I noticed a few instances where the emulation goes from 100% speed down to 5% or something and the game almost looks like it hangs or goes in slow motion, without necessarily using 100% of the CPU. This happens in OpenGL and in order to pass those instances, i have to change to software mode with F9 (yes, in SW it runs faster)
This happens in Grand Turismo 4 when you select a car and in ZOE 2, level 2, when the "mummyhead" enemies appear.
I have an i5 4670, GTX 960 and Windows 7 SP1.
there's a new pull request on plans to increase the speed when using OpenGL with Blending unit accuracy :
#1015
The question is does it run faster without accurate blending? If yes, which level trigger the slow down.
Well it is easy to separate both issue. Is the speed issue appears in native resolution?
(note, missing vram usually crash on openGL).
Yes, it's the blending accuracy option. I have it on the recommended setting (basic) and it slows down these games. Doesn't matter if i use other options to speed up, like native resolution or steal VUs. Only if i disable blending accuracy these games stop suffering from these hangs.
Ok. FWIW, there is a new hack to accelerate it + a new PR that will improve the speed further. I'm not sure it will be enough. It really depends on the games. Some games can uses high with a very limited speed impact. Some games don't like it.
The PR was merged, please retry a new build. And try also the new hack too.
In GT4, I have been experimenting with the fast accurate blend hack as well as accurate date on the track selection screens. The results I got were pretty interesting.
First and foremost, I have fixed the transition slowdown by disabling Hardware Depth. This setting alone kills fps in the menus and races in GT4.
Here are some other tests I conducted while on the vehicle selection screen.
Control (No Accurate Date, No Fast Blend)
Basic ~58-61fps
Medium ~57-61fps
High ~20-37fps
Full ~20-39fps
With only Accurate Date
Basic ~53-58fps -
Medium ~ 53-58fps -
High ~ 50-55fps +
Full ~50-55fps +
With only Fast Accurate Blending
Basic ~58-61fps - No Change
Medium ~58-61fps - No Change
High ~20-39fps - No Change
Full ~20-40fps - No Change
tl;dr - Try disabling Hardware Depth and see if the slowdowns still occur. Fast accurate blending had no effect regardless; but Accurate Date might help on High/Full.
i dunno, looks like you gained a couple of FPS with fast blending when doing high and full settings
