Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Why PCSX2 doesn't use GPU up to 100% when the frame rate limiter is enabled?
#1
I'm playing Dragon Quest VIII but at 4x resolution I can't play it at full speed. The FPS in some scenes is about 50. However, the GPU load according to GPU-Z is only about 70%. If I disable the frame rate limiter, the FPS increases to 72-73.

Is PCSX2 programmed to use the GPU only up to 70% if the frame rate limiter is enabled?
Reply

Sponsored links

#2
Can you please provide your specs? It'll make it easier for use to help as well Smile
-PC Specs-
Intel i5 3570k 3.8Ghz
8gb DDR3 Kingston Hyper X 1600Mhz
MSI GTX 770 2gb OC Gaming Edition @ 1100Mhz
LG Full HD LED 32" Display
Windows 10 Pro x64 
Reply
#3
Yes. I'm using Core i5 2500K, 4 GB of RAM and a 7870. PCSX2 version 1.0.0 with GSdx 5632.
Reply
#4
PCSX2 isn't really programmed in such useless way, on the other hands radeon drivers especially(if not only) at those high end gpu's like hd6800/7800+ tend to have some of it's own problems probably related to AMD extra tries in power saving and the difference between PS2 and PC games gpu limitations. AMD budget gpu's have none of such problems from my own experience;p.
Reply
#5
PCSX2 is a complex balance between different PS2 modules emulation and highly depending on their timings. The percentages seen at the title bar aren't indicative of actual device usage but how much the module is taking from it. For example EE nearing 100% means the core is draining almost all possible available power from the CPU, still that does not mean the CPU is such loaded. PS: What is mean is if the CPU is for any reason underclocked (common in power saving) EE would be taking the most of that underclocked CPU and yet it would appear as almost idle on external monitoring tools, look the example bellow.

The weirdest case of this phenomenon is seen in some combination of Intel CPU + Windows Power management + laptops (although not limited to laptops). The system seems to be oblivious PCSX2 is demanding CPU power and seats there as no loaded at all.

In your case, the low framerate and the GPU is not being totally drained may mean the game's flow (mainly the VUs) aren't being able to provide enough flow to GS. So, the FPS is not determined only by the video card power alone, that's valid for PC games also (sometimes) but is specially true on emulation. One can't try and seek the causes on a module alone but trying to understand that complex balance between them. Similar occurs when GS is nearing 100 and then forces EE and VUs to stall.

That said, is possible the VUs aren't able to keep stead flow, that's where VU cycle stealing may help forcing the EE interruption to send it data when the VU needs them. Or may be the case EE itself is stalling and in this case you may want to use EE cycle rate speedhack.

In fewer words, try the combination of less those two speedhacks which get you nominal FPS. Consider reducing the upscale case using it and try toggling MTVU.

Remember, each game is a case in emulation, don't take for granted that what works for a game is the best for all them.
Imagination is where we are truly real
Reply




Users browsing this thread: 1 Guest(s)