EX 3 ASUS RTX 2080 ti Strix
Fractal Design Define XL R2 Black Noctua NF-A14 140mm PWM (one at the bottom, one at the rear and two in the front) Noctua NF-A12x25 PWM (two on the radiator) Windows 10 Pro Swe 64-bit OEM Samsung 970 PRO 1TB (Main boot Drive with Windows 10)

[Glazarus]

UPDATE: I enabled XMP but disabled Asus multicore handling. Did a stress test at my 4.0 GHz core and 2.8 Cache frequency in Intel Extreme Tuning and the system seems to be stable. However, this is without the 2080 ti overclocked (only Strix default overclock at 1650 MHz.

 

So where to go from here? Not sure how stable I can overclock my GPU without overloading the whole system on my 750w. Is it possible to do the JayzTwoCents-overclock safely, or would I need a 1000w power for that?