| 2 Dec 2025 |
 niklaskorz | afaik the Steam Deck also defaults to scx_lavd | 15:23:23 |
 Marie | is that also the case for letting a game run only on the cores with bigger cache on X3D cpus? | 15:28:52 |
| Marie | thats basically the only reason why i use gamemode | 15:29:09 |
 K900 | ish | 15:29:55 |
| K900 | The kernel will just generally prefer the big cache cores | 15:30:03 |
| K900 | Unless configured to do the opposite | 15:30:07 |
| K900 | It doesn't technically differentiate workloads but it also doesn't really need to | 15:30:40 |
| K900 | Not yet | 15:30:47 |
| K900 | But they're working on making it an option | 15:30:53 |
| K900 | Presumably with eyes towards eventually defaulting to it | 15:31:01 |
| niklaskorz | oh I see, I assumed since Jovian defaults to scx_lavd that was copied from what SteamOS does | 15:31:19 |
| K900 | Jovian doesn't | 15:31:31 |
| K900 | We install it, but don't enable it | 15:31:36 |
| K900 | So steamos-manager can enable it | 15:31:46 |
| niklaskorz | https://github.com/Jovian-Experiments/Jovian-NixOS/blob/1127a4fc66425cceae683becb93f038819cf2633/modules/steam/steam.nix#L58-L61 | 15:32:01 |
| niklaskorz | services.scx = {
enable = lib.mkDefault true;
scheduler = "scx_lavd";
};
| 15:32:11 |
| K900 | systemd.services.scx.wantedBy = lib.mkForce [];
| 15:32:18 |
| K900 | I wrote that code | 15:32:20 |
| niklaskorz | hah I missed that part | 15:32:46 |
| niklaskorz | I know | 15:32:50 |
| niklaskorz | if you mainly need it for Proton games you can use the PROTON_CPU_TOPOLOGY environment variable to force them to run on the big cache cores | 15:34:37 |
| niklaskorz | on that note, thanks for the great work, I've been studying it a bit over the past week and it's a great resource | 15:37:11 |
 Sean | hmm interesting. mind sharing? I also have 3D cache but I've been using lavd | 15:49:21 |
| niklaskorz | for the 7950X3D it's PROTON_CPU_TOPOLOGY = "16:0,1,2,3,4,5,6,7,16,17,18,19,20,21,22,23" | 15:50:38 |
| Sean | how do I figure this out? I have the 5700x3d | 15:51:03 |
 Sandro 🐧 | yeah, that works I am very sure | 16:03:31 |
| K900 | You don't need it | 16:04:34 |
| K900 | You just have 8 cache cores | 16:04:46 |
| K900 | The 16 core X3D parts have 8 cache cores and 8 no cache cores | 16:04:55 |
| niklaskorz | but if you ever come upon a multi CCD processor with different L3 cache sizes, you can check out lstopo in the hwloc package | 16:07:59 |
