1.Extract SiInitPreMem，GUID:A8499E65-A6F6-48B0-96DB-45C266030D83.
2.Search "C786....000000....00"，".." is any HEX value.
3.The first place of “....” is not important，the second place of "...." will show "8000" or "0001" , "8000" means maximum 64GB , and "0001" means maximum 128GB.
4.Replace "800000" with "000100" .
5.Make sure the Chipset->System Agent (SA) Configuration->Above 4GB MMIO BIOS assignment is set to Disabled. Some motherboard do not need this adjustment.
6.Set HAP bit of Intel ME in Flash Descriptor.
7.After all, you can use 128GB on it.

I can see the same hex pattern in Z170/Z270 BIOS , but I don't know whether SKL/KBL can support 128GB or not.
Most MSI Z370 motherboard already have "000100" in their latest BIOS , so they should be ready for 128GB RAM.
Some Z170/Z270/Z370 with patched BIOS and 128G RAM will face PCIE RESOURCES ERROR every boot.But in system ,all 128GB can be accessed.

Update: Test with ASUS/Gigabyte Z370 , G4400/i3-8100/i5-9400 , must set HAP bit of ME in Flash Descriptor , or the 128G won't work.
G4400 + ASUS Z370-P Ⅱ + 32GB *4 works perfectly.
ASUS Z170-A works.


Edit by Fernando: Thread title customized

awesome post, thank you dsanke. I have been searching everywhere to see any indication that Z370 might work with 128GB (which it absolutely should do!) ... and you have done exactly that. I use an Asrock Z370 though, so not sure if the BIOS is set up for it. Hopefully it is before paying so much for the (excellent I'm sure) Corsair 32GB RAM units.

@dsanke

Zitat von dsanke im Beitrag #1

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1.Extract SiInitPreMem，GUID:A8499E65-A6F6-48B0-96DB-45C266030D83.
2.Search "C786....000000....00"，".." is any HEX value.
3.The first place of “....” is not important，the second place of "...." will show "8000" or "0001" , "8000" means maximum 64GB , and "0001" means maximus 128GB.
4.Replace "8000" with "0001" , and you can use 128GB on it.

I can see the same hex pattern in Z170/Z270 BIOS , but I don't know whether SKL/KBL can support 128GB or not.
Most MSI Z370 motherboard already have "0001" in their latest BIOS , so they should be ready for 128GB RAM.

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@niceblue

Zitat von niceblue im Beitrag #2

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awesome post, thank you dsanke. I have been searching everywhere to see any indication that Z370 might work with 128GB (which it absolutely should do!) ... and you have done exactly that. I use an Asrock Z370 though, so not sure if the BIOS is set up for it. Hopefully it is before paying so much for the (excellent I'm sure) Corsair 32GB RAM units.

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Zitat von XPLives im Beitrag #3

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What program are you using to extract?

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@dsanke
Looking into the BIOS isn't my expertise.

I tried using UEFITool v0.25.1 and couldn't do much.

Here are the links to the actual BIOS download files from the AsRock site.

https://www.asrock.com/mb/Intel/Fatal1ty...ming%20i7/#BIOS

You can take a look at both versions 7.10 and 7.50 and let me know if you see any result if it supports 128GB or not. I only have 7.10 installed.

you said exactly what I wanted to do. I was going to buy 2x32gb corsair just to test with 96gb, but sounds like it doesn't seem to work as you expect. Thank you for mentioning this.

I am considering then buying the full 4x32gb, but need a bit of time to gather the money to do that. Hopefully within the next two months ... I will let you know here if I do that and what happens!

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btw, it might not work as you expect because you mentioned trying to use 3x32gb? This doesn't work well because it will no longer be dual channel. Perhaps if you try 2x32gb in one channel and 2x16gb in the other channel it would then work for the full 96gb?

@niceblue

Zitat von niceblue im Beitrag #8

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btw, it might not work as you expect because you mentioned trying to use 3x32gb? This doesn't work well because it will no longer be dual channel. Perhaps if you try 2x32gb in one channel and 2x16gb in the other channel it would then work for the full 96gb?

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Zitat von XPLives im Beitrag #6

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Looking into the BIOS isn't my expertise.

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@dsanke

I might do a 32GB pop in test to see if it detects it at all without modding.

I downloaded your P7.50 BIOS mod,

But if you can repeat the same for the P7.10 that is the one that I used for XP->Windows 10 Compatibility Testing.

Also what software can burn this ROM directly to the BIOS chip while still in the MB BIOS socket while in DOS?

Now I'm curious since you added Coffee Lake microcodes and I do have a i5-8400 but from what Lost_N_Bios has told me it still requires a CPU Pin modding.

Any ideas if this can be avoided if the CPU Core Voltage and Clock speeds are lowered for 800 MHz operation to reduce wattage for testing?

I'm not quite read to sacrifice that chip. But does going the other way and adding older gen SkyLake and Kaby Lake microcodes allow these CPUs to work on the newer Coffee Lake Z370 socket without CPU pin modding?

So were both the P7.10 and P7.50 BIOS versions missing 128GB Memory Capacity support?

Zitat von XPLives im Beitrag #11

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So were both the P7.10 and P7.50 BIOS versions missing 128GB Memory Capacity support?

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Zitat von XPLives im Beitrag #11

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Also what software can burn this ROM directly to the BIOS chip while still in the MB BIOS socket while in DOS?

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Zitat von XPLives im Beitrag #11

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Lost_N_Bios has told me it still requires a CPU Pin modding.

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Zitat von XPLives im Beitrag #11

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Any ideas if this can be avoided if the CPU Core Voltage and Clock speeds are lowered for 800 MHz operation to reduce wattage for testing?

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I did some more tests.

I got the 96.0GB recognized in Vista Ultimate 64-Bit SP2 on my older AMD AM4 MB using a Bristol Ridge Dual Core.

Since this CPU is extremely old compared to the i5-8400 and the BIOS is older than the Intel Z370 one by half a year this leads me to believe the CPU does not affect the > 64.00 GB memory limit.

It is a BIOS related issue most likely since both MBs can see 96.0GB installed in the BIOS and in the System Properties, General Tab but on the Intel Z370 it wouldn't see above the 64.0GB for usable memory for some strange reason.

Some further testing showed Windows 7 32-Bit could not break the 64.0GB memory barrier on the AMD AM4 despite breaking it on the 64-Bit OS.

So the 32-Bit PAE might have a true 64.0GB limit after all regardless of AMD or Intel and is a forced MS OS limitation.

Anything more than 64.0GB of memory to be accessible will require a compliant BIOS and a 64-Bit OS maybe as early as XP IA64 might have been able to hit this limit or at least above 64.0GB but unknown if it was ever attempted on such legacy hardware at the time and MS states 128GB as not supported leaving XP Pro 64-Bit probably the earliest to break the 64.00GB limit without issue.
https://docs.microsoft.com/en-us/windows...mits-windows-xp

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@niceblue

Zitat

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btw, it might not work as you expect because you mentioned trying to use 3x32gb? This doesn't work well because it will no longer be dual channel. Perhaps if you try 2x32gb in one channel and 2x16gb in the other channel it would then work for the full 96gb?

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After further testing if you're willing to invest in 2 x 32GB to pair with your 2 x16GB to reach 96GB, I suggest trying these tips.

Set the memory clock speeds for all to 1600MHz first and saving the BIOS settings before installing any new memory or removing.

After it is powered off install the memory in this pattern.

Starting with the memory slot closest to the CPU:
16GB DDR4
32GB DDR4
16GB DDR4
32GB DDR4

After powering on it should automatically try and detect the total 96.0GB and be sure to use a 64-Bit OS such as XP Pro 64-Bit, Vista Ultimate 64-Bit, or Windows 7 Ultimate 64-Bit which should fully detect the memory in the OS and in the Task Manager. Later you can adjust up to 2400 MHz Memory Clock Speed and up incrementally from there for the lowest compatible stable setting.

If this works let me know when you take the second set plunge to hit the 128GB max.

I think using all the same Brand / Model / Clock Speed all matching it will work smoothly without issue.

If not upgrade the BIOS version increment one step at a time to see which BIOS version finally patches the 64.0GB+ usable memory issue.

Also which Brand MB / Model / BIOS version and CPU model are you using?

@dsanke do you know what is the value of 32 GB RAM limit string? I am sitting on Asrock Z270M ITX Gaming with 2 slots - there is 32 GB limit and I could try to modify it to 64 GB limit for future use as 32 GB dimms have just entered the market.

Zitat von pacuro im Beitrag #13

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@dsanke do you know what is the value of 32 GB RAM limit string? I am sitting on Asrock Z270M ITX Gaming with 2 slots - there is 32 GB limit and I could try to modify it to 64 GB limit for future use as 32 GB dimms have just entered the market.

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I haven't try 2x32 yet. It is just info on manufacturer website (- Max. capacity of system memory: 32GB). Even though I can't find 64GB limit string from your point 2 in bios image.