Sand King's Sand Storm visual/particle effect causes a Huge frame drop in-game.

[deanrih]

Your system information

• System information from steam (Steam -> Help -> System Information) in a gist: https://gist.github.com/deanrih/72da4722d51347c6a4322f1ba3b4804b
• Have you checked for system updates? Yes
• Are you using the latest stable video driver available for your system? Yes
• Have you verified the game files? Yes

Please describe your issue in as much detail as possible:

Sand King's Sand Storm effects causes huge frame drop from 90FPS (Purposely Limited) to around 30FPS, and happened in Demo Hero, Normal Match and Aghanim's Labyrinth, on Aghanim's Labyrinth especially, since there's a shard that can cause multiple Sand Storm to appear, it can drop to below 10FPS, I have seen even the game render at 8FPS. Keep in mind that this is not happening on OpenGL.

I have attached the System information, but for quick reference, I have RTX2060, Core i3 8100 and play the game at 4K and Max FPS limited to 90, also enabled AMD FSR at 60% render, all graphic settings set to Max or Enabled except VSync.

Describe what you expected should happen: The game should maintain it's FPS similar to using OpenGL whenever Sand King casts his Sand Storm ability. What did happen: The game FPS drop to around 30FPS on normal dota matches, and can go below 10FPS on Aghanim's Labyrinth games whenever Sand King casts his Sand Storm ability.

Steps for reproducing this issue:

1. Open Dota 2 with Vulkan API (Also note that both on Vulkand and OpenGL the main menu is extremely heavy, only renders at ~35FPS, worse on OpenGL at ~20FPS)
2. Go to Heroes tab
3. Choose Sand King
4. Go into Demo Hero
5. Level up Sand Storm
6. Casts Sand Storm
7. Or play Aghanim's Labyrinth (preferably through console commands for making private session for testing)
8. Choose Sand King
9. If available take the shard that casts additional Sand Storm
10. Try to trigger the shard so more than one instance of Sand Storm present

[bajidu]

The same issue should arise using butcher's agha upgraded rot. Can you confirm @deanrih ?

[F1am]

I have the same issue on Linux mint 20.3, 1070 card. Using driver version 470 fixed the issue, any version above had massive fps drops.

[deanrih]

@bajidu

The same issue should arise using butcher's agha upgraded rot. Can you confirm @deanrih ?

Unfortunately I'm unable to replicate the issue with Pudge's Rot either with or without Aghanim's Upgrade. The FPS stays at 90, the only thing I realize it drops slightly and quickly from 90 to around 60~70 and back up to 90 when the ability switches it's state, e.g from active to inactive and vice versa. But it is seems to be "normal" behavior every time a spell being casts.

[deanrih]

I have the same issue on Linux mint 20.3, 1070 card. Using driver version 470 fixed the issue, any version above had massive fps drops.

Interesting, I was using 470 too but the Sandking's VFX dropping the frame, so I tried updating my driver to the latest hoping it will fix it. The certain thing is it is only happening in Vulkan (hence the repository here), it's either Source 2's Vulkan implementation fault or the Sandking's VFX isn't optimized.

[F1am]

I can confirm this only happens with vulkan and have only seen the issue with sandstorm

[danslo]

Confirming this issue on Ubuntu 21.10 with nvidia-driver-510 (RTX 3070).

[voronind]

I can confirm it for OpenGL and for other spells with semitransparent visual effects. Sandstorm demonstrate maximum frame rate dropdown.

[deanrih]

I can confirm it for OpenGL and for other spells with semitransparent visual effects. Sandstorm demonstrate maximum frame rate dropdown.

That's weird, I have no issue on OpenGL other than general poor performance compared to Vulkan, but even that OpenGL managed the FPS steady when casting Sand King's Sand Store, especially on Demo Hero mode you spam the Sand Storm ability.

But what I do notice is when switching from Vulkan and OpenGL, on OpenGL the Sand Storm and/or Pudge's Rot drop the FPS down on their 1st time cast, probably shader compilation, after that, it stable unlike in Vulkan, very noticeable if you spam Sand Storm (Pudge's Rot somehow not affecting performance)

And since it is, at least for me, only happened on Vulkan, that's why it is reported here.

[deanrih]

Additional information I wanted to confirm.

After the recent update, the Sand King's Sand Storm seems to be more stable, but if you go to Demo Hero, activate Free Spell and spam the Sand Storm ability, the FPS drop still occurs, yes it is unrealistic but the thing is, it didn't happen on OpenGL.

Also on an unrelated note, I notice that on Vulkan if you have more than 2 or maybe more than 1 bounty rune laying around, e.g for example 4, and you activate them all, FPS going to drop, but not that significant.

[deanrih]

Closing this since it seems the problem has been fixed either by Dota 2 updates or by the GPU driver.