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readthenotes1today at 5:50 AM4 repliesview on HN

Can you quantify those performance problems? Would I notice them on a 2018 vintage laptop?


Replies

Fiveplustoday at 5:54 AM

Hmm, I'd say that on a 2018-era machine, you won't measure this in raw CPU throughput. In all probablity, your cores are fast enough to mask the context switching. The performance deficit here is strictly in the domain of motion-to-photon latency or frame pacing. I guess my point is that in xfce's split architecture, the compositor acts as just another X11 client.

This enforces a path where window contents often round-trip through the X server before composition. Quantitatively, this typically adds at least one frame of input lag compared to the zero-copy direct scanout path available to monolithic wayland compositors. You likely won't notice this while editing text. However, the architecture doesn't perform well when you attach an external monitor. Since X11 shares a single virtual coordinate space, it cannot synchronize VBLANK across two outputs with different refresh rates or clock domains.

ps: and please don't call your 2018 machine vintage, it makes my secondary thinkpads feel prehistoric :D

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getcrunktoday at 5:54 AM

Just thinking out loud here, but even if it’s a performance anti pattern, xfce is a light weight de so you wouldn’t see it over all I guess.

To my eye most Linux de’s are much lighter or responsive than windows or Mac

margalabargalatoday at 6:19 AM

As someone who runs modern XFCE on a core 2 duo I still have without noticable perf issues, the problems the parent talks about are theoretical and not observable.

FlyingSnaketoday at 6:19 AM

I am running XFCE on a 2019 vintage desktop. CachyOS and 16GB RAM. It is snappy and very performant for my needs and I work on it daily for software development

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