Quote Originally Posted by drmrlordx View Post
3.8 GHz @ 1.3v is pretty good, especially with the stock cooler.

Lightman, can you do me a favor? Try booting with the stock DDR4-2133 settings, copying over all the timings/subtimings by hand, and then slowly run the RAM speed up to 3200 MHz. Set vDIMM as high as you're comfortable with, though I would recommend 1.4v vDIMM and anywhere from 1.1v to 1.175v SoC voltage. Let me know how far you can get with that thing.

I did this on my Taichi (actually used 1.42v vDIMM and 1.175 SoC voltage) and got up to DDR4-3466 . . . actually it was 14-14-14-28 + subtimings from DDR4-2133 default, but I digress.
I copied stock timings from 2133MHz, adjusted CL to 14-14-14-34-48 1T from XMP and ran it all the way up to 3466MHz. Unfortunately it wasn't stable, even with 1.42VDIMM and 1.1875 VSOC. I even adjusted trfc to what chew* suggested - 256/416/560 but still got errors. Windows was bench stable, but running memtest would detect errors within minutes.
Next I dialled down MEM clock to 3333MHz and all seems to be good with trfc of 132/192/312. I lowered SOC voltage to 1.1V and DDR to 1.375V (first dab in the dark, not tested lower yet). MemTest completed 1 pass without errors which is good enough quick check.

Now onto what this 2h long exercise brings:

(I've used mBench cmd app to get these measurements)

R7 1700 3815MHz DDR4 3466 ManualTiminigs CL14-14-14-34-48
Access latency 65.7 ns

Read datarate (INT) 19948 Mb/s
Write datarate (INT) 11418 Mb/s

Read datarate (MMX) 22879 Mb/s
Write datarate (MMX) 12656 Mb/s

Read datarate (SSE) 27684 Mb/s
Write datarate (SSE) 50105 Mb/s


R7 1700 3815MHz DDR4 3333 ManualTiminigs CL14-14-14-34-48
Access latency 67.8 ns

Read datarate (INT) 19665 Mb/s
Write datarate (INT) 11128 Mb/s

Read datarate (MMX) 22332 Mb/s
Write datarate (MMX) 12146 Mb/s

Read datarate (SSE) 27209 Mb/s
Write datarate (SSE) 48098 Mb/s


R7 1700 3815MHz DDR4 3200 ManualTiminigs CL14-14-14-34-48
Access latency 69.1 ns

Read datarate (INT) 19064 Mb/s
Write datarate (INT) 10811 Mb/s

Read datarate (MMX) 21971 Mb/s
Write datarate (MMX) 11741 Mb/s

Read datarate (SSE) 26594 Mb/s
Write datarate (SSE) 46253 Mb/s


R7 1700 3815MHz DDR4 3200 CL14 DOCP
Access latency 69.8 ns

Read datarate (INT) 18167 Mb/s
Write datarate (INT) 9054 Mb/s

Read datarate (MMX) 20685 Mb/s
Write datarate (MMX) 9935 Mb/s

Read datarate (SSE) 24859 Mb/s
Write datarate (SSE) 43533 Mb/s


R7 1700 3815MHz DDR4 2666 ManualTiminigs CL14-14-14-34-48
Access latency 76.8 ns

Read datarate (INT) 17091 Mb/s
Write datarate (INT) 9201 Mb/s

Read datarate (MMX) 19624 Mb/s
Write datarate (MMX) 10007 Mb/s

Read datarate (SSE) 23601 Mb/s
Write datarate (SSE) 38263 Mb/s