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by TakeBlaster16 1384 days ago
Just adding to what you said, a 24-core CPU won't get anywhere near peak power usage during gaming. Most games only use a handful of cores. The only way you'll approach it is with parallelizable productivity work like video encoding or compiling code.
2 comments

My nephew, B, got his 16+8 i9, during Path of Exile, to peak at 250W, and use all 24 cores. He is running at 5.2Ghz, and using air cooled. We are not sure at all how it uses e-(efficiency) cores, when it has 16 p-cores w/ hyper threading, but it all did show up in the new dark mode task manager.
PoE is one of the few games that actually makes use of lots and lots of cores/threads.
Any idea what for? I feel like PoE doesn't involve that much compute other than what would be offloading to the gpu. Maps are static, and I would have assumed that mobs are primarily computed server-side based on some sort of loosely synchronized state.

I guess I could imagine a few threads for managing different 'panes', a thread for chat, a thread for audio maybe? It's hard to think of 24 independent units of work.

I'm not a game dev, just used to play PoE and curious.

The trick used in AAA is to see each frame as an aggregation of core-independent jobs that can be queued up, and then to buffer several frames ahead. So you aren't working on just "frame A", but also finishing "frame B" and "frame C", and issuing the finished frames according to a desired pace, which allows you to effectively spend more time on single-threaded tasks.

The trade-off is that some number of frames of latency are now baked in by default, but if it means your game went from 30hz to 60hz with an frame of delay, it is about as responsive as it was before, but feels smoother.

Sure that explains the parallelization, but not why it takes 250 watts worth of compute to run the game. What's it computing?
The next frame.
if it's anything like gta5 it's going to be calling strlen a billionty times
Can you provide some more info about this?
Could it be the gpu driver/framework? I thought DX12 and Vulkun were meant to be cpu optimised and be able to use heaps of cores.
I guess, but like... how? Like I said, I can't really think of 24 things to do lol. I'm reminded of Dolphin, the GC/Wii emulator - people would ask for more cores to be used and they'd basically be like "for what???", they started moving stuff like audio out, eventually they made some breakthroughs where they could split more things out.

Maybe with these frameworks threads are less dedicated and instead are more cooperative, idk. Really not my area!

https://m.youtube.com/watch?v=MWyV0kIp5n4 I'm reminded of this poe build that can crash the server with too many spell effects
Maybe all it does is produce crazy high, pointless FPS.
I've seen the NVIDIA driver eat up all the CPU on multiple cores without really doing anything substantial to the framerate.

This was back in the Windows XP days when I was working on OpenGL and DirectX. It would do this while rendering like a couple of triangles. One core I could understand, but not all. I'm pretty sure the driver had some spinlocks in there.

I also managed to find out the NVIDIA driver assumed user buffers passed to OpenGL (VBOs) would be 16-byte aligned, using aligned SIMD operations on them directly, even though there's no mention of alignment in the OpenGL spec.

It just so happened that Microsoft's C++ runtime would do 16-byte aligned allocations, while the language I was using only did 4-byte.

All is fair in love and performance wars I suppose...

What’s a new dark mode task manager?
The latest Windows 11 preview finally reads the system default paint allowing “dark mode” rendering the ui with dark background and light foreground.
So like in win 95 when you use a "dark theme". What an achievement. Wait, you can also set background colour. /s
What a time to be alive!!
I think you'll find that modern games use many more cores than they used to since mainstream consoles have all moved to being octa-core for the last two generations and you have things like Vulkan better allowing multi-threaded graphics code.
Many more cores yes, but 100% CPU usage should still be rare. If your game uses 100% of a 24C/32T processor, it will run poorly on a "mere" 8-core CPU, and most of your target audience won't be able to play it. You're right though, these aren't your grandma's single-threaded games anymore.