AMD Ryzen 7 7800X3D Linux Performance

[smitty3268]

taskset has got you covered.

Truth to be told, neither Intel, nor AMD care too much about Linux. The Linux kernel still doesn't properly support ADL which will soon turn two years of age. I guess the X3D parts will meet the same fate.

I believe all they've done on windows is hardcode a list of .exe files they want to prioritize towards the cache.

I wouldn't expect anything official from AMD on linux, but it should be fairly trivial to accomplish the same thing using Feral's gamemode daemon and that wouldn't require any input from AMD. Could even be better than windows since it could be crowdsourced rather than needing AMD to care enough about an app to include it.

[Paradigm Shifter]

Well, other reviews show this to be an impressive gaming CPU, but it's not going to win any awards for productivity. That said, it's a 65W part which is getting rather close to CPUs drawing much more power.

IIRC, the (relatively) high idle power is from that I/O die. Dropping the voltage on it a tiny bit (from TechPowerUp) might help somewhat without compromising stability (but of course it will depend on the individual CPU).

I'll get this or a 7950X3D, whichever comes into stock here first. Either will let me play with what I want do do.

[rclark]

Unless something breaks bad here on my Ryzen 5xxxx series Linux desktops, I'll hold off upgrading ... at least this year. I just don't have a need for 'more' anything right now (Ie. I have no applications or VMs that are 'slow' to 'do' anything... Everything is just 'quick' ... zip zip zip). I'll see how things look come about this time next year . That said, I do like what these X3D chips bring to the table for even general computing (I don't 'game'). With the low power consumption, air coolers look like they should work too. I don't like 'pumps' in my system if I can help it. I'd go for the 7950X3D and/or the 7800X3D if needed by then ... Who knows though as AMD may have another round of CPUs queued up, and the AM5 platform should have more than matured by then with plenty of BIOS and OS software support along with it.

[sobrus]

New CPU scheduler/driver won't do anything to idle power savings, because the power comes mainly from SoC, not the CPU cores.
For example, my 5959x with 128GB RAM (4 dual rank sticks) @1733 memory and if clock idles happily at 40-100Mhz, ~0W core power, 26W package power, BUT SoC can't take less than 15W (more when memory and/or GPU is used). It's enough to downclock memory to 1333Mhz to drop power by almost 10W.
It is also visible on screenshot by numacross - his core power is 0.05W, but SoC power is 5W, and total package power is 12W .
It will also consume less with less ram or single rank sticks, more with higher bus /mem clocks (but you probably can't do 1800Mhz with 4 dual rank sticks anyway).

Moreover, some motherboards, like my B550 Aorus pro ax, set soc to overclocking mode as soon as you enable XMP. In this mode soc clocks and voltage are permanently maxed @1.2V and idle power can be even MUCH higher.

So if you want low idle power consumption make sure you
1) don't enable XMP, just set timings and frequency manually
2) don't have 4 sticks of ram, especially dual rank ram (=quad rank if 4 sticks used)
3) undervolt your SoC - even though the memory controlled is really maxed out in my setup, 0.968V is just fine,
4) lower your IF/memory frequency
5) make sure you don't have uncore oc mode enabled anywhere in your BIOS (or check SoC Voltage, shouldn't be @1.2V)

Don't know about ryzen 7000, as it uses DDR5 and has brand new memory controller in newer litography, but the same basic rules probably apply. Probably mobile Ryzens don't use 1800Mhz IF to achieve lower power consumption.

[Eirikr1848]

Do the 2 GPU cores also benefit from the higher cache?

[Keats]

Well, other reviews show this to be an impressive gaming CPU, but it's not going to win any awards for productivity. That said, it's a 65W part which is getting rather close to CPUs drawing much more power.

IIRC, the (relatively) high idle power is from that I/O die. Dropping the voltage on it a tiny bit (from TechPowerUp) might help somewhat without compromising stability (but of course it will depend on the individual CPU).

I'll get this or a 7950X3D, whichever comes into stock here first. Either will let me play with what I want do do.

The performance per watt charts are kind of misleading for the other Zen4 CPUs. Anyone who cares about that should either get a non-X SKU or turn on ECO mode.

Do the 2 GPU cores also benefit from the higher cache?

Nope. The GPU cores are part of the I/O die and have their own cache so get no (direct) benefit from the extra L3.

[L_A_G]

Many of us use our computers for things other than gaming, so these benchmarks are very useful to see if this processor is a fit for our tasks. Sadly most review sites will mostly benchmark games, so it's nice to have Phoronix benchmark beyond that.

If you read my post properly you'd have noticed that I didn't wonder why Michael ran productivity tests at all, but that the focus wasn't on what this CPU is sold for and what it's also best at.

[blackshard]

taskset has got you covered.

Truth to be told, neither Intel, nor AMD care too much about Linux. The Linux kernel still doesn't properly support ADL which will soon turn two years of age. I guess the X3D parts will meet the same fate.

Ssssh, don't tell Valve AMD does not care about Linux... they based their steam deck around their SoCs...

Irony apart, there have been several phoronix news in the years telling about the finetuning around AMD pstate driver and its purposes that make your statement partially preposterous.

[avis]

Ssssh, don't tell Valve AMD does not care about Linux... they based their steam deck around their SoCs...

Irony apart, there have been several phoronix news in the years telling about the finetuning around AMD pstate driver and its purposes that make your statement partially preposterous.

My preposterous statement is based on the GIT commit commit history for this driver. Nice insult BTW. Sneaky and vile.

Here, enjoy full Valve support: https://git.kernel.org/pub/scm/linux...q/amd-pstate.c

Next to zero activity for the past six months aside from a single commit: "cpufreq: amd-pstate: implement Pstate EPP support for the AMD processors".

Kernel bugzilla bugs have seen next to zero activity over the past 12 months.

[qarium]

AMD makes fantastic high-core CPUs.. if you don't game or use Linux .
Their scheduling for the 64 core Threadripper 2990WX was (and still is?) absolutely hot garbage on Windows, with tools like Process Lasso etc. Works great under Linux though.

the 2990WX Threadripper was a 32core cpu... the 64core threadripper was 3000 or 4000 series.