Intel crashing. Faulty CPUs?

[i9CPU]

I have two motherboards:

• i9-14900K with MAG Z790 TOMAHAWK WIFI
• i9-13900K with PRO-Z690-A

After updating both to the latest BIOS, both CPUs keep crashing, even with:

• Default settings
• XMP disabled
• Intel power limits applied

What should I do now?

• Should I increase IA AC/DC Loadline?
• Are there other settings I should adjust?

I don’t understand how a BIOS flash could suddenly cause CPU instability. Also, the i9-14900K is now experiencing issues in Linux.

Any ideas on how to fix this?

---

[Tue Mar 18 04:40:53 2025] ------------[ cut here ]------------
[Tue Mar 18 04:40:53 2025] WARNING: CPU: 8 PID: 318 at arch/x86/kernel/fpu/core.c:448 kernel_fpu_end+0x30/0x40
[Tue Mar 18 04:40:53 2025] Modules linked in: raid6_pq(+) libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod ahci nvme libahci xhci_pci nvme_core xhci_hcd libata t10_pi crc64_rocksoft usbcore crc64 scsi_mod igc crc32_pclmul crc_t10dif crc32c_intel i2c_i801 crct10dif_generic crct10dif_pclmul i2c_smbus crct10dif_common usb_common scsi_common fan video wmi pinctrl_alderlake
[Tue Mar 18 04:40:53 2025] CPU: 8 PID: 318 Comm: modprobe Not tainted 6.1.0-31-amd64 #1 Debian 6.1.128-1
[Tue Mar 18 04:40:53 2025] Hardware name: Micro-Star International Co., Ltd. MS-7D91/MAG Z790 TOMAHAWK WIFI (MS-7D91), BIOS H.F0 03/06/2025
[Tue Mar 18 04:40:53 2025] RIP: 0010:kernel_fpu_end+0x30/0x40
[Tue Mar 18 04:40:53 2025] Code: 8a 05 3c 00 be 6f 84 c0 74 20 65 c6 05 30 00 be 6f 00 65 ff 0d 51 00 be 6f 74 05 c3 cc cc cc cc 0f 1f 44 00 00 c3 cc cc cc cc <0f> 0b eb dc 66 66 2e 0f 1f 84 00 00 00 00 00 90 55 48 89 d6 53 48
[Tue Mar 18 04:40:53 2025] RSP: 0018:ffffb4cc014c7b10 EFLAGS: 00010246
[Tue Mar 18 04:40:53 2025] RAX: ffffb4cc014c7b00 RBX: ffffffffc051c960 RCX: 0000000000000fe0
[Tue Mar 18 04:40:53 2025] RDX: ffff9390d8520000 RSI: 0000000000001000 RDI: ffffb4cc014c7b28
[Tue Mar 18 04:40:53 2025] RBP: 000000000002712f R08: 0000000000001000 R09: 0000000000000004
[Tue Mar 18 04:40:53 2025] R10: ffffb4cc014c7b50 R11: ffffb4cc014c7b58 R12: ffff9390d8520000
[Tue Mar 18 04:40:53 2025] R13: 00000000000275ea R14: ffffb4cc014c7b30 R15: ffffffffc0509160
[Tue Mar 18 04:40:53 2025] FS: 00007f21b24a4040(0000) GS:ffff93beff600000(0000) knlGS:0000000000000000
[Tue Mar 18 04:40:53 2025] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[Tue Mar 18 04:40:53 2025] CR2: 00007f36152da2e0 CR3: 0000000180692000 CR4: 0000000000750ee0
[Tue Mar 18 04:40:53 2025] PKRU: 55555554
[Tue Mar 18 04:40:53 2025] Call Trace:
[Tue Mar 18 04:40:53 2025] <TASK>
[Tue Mar 18 04:40:53 2025] ? __warn+0x7d/0xc0
[Tue Mar 18 04:40:53 2025] ? kernel_fpu_end+0x30/0x40
[Tue Mar 18 04:40:53 2025] ? report_bug+0xe2/0x150
[Tue Mar 18 04:40:53 2025] ? handle_bug+0x41/0x70
[Tue Mar 18 04:40:53 2025] ? exc_invalid_op+0x13/0x60
[Tue Mar 18 04:40:53 2025] ? asm_exc_invalid_op+0x16/0x20
[Tue Mar 18 04:40:53 2025] ? kernel_fpu_end+0x30/0x40
[Tue Mar 18 04:40:53 2025] init_module+0x123/0x1000 [raid6_pq]
[Tue Mar 18 04:40:53 2025] ? 0xffffffffc04d1000
[Tue Mar 18 04:40:53 2025] do_one_initcall+0x56/0x220
[Tue Mar 18 04:40:53 2025] do_init_module+0x4a/0x1f0
[Tue Mar 18 04:40:53 2025] __do_sys_finit_module+0xac/0x120
[Tue Mar 18 04:40:53 2025] do_syscall_64+0x55/0xb0
[Tue Mar 18 04:40:53 2025] ? exit_to_user_mode_prepare+0x40/0x1e0
[Tue Mar 18 04:40:53 2025] ? syscall_exit_to_user_mode+0x1e/0x40
[Tue Mar 18 04:40:53 2025] ? do_syscall_64+0x61/0xb0
[Tue Mar 18 04:40:53 2025] ? do_syscall_64+0x61/0xb0
[Tue Mar 18 04:40:53 2025] ? do_syscall_64+0x61/0xb0
[Tue Mar 18 04:40:53 2025] ? __rseq_handle_notify_resume+0xa9/0x4a0
[Tue Mar 18 04:40:53 2025] ? exit_to_user_mode_prepare+0x40/0x1e0
[Tue Mar 18 04:40:53 2025] ? syscall_exit_to_user_mode+0x1e/0x40
[Tue Mar 18 04:40:53 2025] ? do_syscall_64+0x61/0xb0
[Tue Mar 18 04:40:53 2025] ? do_user_addr_fault+0x1b0/0x550
[Tue Mar 18 04:40:53 2025] ? exit_to_user_mode_prepare+0x40/0x1e0
[Tue Mar 18 04:40:53 2025] entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[Tue Mar 18 04:40:53 2025] RIP: 0033:0x7f21b25a67d9
[Tue Mar 18 04:40:53 2025] Code: 08 89 e8 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d f7 05 0d 00 f7 d8 64 89 01 48
[Tue Mar 18 04:40:53 2025] RSP: 002b:00007ffd225e0d98 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[Tue Mar 18 04:40:53 2025] RAX: ffffffffffffffda RBX: 00005589cd2c4800 RCX: 00007f21b25a67d9
[Tue Mar 18 04:40:53 2025] RDX: 0000000000000000 RSI: 00005589a34844a0 RDI: 0000000000000005
[Tue Mar 18 04:40:53 2025] RBP: 00005589a34844a0 R08: 0000000000000000 R09: 00005589cd2c4fe0
[Tue Mar 18 04:40:53 2025] R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000060000
[Tue Mar 18 04:40:53 2025] R13: 0000000000000000 R14: 00005589cd2c47b0 R15: 0000000000000000
[Tue Mar 18 04:40:53 2025] </TASK>
[Tue Mar 18 04:40:53 2025] ---[ end trace 0000000000000000 ]---

[i9CPU]

Disabling Turbo-Boost stops the crashes. So I guess it's confirmed the CPU is faulty. Just not sure why it happened after BIOS flash.

[jbruceyu]

hey mate disabling Turbo Boost helping confirms that the issue is related to voltage regulation or power limits rather than a purely defective. If possible, try flashing back to a previous BIOS version that was stable. New BIOS updates sometimes introduce unintended instability. Set Loadline Calibration (LLC) to a moderate level (e.g., Level 3 or Auto). Adjust IA AC/DC Loadline – Try setting it to 0.9-1.1 to stabilize voltage. Manually set Vcore – Instead of Auto, try manually setting a reasonable Vcore (e.g., 1.25-1.35V). Check SA/IO voltages. If they were changed by the BIOS, they might need manual correction. Set PL1 = 125W and PL2 = 253W (or lower). Disable TVB (Thermal Velocity Boost) to see if it helps stability. Some BIOS updates include new microcode that affects stability. Intel Core 13th and 14th Gen Desktop Instability Root Cause Update

If the crashes stop after these tweaks, it's more likely a BIOS issue rather than outright CPU failure. If crashes persist even at stock settings, a deeper hardware issue could be at play.

-bruce

[i9CPU]

Hi,

I have already tested both CPUs under stock settings, but they continue to crash. I also tried adding voltage, but that didn’t resolve the issue.

At this point, I will be sending both CPUs back for return or replacement. Please provide the necessary steps to proceed with the RMA process.

Looking forward to your instructions.

[i9CPU]

Anyone?

Now I got a System Model Z790 AORUS ELITE X WIFI7

That started crashing as well after BIOS update.

Do I need to touch the LLC? It's crashing at auto