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> TSMC's 7nm process is stable, providing excellent yields and has plenty of available capacity

Yields in terms of getting lots of operational dies, sure, but one of the underlying problems here is chip quality. They have lots of chiplets but most of those chiplets are not fast enough to hit the clocks advertised for the 3900X.

In fact, even a lot of the chiplets sold as 3900X are not fast enough to hit the clocks advertised for 3900X, as well as elsewhere throughout their range. There are a lot of people finding their chips only boost to 50-200 MHz less than the advertised frequency of the chip.

Essentially, the boost algorithm now takes chip quality into account when determining how high it will boost. And most of the chips have silicon quality that is too poor to hit the advertised clocks, even on a single core, even under ideal cooling, etc etc.

Thus, AMD has the somewhat dubious honor of being the first company to make the silicon lottery apply not just to overclocking, but to their stock clocks as well. They really wasted no time before shifting to anti-consumer bullshit of their own; all they had to do was advertise the chips as being 200 MHz lower and everyone would have been happy, but they wanted to advertise clocks the chips couldn't hit.

And again, the underlying problem is chip quality - a lot of these chiplets can't boost to 4.3 or 4.4 GHz let alone 4.7. AMD simply can't yield enough 4.7 GHz chiplets to go around, even if the chiplets are nominally functional. The process may be "stable and providing excellent yields" but it's not stable and well yielding enough to meet AMD's expectations.

That's a major reason they're now introducing 3700 and 3900 non-X variations - that will allow them to reduce clocks and satisfy demand a bit better.




Not reaching advertised boost clocks seem to be related to newer AGESA releases from AMD to motherboard vendors, so I wouldn't blame it on chip quality just yet. These contain bugfixes (RdRand for example) and other changes, but has impacted boost clocks. People running AGESA 1.0.0.2 report reaching boost clocks easily (sustained in single-core tests), while I and others running later releases have issues.

New architecture, new chipset, bound to have some release issues. Intel is on its second or third refresh of their Skylake architecture from 2015, all ironed out.


> Intel is on its second or third refresh of their Skylake architecture from 2015, all ironed out.

More like the fourth, I think.


I've seen plenty of people having problems on older AGESA too. I've seen some people actually have higher performance on newer AGESA. It all depends on your particular sample and setup and how it fits into the boost criteria. Silicon quality still plays a massive role.

So to be clear, older AGESA isn't a magic bullet that is letting all chips "easily hit their rated boost clocks".

It could be cleaned up somewhat in future AGESA releases, and silicon quality will definitely go up over time.


>a lot of the chiplets sold as 3900X are not fast enough to hit the clocks advertised for 3900X

Do you have some sort of source for this claim?


der8auer has done extensive testing on multiple CPUs (he had 12 samples) and has discussed the topic.

https://youtu.be/WXbCdGENp5I?t=119

A lot of reviewers have noted similar things, but often are working with singular samples and didn't want to make too much of a stink without more data, but the problem is widespread. Out of all of der8auer's CPUs, only one hit its advertised boost clocks, and it was one of the lower-end CPUs with a less ambitious target to hit.

It may be a problem with early AGESA firmware, and silicon quality will definitely go up over time, but at least at this point in time AMD has certainly falsely advertised the clocks these CPUs are capable of achieving.


every forum pretty much. If you have been interested in getting one, and following along with the launch this is not a controversial statement. It's not 100% sure its the chips fault though, bios issues are still running rampant nearly 5 weeks later, and each new bios is changing performance significantly. It will take a while before everyone knows exactly where they stand.


Forums are not reputable sources unless it is insiders leaking info that can be verified through other means.


They might not be definitive sources, but they can definitely be the canary that triggers an investigation by somebody more authoritative.

As it stands, this mine has some dead canaries.


claim:

> ...but one of the underlying problems here is chip quality

supposed justification:

> ...every forum pretty much

That's hearsay not actual justification. And intel has a reputation for dirty play.


The justification was for the statement that chips aren't hitting their clocks. That is not a controversial statement.




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