Hello, I’ve been spending some time lately taking another crack at tuning the DDR5 in my system and I’m hoping to get a little help/direction on where to go from here.
System –
13900KS – a very run of mill example in terms of silicon fitness. Running 5.8 8P, 4.5 E, 5.0 Ring @ 1.425v
MSI Z790 Tomahawk Wifi DDR5 (sad 4x DIMM noises)
G-skill 32GB (16×2) Trident Z5 RGB 6800 CL 34-45-45-108 – confirmed A-die
4090 vertically mounted – absolutely dumps heat into the case
Current settings –
7400 CL34, 43 for tCL/tRCD/tRCDW/tRP, 28 tRAS, 500 tRFC2, 400 tRFCPB, tREFI 32000
CPU SA 1.2v, CPU VDDQ 1.4v, CPU VDD2 1.42v, DRAM/VDDQ 1.44v, SA PLL 0.990v, MC PLL 0.990v.
[Screenshot of Timings + HWinfo64](https://postimg.cc/p9swWJZK)
With the above voltages I’ve sketched out these settings roughly. I’m relatively new to memory overclocking but not overclocking in general, so go easy on me. In terms of what I’ve chosen, I would try and get the settings to pass roughly an hour of OCCT memory test SSE and AVX2 each before moving onto the next timing, along with running Furmark in the background to simulate realistic ambient case heat. The above is where I landed being reasonably satisfied with achieving a decent frequency increase and a mild tightening of most(?) of the primary timings and a few secondaries.
Some things I’ve noted –
\- My IMC likes 1.2v a lot more than 1.3v or even 1.25v. 1.3v is what is selected by the XMP kit as default, and both 1.25v and 1.3v start erroring with the above settings within a few minutes.
\- My DIMMs will hit the high 60s temp wise given the stability testing I’ve been doing. In real world use, like a GPU load in the 400w range and CPU+streaming load in the 180-220w range, they are usually in the 61-63C range. I’ve already ordered a fan mount and a NF-A12x25 that I intend to point directly at them.
\- I couldn’t tighten CL any lower than 34 without going down to the 7000, where I believe I had CL32 stable for an hour of each test.
\- I couldn’t get tREFI any higher than 32k or so, via it being so sensitive to heat. 65535 would error within a few minutes.
With being relatively satisfied with the above timings, I set out to try to pass some longer tests. I passed 8h of OCCT AVX2 + Furmark with zero errors, but repeating the same test with SSE errored at roughly the three hour mark. This makes me think perhaps my CPU IMC is the source of the error? I recall reading that SSE is harder on the IMC and AVX2 harder on the DIMMs. I’ve also passed roughly 2 hours of Y-Cruncher VST+VT3 with plans to try and pass a longer stint of that as well.
I’m looking for suggestions for trying to stabilize my current settings, or perhaps other timings I should try and tune? I’m pretty happy with what I currently have, but if there was a timing that had a large performance impact I’d perhaps try.