G.SKILL F5-7200J3445G16G Impossible to overclock

[Vaporator]

Hi all,
i really need your help since i am very disappointed on my Ram blocks.
I have a brand new computer put together with great parts and I am experiencing RAM errors when trying to overclock them the slightest, even XMP profil1 won't make the computer boot randomly and crash if I load a game or run testmem5 where it also comes with many errors. I also tried to update the timings and voltage manually, but it was not possible, it won't boot if I do it manually .
I updated the bios to the latest version also if that would be the error but with no luck. i also checked if they are compatible with the motherboard and they are listed as compatible at gigabyte.

Here is my system setup and its powered by a Corsair RM1000x
https://valid.x86.fr/xrsz81

[GSKILL TECH]

That is the case when you have full slots. Read more at the bottom of the Memory list:

https://www.gigabyte.com/Motherboard...support-memsup

DDR5 4800 MHz speed drops down to 4000 MHz when 4 DIMMs are populated (1Rx8/ x16 modules).
DDR5 4800 MHz speed drops down to 3600 MHz when 4 DIMMs are populated (2Rx8/ x16 modules).

Did you test each memory kit separately to see if they have the same results? They should be in slots A2 B2 , and another kit in A1 B1 if you wish to attempt full slots.

[Vaporator]

Aha, but why does the XMP then recommend a setting there isn't working.
Anyways, I am guessing my RAM Blocks are 2Rx8 and then my maximum mhz speed for these RAM blocks would be 3600 mhz?

I didn't test them as single kits yet, but I will do in the weekend.

[emissary42]

Your modules should be single rank, so it is two 1Rx8 modules per channel.

The XMP is part of the memory SPD. It is developed and tested for a single kit usage with the motherboards from the G.SKILL QVL. The motherboard applies those settings once the function in the UEFI is enabled. It does not know if it can actually support these specifications.

If you combine multiple kits, frequency-wise you will often be limited by the platform / motherboard itself, since most dual channel motherboards only support the highest frequencies with two modules in their primary DIMM slots. You can however attempt to still use the XMP with a reduced memory ratio*. Go down from DDR5-7200 step by step, until the system does successfully POST and is fully stable.

*Some motherboards automatically generate additional variants of the XMP, that can be used as an alternative or fallback.

[GSKILL TECH]

XMP is for a single memory kit of the memory modules it came matched and tested with. That XMP capability goes out the window once you add anything else not intended to work with it. For that reason to confirm there is no issue with each memory kit, it is recommended to test them separately to see if both have the same results.

Maximum needs to be tested, but surely a lower frequency should be expected than with 2 modules.

[Vaporator]

After testing the kits alone i can run XMP1 profile stable at 7200, but with 2 kits I can only make it run stable at 4400. Is this considered good, in my opinion, even though I am not a specialist in ram its a bit in the low end no?

[emissary42]

Did you test the XMP with all ratios between 7200 and 4400?

Leave the XMP enabled in the UEFI and reduce the DRAM ratio step by step until the system successfully starts and is stable. I would be very surprised, if you actually had to go all the way down to 4400, with a somewhat decent Z790 motherboard.