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AI Suite doing strange things with Corsair DDR4 2666 (C16) memory

jonstatt
Level 7
I have reported this issue to Asus support but I don't think I am being understood.

X99 set-up and working with a 5820K processor and Corsair 16GB (4x4) of DDR 4 memory.

The Corsair memory has two XMP profiles. One for 2666 which is supported. And one for 2800 which is not.

In AI Suite 3 when running the 5-way optimisation routing, it chooses the 2800 profile but implements it totally wrongly. The 2800 profile actually should be pushing a 125MHz strap. But what happens with AI Suite, is it leaves the strap at 100, wrongly sets the speed to DDR 2400 but correctly sets the timings of 2800 and the voltage of 2800 (1.35V). It is completely messed up. If I force the timing to 2800 in the BIOS it is unstable, because 2800 with this memory requires the 125 strap for stability. In fact AI Suite should choose the lowest XMP profile, not the highest by default (or at least give a choice)

Additonally AI Suite 3 reports the DRAM frequency as 3.1GHz no matter what it actually is. Of course MemTweakIt shows it correctly.

Incidentally currently running the 5820K at 4GHz which is so completely easy. 4.2GHz using CPU level up works to a point as it runs for normal operation, but I get a BSOD after a short time in Prime95 28.x. CPU temps are nowhere near limits although its hard to be sure as AI Suite reports the CPU temperature about 10 degrees lower than the latest version of CPUID Hardware monitor.
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Chino
Level 15
AI Suite reports the CPU temperature in a different way than your normal temperature monitoring program. Also running two monitoring programs at once isn't recommended as it causes polling issues. It's one or the other.

What you can do is take the voltage that AI Suite used for your overclock and input it manually in the BIOS. Then setup your RAM using the XMP of your choice.

jonstatt
Level 7
Thanks. That is what I will have to do. I did some more investigations and found that it's the CPU Level UP function in the BIOS that is broken. Another weird thing is if you use CPU Level Up and then manually change the DRAM timing, Speedstep stops working! There are some really weird interacting aspects. So I just need to do everything manually and hopefully avoid all of that.

Chino
Level 15
It's not broken. It just happens sometimes when your CPU needs a tag more voltage than what the automatic scaling routines establish. In such cases, manual adjustment will be needed.

As for Speedstep, it might have been disabled during the CPU Level UP process to provide better performance.

Chino wrote:
It's not broken. It just happens sometimes when your CPU needs a tag more voltage than what the automatic scaling routines establish. In such cases, manual adjustment will be needed.

As for Speedstep, it might have been disabled during the CPU Level UP process to provide better performance.



When I say broken I meant the fact the Level Up auto-chose the XMP 2800 profile of the RAM but then chose DDR 2400 as the frequency instead, but with the 2800 DRAM timings and voltage. The speedstep issue is weird because in the CPU settings, speedstep, turbo are enabled and C1E is still Auto. In fact even if I put the level up settings and everything else back as they were, I cannot get Speedstep to start working again unless I load BIOS defaults.

jonstatt
Level 7
I found out what is happening with the Speedstep...actually its the C-state problem. When you do level up, it does so while leaving C1E and C6 enabled. But when you then change anything subsequently in the BIOS it forcefully disables C6. Changing C-States option from Auto to enabled at least allows C1E to work again...but the voltage will not reduce meaning the high VCore is there 24x7. I will post a separate topic on this rather than confuse the original bug I was trying to report which was the wrong setting of DDR 2400 when following an XMP 2800 profile.