X99 (Taichi) - only seeing 48 of 64GB installed

First up, these are the memory configurations for X99's:




Secondly, if you haven't yet already flashed the BIOS to P1.40 you should. But first look at the lower middle edge of the board and you'll see two stickers covering the BIOS chips. On the stickers is the BIOS is printed the BIOS rev that it was flashed while during production.

Too, you can look at the opening page after entering the BIOS and the current revision will be displayed there too.

Use Instant Flash from within the Tools tab of the BIOS to upflash. It's IMO the safest method of doing so.

X99's are very finicky concerning memory.

Too, concerning these are sticks listed on ASRocks own Memory QVL, consider mem manufacturers regularly change DRAM chips on sticks/Kits that may match the primary timings yet completely hose secondary and tertiary timings from one binned chip to another even while keeping the same part number.

Unfortunately Kingston doesn't yet list the Taichi in their compatibility tool. Yet I do see the HX430C15PB3K4/64 kit listed, that I looked at, for the X99's they do list. That's a good start.



I'd say get your BIOS to P1.40, Reset to UEFI Defaults twice, power down, use ONLY two sticks in the proper slots, let it boot to their JEDEC 2133 speed, shut down and install the remaining two sticks and give it a whirl.


Please, post back your results if you would.

No. Here I'd say pull the CPU and look closely in the CPU socket for misplaced pin(s). Use a magnifying glass as the amplify any possible irregularities.

Also, the CPU cooler isn't/didn't get tightened to firmly did it?

Odd D1 shows highlighted in Red in that System Browser pic.

IIRC it should show as Yellow like the other one.



Lemme as parsec here. He has an X99.

I discovered something about this model of memory that I will discuss later, but first...

Have you run the memory at stock/Auto speed, which is 2400? If not, or if you have and are trying to use it at 3000, you need to get all of it running at its stock speed, 2400. You need to see if the CPU/memory controller, memory, and board together as a system can work with your memory at its stock speed. If it can't then something is not right and you'll need to diagnose it from there. If all your memory works fine at it stock 2400 speed, then you can move on from there to a higher memory speed.

FYI, all X99 HEDT processors like yours have their memory controller, which is part of the CPU itself, rated up to a speed of 2400. Speeds above 2400 are a memory over clock, and at best may need some work to achieve, and at worst may never be reached.

That means put all four DIMMs in the '1' slots only, A1, B1, C1, and D1. Be sure to use those slots, which are the closest ones to the CPU socket, in each of the four channels.

Then clear the UEFI/BIOS, which you can easily do using the CLR CMOS button on the board's IO panel. You must have the PSU off and unplugged from AC power when you use the CLR CMOS button. DO NOT skip clearing the UEFI/BIOS step, you MUST do this if you are serious about solving the problem.

When you clear the UEFI/BIOS, all the options will be reset to their default values. We want that for the memory, but if you have any other necessary settings, like RAID for the SATA mode (if you use it), you'll need to reset those again. That's normal after clearing the UEFI/BIOS.

It looks like from you pictures that you are using the EZ Mode of the UEFI/BIOS. You need to use the Advanced screens, so do that. There is more than one reason for this.

I want you to set an option only available in the Advanced UEFI screens, the DRAM Configuration screen, found in the OC Tweaker screen. In the DRAM Configuration screen, way down at the bottom (scroll down) find the MRC Fast Boot option. Set it to Disabled.

Below that option, find the Memory Test option, and set it to Enabled. Setting these two options will cause what is called "Memory Training" to occur, which helps when using large amounts of memory as you are.

You should also check the DRAM Voltage option, in the OC Tweaker, Voltage Configuration screen. That should be set to at least 1.2V, when the memory is at 2400 speed.

Question for you, have you installed Windows yet on this PC? Or are you simply using the UEFI/BIOS to look at the memory, etc?

As I alluded to at the beginning of my post, a review of this memory I found noted that when setting it to a speed of 3000 with the XMP2 profile, the XMP2 profile sets the BCLK to 125MHz, from the standard 100MHz. That change of the BCLK speed also affects the CPU speed, and causes a CPU over clock. For the standard 3.4GHz base speed of your CPU, that BCLK speed results in a CPU speed of 4.250GHz, and standard Turbo speed of 4.5GHz. That will happen when using one DIMM, or all four at the XMP2 speed of 3000.

http://www.hardwaresecrets.com/kingston-hyperx-predator-ddr4-3000-64-gib-memory-kit-review/4/

Which is why I'm wondering if you actually can run Windows at a CPU OC of that speed. Or was the review done with an earlier version of your memory, which no longer sets the BCLK to 125MHz. You need to verify if that happens or not. The BCLK frequency will be shown in the main OC Tweaker screen, and in the DRAM Configuration screen.

I've noticed when using the System Browser tool, it can take a while before all the memory is detected after the tool is started. You may even see "Detecting" when you hover the mouse pointer over the memory slots. Yes, a DIMM will appear in red when the mouse pointer is over that DIMM, that is not abnormal.

Went to a completely vanilla BIOS (fresh off the "plug out, CMOS clear button pressed") and set those two advanced memory settings suggested by parsec (MRC fast boot disabled, memory test enabled).

It's super unstable. Freezes up in windows with no stress on the machine.

I ran memtest86 and it froze up. Next boot, only 48GB. Did the complete CMOS reset, still only 48GB.

So I assume this indicates either the RAM of the D1 DIMM slot are bad. Still don't know how to get to the bottom of it.

Is there a better set of RAM I should buy? If I don't care about overclocking but want 64GB and a stable machine, what would you buy?