Question 11900k + Z490 refuses to boot with XMP

[Patishi]

Hi everyone,
I'm not sure if this is the best forum for this question, so please move it to a more appropriate location if necessary.
Long story short, I have Z490 Aorus Master motherboard, and I've been using the 10900k for 2 years. I decided to do a little side "upgrade" to 11900k (just wanted the PCIe4..), So I got myself a brand new 11900k and PCIe4 nvme drive. The installation went smooth, I upgraded the bios and installed windows..everything was ok.
Until I tried to load the XMP profile on the memory. I tried everything I know of, even tried to set the timings manually but nothing helped. I tried several RAM kits, same issue. It just won't post with settings that are not the stock JEDEC. It's only 3600 cl16..nothing too xtreme. The 11900k should be able to run this no problem.

I don't know if it's the CPU to blame or maybe the motherboard's Rocket lake support. I didn't see others complaining about the F20 bios and rocket lake.
I really didn't expect this. F20 bios should fully support Z490 with Rocket lake.
Maybe you can help me to find what's wrong? why can't I load the xmp profile? maybe I need to set something in the bios I don't know about? I tried to mess with all the settings I know of that could maybe effect this but nothing helped.

When running in stock JEDEC settings everything is fine, I even did a short RAM stability test and it is ok.

EDIT: And another thing I want to add, I replaced it back to the 10900k with the same F20 bios, and it loaded the XMP without any issues. So it can be the 11900k maybe not functioning properly or maybe the combination of the 11900k with the z490 motherboard/ F20 bios.
I would appreciate if someone got some light to shed on this.
Thx again.

 

[coercitiv]

My suggestion would be to input manual values for some of the more important memory OC settings. Off the top of my mind I would name:

• Memory Gear Mode
• System Agent Voltage
• VCCIO Memory OC Voltage

Rocket Lake brought these new "Memory Gear Mode" and the split of VCCIO into 2 separate voltages, so there's a chance the motherboard isn't configuring one of these correctly.

Start with Gear 2 mode and a System Agent voltage of around 1.25V. If your BIOS is showing controls for VCCIO Memory Voltage, you can set that as well to 1.25V, otherwise leave it on AUTO and try to POST after enabling one of the XMP profiles. If it still refuses to train, you can also try to disable XMP, set main timings manually, but instead of shooting straight for 3600MT/s work you way up from something very conservative like 2800MT/s and adding 100-200Mhz increments for each new POST attempt.

Keep in mind that each OC attempt that manages to take you successfully to the BIOS (without POST errors) is a great sign, it means the system was able to train the RAM for that particular OC.

That's all I can think of, though maybe some other member who actually owns a Rocket Lake CPU and Gigabyte board may chime in with more helpful advice.

 

[Patishi]

Thank you for the reply. I can't be sure but it indeed seems like the bios just doesn't update all the required settings.
I tried manually setting Gear 2 mode after applying the XMP but it didn't help.
can you please tell me what is the difference between VCCIO 1 and VCCIO 2? should I just set them both to the same value?

So basically the settings I need to put are:
3600 16-16-16-36-52
System agent - 1.25
VCCIO - 1.25

and that's it?

EDIT: sorry for the noobiness but I just never manually overclocked the memory, only through XMP.

 

[Patishi]

Well, I just gave up eventually. I spent two days trying to figure out what's wrong and I simply don't have the time or the will for troubleshooting. I just want my XMP and play games.
So I switched back to the 10900K.
I think maybe my 11900k is broken. I will try to return it.
Thx anyway guys.

 

[Dave3000]

The 11900k officially supports up to DDR4-3200.

Intel® Core™ i9-11900K Processor (16M Cache, up to 5.30 GHz) Product Specifications

Intel® Core™ i9-11900K Processor (16M Cache, up to 5.30 GHz) quick reference guide including specifications, features, pricing, compatibility, design documentation, ordering codes, spec codes and more.

ark.intel.com

The 10900k officially supports up to DDR4-2933.

Intel® Core™ i9-10900K Processor (20M Cache, up to 5.30 GHz) Product Specifications

Intel® Core™ i9-10900K Processor (20M Cache, up to 5.30 GHz) quick reference guide including specifications, features, pricing, compatibility, design documentation, ordering codes, spec codes and more.

ark.intel.com

It looks like you didn't win the silicon lottery for your 11900k to be stable at DDR4-3600 since you said your 10900k with the same motherboard didn't have issues with that DDR4-3600. Past DDR4-3200, even if supported by the motherboard, is the luck of the draw with 11th gen i9. You just got luckier with your 10900k than your 11900k especially since the 10900k officially supports a lower memory speed than the 11900k. If your 11900k can run reliably with DDR4-3200 with JEDEC timings then it's within spec. Have you tried lowering the speed to 3200 with manually setting it to JEDEC timings on the RAM and see if your CPU still has the issue?

 

[Patishi]

The 11900k officially supports up to DDR4-3200.

Intel® Core™ i9-11900K Processor (16M Cache, up to 5.30 GHz) Product Specifications

Intel® Core™ i9-11900K Processor (16M Cache, up to 5.30 GHz) quick reference guide including specifications, features, pricing, compatibility, design documentation, ordering codes, spec codes and more.

ark.intel.com

The 10900k officially supports up to DDR4-2933.

Intel® Core™ i9-10900K Processor (20M Cache, up to 5.30 GHz) Product Specifications

Intel® Core™ i9-10900K Processor (20M Cache, up to 5.30 GHz) quick reference guide including specifications, features, pricing, compatibility, design documentation, ordering codes, spec codes and more.

ark.intel.com

It looks like you didn't win the silicon lottery for your 11900k to be stable at DDR4-3600 since you said your 10900k with the same motherboard didn't have issues with that DDR4-3600. Past DDR4-3200, even if supported by the motherboard, is the luck of the draw with 11th gen i9. You just got luckier with your 10900k than your 11900k especially since the 10900k officially supports a lower memory speed than the 11900k. If your 11900k can run reliably with DDR4-3200 with JEDEC timings then it's within spec. Have you tried lowering the speed to 3200 with manually setting it to JEDEC timings on the RAM and see if your CPU still has the issue?

Yes, I did try to manually set 3200 and it doesn't work (which supposed to be officially supported). Something is definitely broken.. either on the CPU side or the bios side. I just don't know what it is.
The same F20 bios loads XMP just fine with the 10900k (trains 4000mhz C16 no problem) but with the 11900k it refuses to except any speeds above JEDEC specs (2133). I even tried to manually set the speeds and voltages but didn't help.
So I don't know what's wrong. With the memory at 2133mhz the cpu works flawlessly, no issues. If it was broken it shouldn't have work at all. I even put a little load on it just to be sure and it works just fine.

The only problem I have is to load the XMP profile. Is there anyone in here that have Z490 gigabyte board with F20 bios with 11900k? I am really desperate here. I paid 400$ for this CPU and I can't even use it.
The only way I can test if the CPU is ok is by trying it in a Z590 board and see if it works correctly. But I don't have a z590 board on hand.

 

[Patishi]

It seems that this guy also had a similar issue. Here is a quote from a post on reddit:

"my motherboard is z490 aorus xtreme my processor is 11700k. I was able to xmp my rams before I got the processor. After getting 11700k, my rams are not xmp and when I plug a sound card (x1) into the pci express x4 (lowest input) line, it doesn't work. When using a 10th generation processor, both xmp was working and my sound card was working. My rams are currently working at 2133mhz, even when I manually do the rams at 2200mhz, the system does not turn on."

(here is a link to the full thread: reddit link)

At least this assures me that there's nothing wrong with the CPU. I opened a ticket at Gigabyte's support but no answer.