We built two PC's here are the specs.
AMD Ryzen 1700x
Cooler master water coolers.
ASUS Prime X370-Pro AM4
G.SKILL Ripjaws V Series Model F4-3200C14D-16GVR
Both have the same exact bios.
PRIME X370-PRO BIOS 0604
Update AGESA to 126.96.36.199a
Leaving the Bios at default settings and only changing the XMP profile to 3200 and correct timings. Lowering the Ram to 2933 on one PC works while the other PC will not go above 2400 or it will not boot... Like I said same exact setting, one pc is able to run 2933 and one is stuck at 2400...
The ram, mobo, bios are all the same. This makes no sense to me... The Ram is Samsung B-Die
AMD released the AGESA 188.8.131.52 update to board partners last week which should solve those problems. Ryzen works better with Samsung B currently, but it's not guaranteed at this point.
AGESA 184.108.40.206 will uncover 20 more memory registers. AMD said that Ryzen works BETTER with Samsung B die memory, but they did not say it works flawlessly.
Your question was "Why won't machine A run at full speed when machine B can". I told you why, until AGESA 220.127.116.11 is applied memory speeds are not guaranteed.
lol omg... the pc's are exactly the same... exactly the same parts, exactly the same bios.... Waiting for someone else to reply now since you clearly are not understanding.
Google and learn about "binning". Just because you have two identical CPU's or two identical sticks of RAM that doesn't mean they will perform the same.
Binning is not the issue, before the latest Bios I was able to get atleast 2666 out of the ram. now it wont go past 2400. The other PC stayed at 2933 thru bios updates....
Binning chips according to their tolerance. If they cannot perform stable at their rated speeds they sell them as the lower model... Even if that were the case with my RAM, it still should be capable of atleast 2933 like the other PC. This isnt the problem...
They take the lesser capable chips and step them down a bit and sell them as a model where they will run stock speed @ x volts 100% stable... rather then risk selling a part that might not hack it at a higher speed @ x volts and have it fail and get RMA'd
Think GTX 465 vs 470... some reports indicated that some early 465 included the same configured PCB as the 470 (not missing any components) and just a lesser bios... once unlocked by some it was basically like buying a 470 for less... This isnt exactly what binning does... but it stands to reason that NVIDIA sold 470 chips that were binned lower... as 465 chips for mfgs.