HAGS On or Off?

[fearlessfrog]

HAGS!

Windows Hardware Accelerated Graphics Scheduler of HAGS is a bit of a mystery. It’s off by default (you can turn it on in Display settings / Graphics Settings sub-menu) and apparently it should speed up stuff to be given to the GPU to munch on. It has always seemed ineffective.

Here’s a tech write up for nerds of what it’s trying to do:

Hardware Accelerated GPU Scheduling

Here’s a review of a bunch of games where it doesn’t really help, and in some cases makes worse:

Windows 10 Hardware Accelerated GPU Scheduling Performance Analysis

So I thought I’d at least try it again with the most recent driver and my ‘house or GPU’ priced hardware - perhaps things are better?

Here’s a quick CapFrameX run with HAGS off and then HAGS on, in VR using the OpenXR NIS of 80%. This is from a 60 second capture average of a freeflight in a C152 over YVR in real weather - the exact settings aren’t so important more that just the single HAGS setting had changed between runs.

So HAGS On is a bit slower still.

Perhaps it makes games smoother, in that a lower average FPS but steadier frames?

Here’s HAGS off:

…and On:

So I did have a ‘glitch’ that threw the smoothness average out a bit, but I lost quite a bit of framerate for that, and who knows if that spike was HAGS helping?

Let’s take out that glitch with the Interquartile view with a frame timing view. HAGS off:

HAGS on:

Hmm, that’s the same amount of framerate consistency I think?

So in summary - HAGS off you go… Perhaps better in Windows 11?

Anyone use it?

[jross]

@fearlessfrog

Anyone use it?

Not yet. But I did think about it (new box, Win11). Turning it On that is. I’ll try in a bit, on my next test run…

I’ve “heard” very recently that the new nVidia 511.xx driver, perhaps in Win11, now actually does something positive. Will see.

[Edit]…(sing along with me)…“off we go, into the virtual blue yonder, flying high…”.

[HiFlyer]

This issue is probably going to become as much a matter of choice as Affinity masks, and hyper threading.

[jross]

DCS Test.

Ok, seat of the pants test: no noticeable difference. With HAGS = On I did get a blue screen while it tried to load a dense urban scene but that could be a SteamVr/WMR/LMNOP thing. It came back within a second. Not scientific, more a a WAG on HAGS Couldn’t resist.

[Aginor]

I say no to Hags.

[fearlessfrog]

I tried a few different ways a some more games and I just can’t get any improvement out of it. I think it’s a good idea, but the trouble is that games when they get tested and profiled before release already have to deal with the CPU → GPU instruction buffer without HAGS. No-one is going to release a title that relies on there being a hardware scheduler (because they all use a buffer anyway), so any bottleneck around GPU instruction hand-off has to be sorted out assuming HAGS doesn’t exist.

Oh well, at least good to know for sure.

[jross]

@fearlessfrog

No-one is going to release a title that relies on there being a hardware scheduler

Excellent point that one.

[Chaz]

Been off for me for awhile. It caused major stuttering while looking left and right in DCS. Haven’t touched it since.

[jross]

@Chaz

It caused major stuttering while looking left and right in DCS.

Might have been that ‘blue screen’ thing I spoke of before - in fact I had turned my head down & right towards a dense area when that happened. But I can say I tested it. Once.