Okay what's going on here with Asus X470 Pro + TridentZ at rated speed

[xorbe]

Worked on my brother's 2700X + Asus X470 Pro (latest bios). The memory won't run at the actual rated speed of 3200, but it will run one under or one OVER. G.Skill TridentZ 14-14-14-34 (Samsung B die), in ANY of the following configurations same results as below: 2x8, 4x8, 2x16.

2xxx 14-14-14-34 great
30xx 14-14-14-34 great
3133 14-14-14-34 great

3200 14-14-14-34 won't even post
3200 16-22-22-53 prime95 blend errors
...
but
...
3266 14-14-14-34 great!
3333 14-14-14-34 almost but will eventual throw a p95 blend error
3400 14-14-14-34 crash after a minute

We manually forced 3266 timings with 3200, and it still exploded. Clearly this is about hidden timings, and not the bus speed. We went with 3133. What's going on with 3200?? My wag is some Asus auto-optimization fuckery or something, but I don't know.

 

[mda]

Probably some quirky memory ratio problems that the IMC just doesn't do well at... just like how people discovered that those CPUs can do 3200 and 2933 with good memory but won't do 3000.

 

[pitingres]

I see something similar with an Asrock X470 Taichi; I can run 2x16 of that same TridentZ at 3133 all week long, but 3200 will hang after a day or two, even with increased voltage. Every few months I get energized to fool with it, and invariably end up back at 3133; not the the difference is important, it just ticks me off that it won't run at rated speeds. Maybe I should try one step over 3200 the next time I mess with it.

 

[kirbyrj]

That's strange only because I know that on the Crosshair VII and the Strix X470-F I haven't had issues running straight DDR4 3200 speeds (both with Samsung B-die and Hynix M-die). But I have had similar issues with ASRock boards. Just sounds like the Asus board doesn't like that 1:16 RAM divider.

I will also say that Ryzen IMC's are not all created equal. You just never know what you're going to get. This 1700X I'm on shouldn't really be running M-die at 3200mhz, but here I am... But I've had 2600's that wouldn't run Samsung B-die at rated speeds.

 

[MMitch]

That's strange only because I know that on the Crosshair VII and the Strix X470-F I haven't had issues running straight DDR4 3200 speeds (both with Samsung B-die and Hynix M-die). But I have had similar issues with ASRock boards. Just sounds like the Asus board doesn't like that 1:16 RAM divider.

I will also say that Ryzen IMC's are not all created equal. You just never know what you're going to get. This 1700X I'm on shouldn't really be running M-die at 3200mhz, but here I am... But I've had 2600's that wouldn't run Samsung B-die at rated speeds.

Same here, CH7 with 4x8 GB FlareX 3200 no issue.

OP, you mention you tried 2x8 4x8 and 2x16, how many memory kits do you have on hand ? When I bought my new system, I read Samsung B Die were the best but to aim for Single sided, hence why I went with 4x8 FlareX.
Make sure you choose a kit AMD tested and you may want to add some voltage.

If "3266 14-14-14-34" is great, why not use that ?

 

[xorbe]

Same here, CH7 with 4x8 GB FlareX 3200 no issue.

OP, you mention you tried 2x8 4x8 and 2x16, how many memory kits do you have on hand ? When I bought my new system, I read Samsung B Die were the best but to aim for Single sided, hence why I went with 4x8 FlareX.
Make sure you choose a kit AMD tested and you may want to add some voltage.

If "3266 14-14-14-34" is great, why not use that ?

At the time we had 4x8 and 4x16 on hand of the TridentZ for testing. The problem PC was my brother's and I didn't want to run over spec and hear about 3266 problems later (since 3333 didn't work), so I chose 3133 as the safer choice. If you look at the timings and results in the first post, you'll see that it couldn't really be voltage related. He said the PC is still working great, so that's good.

 

[Thatguybil]

Back in the day we would chalk this up to FSB and memory divisor issues. Multiples of whole numbers were always easier to hit.