Extremely slow ram speeds

OM222O · 2025-03-01T12:22:41+0000

Hi, I'm running a 9800X3D on ROG X870E Hero and 96 GB DDR5 8000 ram (2 kits of https://www.gskill.com/product/165/390/1725939074/F5-8000J4048G24GX2-TZ5NR). The QVL does specify my motherboard but after I turned on expo, I couldn't boot anymore and had to reset CMOS.

This set the memory speed to ddr5 3600. Now I can't get any setting other than "auto" for everything to boot which is ddr5 3600. The weirder issues is setting the speed to 3600 also causes instant crashing! I tried both the "extreme tweaker" tab and "advanced -> amd over clocking" and setting FCLK to 2000, UCLK = MemCLK and enabling expo but setting the target speed to 3600. What's different between auto everything and manual 3600? How can I determine if the motherboard, CPU or RAM is the bad component? is there a general guide on AMD RAM overclocking that goes into more detail than "UCLK can run upto 3.2/3.3 if you're lucky at 1.3V and MEMCLK > 6000 requires running in 2:1 mode"? I think something is seriously wrong because even with 1:1 mode I should be able to easily booth with 4000MTPS ram but even 3600 fails when set manually. What are my options for troubleshooting this?

For reference this is the only speed and timings I can get into windows (10 with all the latest updates) with:

opethdisciple · 2025-03-01T13:14:35+0000

Could be the CPU can't handle 8000MHz.

If the ram is new enough can you send it back and get a 6000MHz kit?

Have you flashed the latest bios for the board?

Might be worth sending a message to Asus support to see what they say.

But I see two potential issues the amount of ram is high plus the speed.

Also you are running 4 sticks?

This might be an issue too.

Tetras · 2025-03-01T13:21:43+0000

OM222O said:
Hi, I'm running a 9800X3D on ROG X870E Hero and 96 GB DDR5 8000 ram (2 kits of https://www.gskill.com/product/165/390/1725939074/F5-8000J4048G24GX2-TZ5NR).

By 2 kits, are you saying that the PC is running 4 sticks?

4x48GB is not easy to run, AMD officially only guarantee 3600 for 4 dual rank sticks (48GB are dual rank) which is probably why the board boots at this crappy speed.

Enabling EXPO might cause the board to configure itself in a way that it can't support, even with a manual frequency of just 3600.

You could have a look on Level1Techs forums, he has made videos on the topic:

Firegod · 2025-03-01T13:25:43+0000

Everything about this seems wrong to me. 8000Mhz, 4 DIMMS, on an AMD CPU. I'd drop down to 64GB if you can get away with not having 96Gb, and use 2 DIMMS at 6000Mhz and CAS 28.

G.Skill Ripjaws M5 NEO RGB EXPO 64GB (2x32GB) DDR5 PC5-48000C28 6000MHz Dual Channel Kit - White

Order G.Skill Ripjaws M5 NEO RGB EXPO 64GB (2x32GB) DDR5 PC5-48000C28 6000MHz Dual Channel Kit - White now online and benefit from fast delivery.

www.overclockers.co.uk

OM222O · 2025-03-01T13:27:41+0000

opethdisciple said:
Could be the CPU can't handle 8000MHz.

If the ram is new enough can you send it back and get a 6000MHz kit?

Have you flashed the latest bios for the board?

Might be worth sending a message to Asus support to see what they say.

But I see two potential issues the amount of ram is high plus the speed.

Also you are running 4 sticks?

This might be an issue too.

yes, running the lates bios (1104) and like I said, even dropping the speed to dizmally slow 3600 doesn't seem to work.
Running 4x24GB sticks (2 kits of the linked trident z ram). Even if I can't run at 8000, I should be able to do 5600 JEDEC spec on the worst CPU/MOBO/RAM combo but something is preventing that.

Tetras said:
By 2 kits, are you saying that the PC is running 4 sticks?

4x48GB is not easy to run, AMD officially only guarantee 3600 for 4 dual rank sticks (48GB are dual rank) which is probably why the board boots at this crappy speed.

Enabling EXPO might cause the board to configure itself in a way that it can't support, even with a manual frequency of just 3600.

You could have a look on Level1Techs forums, he has made videos on the topic:

Not running 48GB but 4x24GB sticks, I'll check the video, thanks.

Firegod said:
Everything about this seems wrong to me. 8000Mhz, 4 DIMMS, on an AMD CPU. I'd drop down to 64GB if you can get away with not having 96Gb, and use 2 DIMMS at 6000Mhz and CAS 28.

G.Skill Ripjaws M5 NEO RGB EXPO 64GB (2x32GB) DDR5 PC5-48000C28 6000MHz Dual Channel Kit - White

Order G.Skill Ripjaws M5 NEO RGB EXPO 64GB (2x32GB) DDR5 PC5-48000C28 6000MHz Dual Channel Kit - White now online and benefit from fast delivery.

www.overclockers.co.uk

I can't return the sticks as I bought them in Nov but didn't have time to build. Can't throw away 500 bucks and buy new ram either.

opethdisciple · 2025-03-01T13:28:36+0000

OM222O said:
yes, running the lates bios (1104) and like I said, even dropping the speed to dizmally slow 3600 doesn't seem to work.
Running 4x24GB sticks (2 kits of the linked trident z ram). Even if I can't run at 8000, I should be able to do 5600 JEDEC spec on the worst CPU/MOBO/RAM combo but something is preventing that.

I think the consensus is that 4 sticks is the issue.

opethdisciple · 2025-03-01T13:29:21+0000

Firegod said:
Everything about this seems wrong to me. 8000Mhz, 4 DIMMS, on an AMD CPU. I'd drop down to 64GB if you can get away with not having 96Gb, and use 2 DIMMS at 6000Mhz and CAS 28.

G.Skill Ripjaws M5 NEO RGB EXPO 64GB (2x32GB) DDR5 PC5-48000C28 6000MHz Dual Channel Kit - White

Order G.Skill Ripjaws M5 NEO RGB EXPO 64GB (2x32GB) DDR5 PC5-48000C28 6000MHz Dual Channel Kit - White now online and benefit from fast delivery.

www.overclockers.co.uk

Cas 30 will do just fine too.

opethdisciple · 2025-03-01T13:30:49+0000

As a test take two sticks out and see what happens.

OM222O · 2025-03-01T13:41:36+0000

I tried manually typing all the timing values from the EXPO profile and some of them (tRAS 128, tWR 12) error out with "invalid input range". Setting tRAS to 126 and tWR to 54 I can now boot with 4000! Is this a bug in the BIOS / EXPO profile? why does it use invalid values? who should I report this to? Gonna try higher speeds and will update on success / fail.

Tetras · 2025-03-01T13:47:22+0000

OM222O said:
Not running 48GB but 4x24GB sticks, I'll check the video, thanks.

I'm not sure there's anything useful in the video, I was suggesting you check his forums for tips. Officially AMD still only rate the memory controller for 3600 with 4 single rank sticks, but realistically you should do better than that.

OM222O · 2025-03-01T13:53:33+0000

Indeed changing tRAS and tWR seems to have somewhat fixed the issue, I can now run at 5600 without crashing. Gonna try pushing further. Still, I'm not sure whether to contact ASUS or G.SKILL as they collaborate on the QVL and supported profiles but clearly the values on the profile are out of range / broken.

opethdisciple · 2025-03-01T14:27:56+0000

OM222O said:
Indeed changing tRAS and tWR seems to have somewhat fixed the issue, I can now run at 5600 without crashing. Gonna try pushing further. Still, I'm not sure whether to contact ASUS or G.SKILL as they collaborate on the QVL and supported profiles but clearly the values on the profile are out of range / broken.

But the sticks come in pairs. Those profiles are for two sticks not four.

Tetras · 2025-03-01T14:32:00+0000

OM222O said:
Still, I'm not sure whether to contact ASUS or G.SKILL as they collaborate on the QVL and supported profiles but clearly the values on the profile are out of range / broken.

I can't find those particular sticks on the QVL for your motherboard and from what I can see, similar sticks are only tested for 1 or 2 slots, not for 4.

I don't know if what you encountered with the timings is due to the input values specifically, or due to having EXPO being enabled causing the board to be more aggressive elsewhere. EXPO doesn't only configure the memory and it will almost certainly be optimised for only running 2 sticks.