This isn't exactly overclocking. Rephrased in terms of CPUs: it's as though motherboards always clocked the CPU to 2.1GHz, irrespective of what is indicated on the CPU box. This happens with RAM because there used to be no way for the RAM to advertise its speed and timings to the motherboard. Intel corrected this with XMP on their platform (I'm not sure what the AMD equivalent is called).
If you clock your memory to its advertised speed and timings (i.e. enable the XMP profile) you ~~won't~~ [edit] shouldn't have any problems after booting. What may happen is that your system fails to POST, in which case you need a better motherboard.
Using the correct memory profile is extremely important. Reviewers found that the performance of Ryzen is strongly correlated to the memory clock - something to do with Infinity Fabric. This means that DDR4-4000 is, in theory, absolutely required if you want the most out of Ryzen - making this patch a big deal for Ryzen users.
My understanding (please, someone tell me if I'm off base!) is that the infinity fabric is kind of like Intel's QuickPath Interconnect and the "uncore" in one.
In Intel systems it was* required to have the uncore clock be twice the memory clock-rate. The "uncore" clock rate controlled the clock for caches, the memory controllers, possibly other IO components, and the like.
It makes sense that certain benchmarks would be insensitive to increases in memory frequency if those same components were locked at ~2.1GHz in Ryzen's initial release.
On a related note: does AMD publish block diagrams for their infinity fabric or is there any firm information about how many PCIe 3 lanes will be available on the Threadripper platform?
> On a related note: does AMD publish block diagrams for their infinity fabric or is there any firm information about how many PCIe 3 lanes will be available on the Threadripper platform?
I'm interested in a block diagram or documentation as well, if anyone knows of any.
PcPer did some tests which show the inter-core latency and some other experimental data.
> My understanding (please, someone tell me if I'm off base!) is that the infinity fabric is kind of like Intel's QuickPath Interconnect and the "uncore" in one.
Yeah that sounds about right. The only thing I will add is that I've heard (can't source) inter-die communication on Threadripper/EPYC multi-chip-modules apparently happens by a different mechanism than intra-die/inter-CCX communication.
As such, my suspicion is that Threadripper and EPYC will basically behave like a multi-socket system.
As for lanes: I think it's official at this point that Threadripper has 44 lanes like Skylake-E does, and EPYC has 128 PCIe lanes. Possibly plus additional lanes from the PCH?
If you clock your memory to its advertised speed and timings (i.e. enable the XMP profile) you ~~won't~~ [edit] shouldn't have any problems after booting. What may happen is that your system fails to POST, in which case you need a better motherboard.
Using the correct memory profile is extremely important. Reviewers found that the performance of Ryzen is strongly correlated to the memory clock - something to do with Infinity Fabric. This means that DDR4-4000 is, in theory, absolutely required if you want the most out of Ryzen - making this patch a big deal for Ryzen users.