4x48 GiB @ 6000 MT/s on AM5
Impressively this was done in gear 1
Processor CA drive strength: 30 ohm
DRAM ODT impedance RTT_NOM_WR: RZQ/4 (60)
DRAM ODT impedance RTT_NOM_RD: RZQ/4 (60)
DRAM ODT impedance RTT_WR: RZQ/2 (120)
Processor ODT impedance: 48 ohm
Processor DQ drive strength: 34.3 ohm
DRAM DQ drive strength: 34 ohm
This was done thanks to
reddit guide by
andymetzen
Greetings from the country of Taiwan🇹🇼! It looks like we can finally run 128GB of DDR5 at the sweet spot of 6000MT/s on the AM5 platform!
I managed to find budget-friendly A-Die DDR5 sticks for $100 per 32GB, and paired them with a cheap ASRock 8-layer board priced at $250. After updating the BIOS to the latest AGESA 1.0.0.7b, I applied
u/buildzoid's timings. I'm thrilled to report that my 128GB(4x32GB) setup has been 24/7 stable at DDR5-6000 30-38-38-28 UCLK=MEMCLK! I ran Memtest86 for 4 passes, LinpackXtreme for 33 runs, and AIDA64 for 4 hours, and I didn't get any errors.
128GB(4x32GB) DDR5-6000 30-38-38-28 UCLK=MEMCLK
While attempting 128GB(4x32GB) at DDR5-6400 with timings set at 32-39-39-28 and UCLK=MEMCLK, the system successfully booted into Windows. However, it didn't pass stability tests. If you're able to get 128GB stable at 6400MT/s with UCLK=MEMCLK, please share your settings!
Specs:
- Processor: AMD Ryzen 9 7950X, air cooled
- Motherboard: ASRock X670E PRO RS (BIOS: 1.28.AS01) (USD$250)
- Memory: 4x 32GB ATADA XPG LANCER RGB DDR5 AX5U6400C3232G-DCLARWH (Hynix A-Die) (USD$400)
Impossibly high aida64 number for write-bandwidth here:
Simply applying EXPO/XMP did not boot for me. The key was manually setting the following nine memory bus termination values:
- ProcOdt = 48Ω
- ProcCaDs = 30Ω
- ProcDqDs = 34.3Ω
- DramDqDs = 34Ω
- RttNomWr = RZQ/4 (60)
- RttNomRd = RZQ/4 (60)
- RttWt = RZQ/2 (120)
- RttPark = RZQ/5 (48)
- RttParkDqs = RZQ/5 (48)
Here is what I did:
- Start at 5400 MT/s and make it stable.
- Increase the memory speed by 200 MT/s and make it stable.
- Repeat step 2 until you reach the limit of your system. (5600 -> 5800 -> 6000 -> 6200 -> 6400)
Expect memory training times of 8 to 9 minutes every time you make changes in the UEFI. Sometimes it might even take up to 20 minutes before entering the UEFI.
With "Memory Context Restore" Enabled and "Power Down Enable" Enabled, you should be able to access the UEFI within 10 seconds if nothing was changed in the UEFI. (In 1.0.0.7b, if you do not enable "Power Down Enable" with "Memory Context Restore," the system will fail to POST on the second boot.)
For those who desire every single detail, here is the complete list of my UEFI changes (PBO per core tuning is not included since those are chip-specific):
UEFI changes (PBO per core tuning is not included since those are chip-specific)
