Full speed with SW rendering, slow with HW

[Dr_Hycodan]

Something isn't quite right, I'm getting full speed on every game with SW rendering, while HW is quite slow on some games like Okage shadow king and MGS2.  And the weirdest part of all, I'm on a geforce gtx 980, one of the fastest gpu's out you can get.  Now, I am using OpenGL with HW depth, HW date, and high accuracy blending, but I do have very high end specs here.  Is this normal for high accuracy blending to be that slow?

[jesalvein]

Something isn't quite right, I'm getting full speed on every game with SW rendering, while HW is quite slow on some games like Okage shadow king and MGS2.  And the weirdest part of all, I'm on a geforce gtx 980, one of the fastest gpu's out you can get.  Now, I am using OpenGL with HW depth, HW date, and high accuracy blending, but I do have  very high end specs here.  Is this normal for high accuracy blending to be that slow?

Yes. It's a very demanding feature, especially on some games

[FlatOut]

You don't need HW depth, accurate date and b.u.a. on/high for every game, it can even cause crashes or create bugs that aren't there without 'em. And then there's the speed issue.

[gregory]

high accuracy blending

Require a beefy CPU (and a 20% increase on the GPU). It is slow because it emulate a missing hardware feature. It will be less slower when the feature will be fully available in the hardware (but someone will need to code it).

[Dr_Hycodan]

But I'm on a i7 skylake, isn't that beefy enough?

[tsunami2311]

But I'm on a i7 skylake, isn't that beefy enough?

nope, pretty sure there games out there that isnt a enough, majority of games yes

[gregory]

I said beefy CPU not a slow CPU

I'm on a geforce gtx 980, one of the fastest gpu's out you can get

In order to emulate a perfect blending, I need to flush the GPU cache every primitives. So paradoxically it will be slower on your GPU. Big GPU means big cache, means more to invalidate, means slower performance.

(long term) Future GSdx will rely on GPU hardware rather than trying to emulate it so it would be faster. But don't expect it soon, I likely won't upgrade my GPU this year.