GPU Bottleneck?

[anaid]

(11-25-2013, 08:56 AM)NaturalViolence Wrote:

anaid Wrote:Your latter statement is true, the desktop i3 indeed perform better than the laptop Core 2 Duo. But your statement about CPU bottleneck in my laptop, is there anyway to confirm that? Because the CPU utilization monitor sure tells a different story....

Assuming LLE on thread is off dolphin uses two threads/cores. Main and video. The Main thread could be bottlenecked by cpu performance while the video thread is not. Or vice versa. This would result in one core at 100% usage and another core with a low utilization. Resulting in a total utilization that is not 90-100% despite a cpu bottleneck being present.

It could also be a GPU bottleneck. Newer builds are generally more demanding on GPUs.

If we still had the lock threads to cores option that would be perfect for diagnosing this....sigh. Since the threads bounce back and forth without that option I don't see a simple way to measure actual per thread cycle usage.

anaid Wrote:Hi Anti-Ultimate , I don't know about actual comparison in terms of IPC, but from a MIPS (million instructions per second) perspective, new generation Core i7s (~14k MIPS) are not THAT big of a leap from the Core 2 Duo (~11k MIPS), from my numbers its approximately 30% more.

MIPS is entirely relative to the application. As is IPC.

If you're comparing two microprocessors processor B could have 30% higher IPC that processor A in one application while having 210% higher IPC in another application. Depending on what kind of code those applications execute and how the microarchitecture is setup to deal with them.

anaid Wrote:Though I don't know the exact process flow of Dolphin. But a slow processor should not limit how well Dolphin utilize the CPU.

That's not entirely true. See above.

Hey NaturalViolence. Thanks for your input, I learned a lot from what you said. I totally get why CPU utilization can not fully reflect CPU bottleneck now.

On a side note. I ran some test with the OpenGL Driver Monitor with Xcode. Dolphin 4.0-rXXX is indeed more demanding in terms of GPU core utilization. However, for some reason it almost doubled the "CPU wait for GPU" time required when comparing to Dolphin 3.5.

Not sure if it is due to poor hardware performance on certain OpenGL functions calls, or poor optimization of Dolphin.