6 ms·
AnandTech sees some intriguing regressions on certain benchmarks, https://www.anandtech.com/show/18747/the-amd-ryzen-9-7950x3d-review-amd-s-fastest-gaming-proc
by perihelions 4y ago
AnandTech sees some intriguing regressions on certain benchmarks,
https://www.anandtech.com/show/18747/the-amd-ryzen-9-7950x3d-review-amd-s-fastest-gaming-processor/4 https://www.anandtech.com/show/18747/the-amd-ryzen-9-7950x3d... ("CPU Benchmark Performance: Simulation")
Worst is Factorio, which is down -47% against the 5800X3D (a previous-generation CPU that also uses stacked L3 cache), on the benchmark "10K trains". Wonder what's going on there?
- "We would have expected higher performance in our Factorio benchmark, as the Ryzen 7 5800X3D and its 3D V-Cache did yield some impressive gains. This is likely due to the AMD PPM Provisioning and 3D V-Cache driver opting for frequency over cache when running this benchmark."
- sct202 4y agoI saw on Hardware Unboxed that the non-X3D cores were being used for Factorio and that reviewer manually disabled it to test correctly.
- shock-value 4y ago[flagged]
- likeclockwork 4y agoWhat driver is responsible for assigning specific games to specific CPU CCDs? Is this a real thing? Is it available on Linux? Or am I sticking with Intel?
- goosedragons 4y agoIt's the CPU scheduler. You can easily avoid this by just not buying an X3D variant. Recent Intel CPUs can have the same problem where processes get assigned to the efficiency cores instead of performance cores if the right scheduler isn't used (like by using Windows 10 or an old Linux distro without explicit support)
- likeclockwork 4y agoAnd there's actually a list of blessed processes in the scheduler?!
- kllrnohj 4y agoKinda. It's more like "if windows game bar shows up -> restrict to cores 0-7"
- kllrnohj 4y agoOr buy an X3D that's homogeneous, like the 5800X3D or upcoming 7800X3D. I have no idea why AMD made the 7950X3D be this weird 50/50 split. Why not make both CCDs have 3D V-cache and make it the true halo part it should be? Then cut costs with the 7900X3D?
- mort96 4y agoThe added cache isn't free; the CCD with vcache runs at a significantly lower clock speed. If every task was always put on the most appropriate CCD, the heterogeneous approach is pretty much a direct advantage, as frequency-sensitive workloads get high frequencies and cache-sensitive workloads get lots of cache. Whether it will ever get good enough at picking CCD remains to be seen though.
- kllrnohj 4y agoPerhaps but I have no idea how any scheduler can possibly figure out if a workload is frequency or cache sensitive. The current strategy seems to be "if game, use cache, else use frequency" and it sorta works OK-ish? Although then there's games that aren't detected right (like Factorio) and it's then a terrible result. But if you look at single threaded results with it set to "prefer cache" it's not really that much slower. Yes you'd have a flagship with lower single-threaded Cinebench results, but I mean that also happens with pretty much every HEDT platform and nobody bats an eye at that. The results are still a significant step beyond the 5000 series single core results.
- 4y ago
- W1zzardTPU 4y agohttps://www.techpowerup.com/review/amd-ryzen-9-7950x3d/5.html https://www.techpowerup.com/review/amd-ryzen-9-7950x3d/5.htm...
- deleted 4y ago[deleted]
- jrmg 4y agoIs there a point to going beyond 60 updates/s in Factorio? Because if not the system seems to be doing the correct thing and using less power. I hope AMD isn’t causing higher power usage for all users just to game some benchmarks!
- Filligree 4y ago60 updates/second only happens while you're still running a small base.
- FeepingCreature 4y agoIt's not like the CPU looks at the FPS to decide how to clock. Factorio has extremely variable CPU demand as your base grows.
- jrmg 4y agoModern CPU and scheduler combos will in fact try to do that or, at least, do something that has that as a second order effect. They’ll try to run the CPU at a speed that evens out regular bursts into steady loads, on the lowest power core on which that’s possible to do. Edit: although, for that to work for this workload Factorio itself would need to be updating at a steady 60 updates/s, which I guess is not actually the case here…
- FeepingCreature 4y agoI mean, sure, if Factorio was running at 60 stably the CPU would downclock until it was just about keeping up. My point is more that artificially running Factorio at unlocked tickrates (above 60) makes sense for a benchmark, because if it can hit 115 in that map that tells you it'll be able to keep 60 in a map that's twice as big. Ie. I'm saying it's not like the CPU is using a different mode below 60 and above 60 as long as the tickrate is unlocked; there's nothing special about 60, it just happens that's what Factorio is normally limited to.
- jnwatson 4y agoMegabases can get quite processor intensive. Small bases with high ups are a proxy for megabases with reasonable ups.
- brucethemoose2 4y agoFactorio (unfortunately) isn't a very typical benchmark. The "run AAAs at low graphics at 1080p" trend among review sites is kinda stupid though.
- deleted 4y ago[deleted]
- drewg123 4y agoWhen they manually forced it onto the CCD with 3D-Vcache, they saw a 100% speedup: "As we can see in our Factorio benchmark, we saw massive gains of over 100% when forcing the Ryzen 9 7950X3D to use the CCD with the 3D V-Cache as opposed to letting AMD's PPM Provisioning and 3D V-Cache Optimizer drivers do their thing automatically."
- perihelions 4y agoOh good catch! I didn't read that far. It's on page 11: https://www.anandtech.com/show/18747/the-amd-ryzen-9-7950x3d-review-amd-s-fastest-gaming-processor/11 https://www.anandtech.com/show/18747/the-amd-ryzen-9-7950x3d... ("Conclusion")
- guilamu 4y ago5800x3D has a single CCD so no need to choose which CCD to use. The interesting one will be the 7800X3D.
- HelixEndeavor 4y agoSo presumably a bug that can be fixed by either AMD updating their optimizer, Factorio updating to work better with it, or both?
- moffkalast 4y agoIf it's a problem for Factorio it's also a problem for others, so definitely something to fix on the AMD side.
- brucethemoose2 4y agoIts more of a fundamental scheduling issue. The unlike big/little cores OS has no idea what apps "prefer" cache or frequency.
- londons_explore 4y ago
- BackBlast 4y agoDepends on good scheduling choices since some threads benefit from the higher clocked CCD and others benefit from the higher cache CCD. Sounds like AMD is using a lookup table style scheduler on windows. I believe the system mostly schedules the higher clock CCD by default. Similar problem to big.little but less differentiation between the cores. It's big.big. Kind of a mess outside of the primary use case that is games on windows with a static tuned scheduler.
- amrb 4y agoIts worth say that the 3D V-Cache is only on the left of the two dies, while the other is frequency unlocked. Also linking my favorite tech reviewers benchmark they do some great Linux/tech videos also! https://www.youtube.com/watch?v=jNMcdIkef_c https://www.youtube.com/watch?v=jNMcdIkef_c
- shmerl 4y agoLinux video here: https://www.youtube.com/watch?v=5yDsEbSxHkM https://www.youtube.com/watch?v=5yDsEbSxHkM
- bick_nyers 4y agoI didn't read the article but according to Gamers Nexus latest video you REALLY need the latest BIOS and Chipset drivers for this part because it is what tells Windows which CCD the game threads should be parked on.