TURNING OFF ONE PARTICULAR CORE ON A C8/T16 Core i9-9900K SRELS

[GeorgettaCZ]

Hello geeks,

 

Well, I came accross an older Core i9-9900K that seems to have one failed core. In particular the 6th core seems to cause crashing. I bought this CPU from one guy who told me, he has an ASUS Z370 board with broken CPU socket (some pins were accidentally bent and eventually fell off of the socket when tried to be levelled back) and that this CPU on this crippled board only shows 3 cores, if it boots at all sometimes. So I thought, hmmm, chances to boot a healthy CPU on a broken socket are low but still, it can happen that the motherboard somehow reads the CPU just enough to POST. The guy even posted me with some puictures from installed Windows where it showed 3 cores, no HT. And since I did not meat many borken i9s I thought, alright, maybe the CPU is fine and it would be a good buy!

 

Now, when I put the CPU in my known-good Gigabyte Aorus Z370 Ultra Gaming (latest F16b BIOS) + 2x8GB Samsung OEM DDR4@3200 and nothing else, the set boots fine, the CPU gets recognized and all seems okay. Then I added 1 M.2 SSD and a bootable Win11 USB... booted,...and crashed to BSOD with HAL_INITIALIZATION_FAILED.

 

So I ran bootable USB with MemTEST86 and soon as it started in default mode, it showed many errors and eventually failed during too many errors detected. So first I replaced the RAM with another dual channel set of braand new 2x16GB Patriot Viper Steel. Same result as the pictures show. So I did some more testing but with only one single core enabled in the MemTEST86 and it went fine.

 

So I went to BIOS and enabled only 5 cores of 8. I ran the MemTEST86 again...and, though only 5 cores were enabled and the program showed them as 5 active, the teesting failed soon again, pointing to core 6 again.

 

So I went to BIOS and enabled only 4 cores of 8 and disabled hyper thread. I ran the MemTEST86 again...and, though only 4 cores were enabled and set active, the teesting failed again, pointing AGAIN to core 6.

 

So before I throw the CPU in the bin, I thought if there is a way to mod the BIOS file and disable the 6th core directly. Any ideas??

 

Regards, George

[RONOTHAN##]

14 minutes ago, GeorgettaCZ said:

So before I throw the CPU in the bin, I thought if there is a way to mod the BIOS file and disable the 6th core directly. Any ideas??

 

AFAIK, that functionality to enable and disable specific cores was not introduced until 10th gen. There shouldn't be a way to do this on 9th gen. 

 

You can try clocking it down to see if that helps, 9900Ks might have the ability to do per core ratios so you can just underclock core 6 to see if it helps at all. 

[Bob__]

what about just making the core unuseable (0.1 ghz)

11 minutes ago, RONOTHAN## said:

You can try clocking it down to see if that helps, 9900Ks might have the ability to do per core ratios so you can just underclock core 6 to see if it helps at all.