Very random freezing - dead CPU?

[SubWoofer]

Hey,

 

I am experiencing very random freezes for about 10 months now, and can’t figure it out.
I swapped motherboard, GPU, SSDs, operating systems...
Ram is ok, according to Memtest. I also tried with only one and two sticks.
Temperatures are ok and nothing is overclocked.

 

All the hardware that cause freezes (i used them interchangeably without good results):
OS (all 64bit):

- Win 7 Pro

- Win 10 Pro

- Hackintosh El Capitan and High Sierra
OS SSD:

- Samsung 850 EVO 250GB

- Crucial BX500 480GB
CPU: i7 4790k
CPU cooler: Noctua NH-D15
Mobo:

- Gigabyte z97x SLI

- MSI H81M-E33 (both on latest BIOS)
RAM: 32 GB (4 x 8 GB sticks of the same ram)
GPU:

- Nvidia GTX 970,

- Radeon HD 5540, integrated in CPU
PSU: XFX TF 550W 80+ bronze

All other storage drives are in a separate server.

 

There is no BSOD or anything else apart from PC suddenly appears unresponsive. Freeze can happen 15 min after the boot, or not at all the whole day. Usually somewhere in between (0 to 10 freezes during the day).

It's seemingly unrelated of operating system, boot time, programs in use, intensity of use. I ran Valley benchmark all night, and it was fine, but it can freeze on idle…

I mainly use High Sierra (because of music production), but as i went trough event viewer on windows, the events just stop at the freeze, and events prior are random and seemingly unrelated.

 

I haven’t replaced CPU or PSU. Should I?
What else can i try?
I don’t want to take it to repair shop, as i want to get to the bottom of this.

 

Thanks!

[homeap5]

Something may be wrong with motherboard - it may be just bios settings or faulty hardware.

 

Also - try to use XMP profiles (or disable them if they're already set).

[SubWoofer]

1 hour ago, homeap5 said:

Something may be wrong with motherboard - it may be just bios settings or faulty hardware.

 

Also - try to use XMP profiles (or disable them if they're already set).

I already tried with two different motherboards. Default BIOS on both and XMP on the latest one.

[homeap5]

So ram is the only answer then. Even if you test it - still may have some problems. You have two different ssd, two motherboards etc. So if we eliminate everything (what about psu?) ram is the only logical answer. Anyway - checking psu is with to try.

[SubWoofer]

1 hour ago, homeap5 said:

So ram is the only answer then. Even if you test it - still may have some problems. You have two different ssd, two motherboards etc. So if we eliminate everything (what about psu?) ram is the only logical answer. Anyway - checking psu is with to try.

I now swapped PSU, and will wait a bit. Than i'll swap RAM and wait a bit...

How likely it is that the CPU is doing this?

[homeap5]

1 hour ago, SubWoofer said:

I now swapped PSU, and will wait a bit. Than i'll swap RAM and wait a bit...

How likely it is that the CPU is doing this?

Imo very unlikely.

[SubWoofer]

21 hours ago, homeap5 said:

Imo very unlikely.

I think so too, but maybe we are wrong...

 

1. I swapped PSU with another 500W, and removed GTX 970, and ran graphics from CPU.

Doesn't work.

 

2. I than swapped back to XFX PSU and integrated graphics, and swapped RAM with two 2GB modules i had around.

Doesn't work.

 

So really the only thing i haven't swapped is the CPU...

Is there anything else i can do to make my system stable? Underclock / undervolt CPU?

 

I ran a bunch of tests from https://www.ultimatebootcd.com and all was fine. No freeze all night and all tests passed.

[homeap5]

Underclock cpu - no. Only if you have it overclocked. Undervolt don't help with stability. You can try raise voltage a little, but seriously - I'm out of ideas. Normally I would say that is something in system, but if you have lot of systems, then it's not the reason.