Discussion in 'AMD x86 CPUs and chipsets' started by aussie7, Sep 8, 2021.
I still have that kit in my collection!
I had a fairly major bios update and though I would revisit this. Thanks for the advice Aussie7 and OCMunkee. I loaded optimised defaults, turned on SPD and bumped the target VDIMM up from 1.35 to 1.49v (mclk fclk and uclk all at 1800 by default). All 32Gig installed.
It posted and did a run of the Heaven benchmark through twice. Min FPS up by 20%! Max FPS up 5%. Stoked to have the 4x8gig G-Skill DDR3600 CL16 running at the advertised speed.
I will do some further stress testing to confirm stability but I know what dodgy RAM looks like and there are no signs of it.
EDIT: It works well but given how long I keep PCs (at least a decade, this one already has a date for replacing my shed/workshop PC when windows 10 dies) I have wound it back to XMP less 400mhz so DDR 3200. A bit of a read around suggests that 1.47v which was the minimum stable) is a bit on the angry side.
here's my best suicide shot
Far out, that VDIMM is hot never mind the frequency.
Makes me comfortable I did not stuff anything being at and under 1.5v for an hour or two.
With some other Overclocking it would be interesting to see just what you can squeeze out of it for 3D graphics
Any particular reason for that tRFC/tRC/TFAW or is it just motherboard defaults? There should be some massive gains in latency and bandwidth just by setting those three timings lower. There are a few others there that could benefit as well.
Should be able to pull some values from this sheet: https://docs.google.com/spreadsheets/d/1cJmhO62WHPLNKGBtsJV3BjdL-dcfJJeyhdSAoJmuzJE/
I run my vdimm at 1.55v, PC on 24/7, while this is near the upper daily limit, it's still fine.
thanks for the link
mem settings were at motherboard defaults
Looking back to my last Intel rig (Asus Z270i, 7700K, GSkill Trident Z [Samsung B-Die] c17-3733), my daily settings were 5200+c12-4000.
My volts with those frequencies were 1.38v CPU+1.6v RAM with no discernible ill effects, over the 6 months or so I had the rig running as a daily with those voltages. I regularly bumped the RAM up to 2v for hours at a time when benching.
I would consider all DDR4 to be safe at 1.6v daily personally. RAM is easily RMA'd too (most RAM, if not all, comes with a lifetime warranty AFAIIK), so as long as you have spare RAM to keep your rig running while you wait for your new RAM/refund to come you'll be fine. I wouldn't describe the issue as "I had the voltage at 2v because Ratzz told me that it would cope no problem" during the RMA process if I were you though .
Generally memory will become unstable due to temps well before running any voltage that could harm it long term. There is of course risk to the CPU IMC, but on current Ryzen CPUs those voltages are still considered safe for the big lazy 14nm IO die, IIRC above 1.6v is where it starts to get a little sketchy.
more testing results
soc @ 1.4v and ram @ 1.7v (not daily, only for benching)
not sure how stable it is, but passed aida64 test
tm5 craps out almost straight away
more testing, got 1hr pass on occt at 4800 2400
just needed to drop the curve to -5 and set the VDDP volts to 1.15v
needs more adjusting, but its a start
ok, 4800mhz and 2400fclk is no good, too high volts and unstable
so back to 4733mhz @ 1.5v and 2367fclk @ soc 1.25v rock solid
latest zen timings screen shots, both pass TM5 short test, with many thanks to glnn_23
ok went old school and used Memtest86 to test my ram settings
passed with the following settings
just in case anyone is still here, this is a rough test of mem overclock
ram timings were 21-22-58-2T and everything else on auto
still testing so may get higher, but I doubt it
some more testing, still working on stability though
just got a quick CB15 cpu run and a quick Aida test