Question Zen 6 Speculation Thread

[adroc_thurston]

the fact that ram speed and latency still affects gaming performance is a big one

View attachment 128731
Look at this graph from chips and cheese and I think it can become more clear. There is literally 4x more latency from DRAM compared to L3. If AMD can move that blue line over another segment, cache hit-rates will still continue to go up. Maybe games will finally hit diminishing returns (I doubt it), but overall efficiency would still be greater for any task that would have gone to memory.

We're so lucky that clam also does per-workload cache hitrate breakdowns that for some reason you forgot to poast.
Wonder why.

 

[dr1337]

This chart can't be used as proof that games will see an uplift. It all depends on the size of the working set of the particular game. Depending on the exact figure, additional hitrate may not actually compensate for additional latency of a larger L3.

nah, X3D CPUs literally see more performance in games with faster RAM. Decreasing data movement would objectively lead to more performance, especially they can do it without increasing latency.

Maybe it'd only be 5%, but people pay hundreds of dollars on binned ram for gains less than that.

We're so lucky that clam also does per-workload cache hitrate breakdowns that for some reason you forgot to poast.
Wonder why.

you can post them? If theres one thats really relevant you should share because that would actually be helpful instead of talking down to me and being toxic?

idk why you're trying to call me out, I have no agenda here, just discussing the theory. literally not withholding anything

 

[CouncilorIrissa]

nah, X3D CPUs literally see more performance in games with faster RAM.

That's because it reduces latency in the 96MB+ region with no downside in the sub-96MB region.

especially they can do it without increasing latency.

You can't defy physics, engineers aren't magicians. 1-hi V$ already has a 4 cycle penalty. When going from 32MB to 96MB, those 4 cycles are worth the hitrate surplus. When going from 96MB to 160MB, that surplus is smaller, which might render the additional hitrate pointless in a lot of scenarios due to additional latency.

Maybe it'd only be 5%, but people pay hundreds of dollars on binned ram for gains less than that.

5% is optimistic.

you can post them? If theres one thats really relevant you should share because that would actually be helpful instead of talking down to me and being toxic?

Here's an example of lost throughput due to additional cycles of latency. Already present when going from 32 -> 96MB.

 

[dr1337]

When going from 96MB to 160MB, that surplus is smaller, which might render the additional hitrate pointless in a lot of scenarios due to additional latency.

you don't actually know that for sure, and even if its 2 (or 8) more cycles, its still 3.9x less latency than hitting DRAM

Here's an example of lost throughput due to additional cycles of latency. Already present when going from 32 -> 96MB.

Its literally not a debate that not all games get a benefit from more cache. hence why AMD moved the cache to the bottom die to offset the clock regressions.


What even was the actual difference in FPS/GPU load with that ratio of cache hitrate and IPC? Probably near 0. 1.73 to 1.77 might as well be nothing.

 

[CouncilorIrissa]

you don't actually know that for sure, and even if its 2 (or 8) more cycles, its still 3.9x less latency than hitting DRAM

I don't need to. It's up to you to prove that engineers (and bean counters) are wrong and the hypothetical 2-hi x3d actually makes sense.

Its literally not a debate that not all games get a benefit from more cache.

So why ask for an expensive product that isn't a universal improvement even hypothetically and actually a regression in certain cases?

 

[dr1337]

So why ask for an expensive product that isn't a universal improvement even hypothetically and actually a regression in certain cases?

Are you asking me why x3d exists at all? this has literally been the case since 2022 when 5800X3D was launched.

I don't need to. It's up to you to prove that engineers (and bean counters) are wrong and the hypothetical 2-hi x3d actually makes sense.

but you're just inventing numbers the same as I am? literally all of this is hypothetical. AMD has no published data whatsoever on extra high cache stacks.