I have been playing MC forge with optifine for a few days now and noticed that I was using my Integrated graphics instead of my dedicated one. I usually got around 40-60 fps which is playable but not great. I switched to my dedicated MX-150 2 card and instantly got to around 80-130 fps which is much better. The only problem is that after around 2 minutes of playing, my fps drops to like 10-20. I looked at Task manager and saw that only around 40-50% of my GPU was actually being used. My fps is also not going back up.
The first screenshot is when I am starting the game
I have been looking around the internet but can't seem to find anyone who has encountered the same problem and gotten a good solution. I hope that someone here might have an idea of what might be going on and how to fix it!
minecraft is a cpu bound game one core usually so if your cpu is slow or heavily loaded and your pics show 100% use at times this kills framerate also if your drive is slowish it can cause lag/slow framrates too a good gpu wont matter much in ether case. also your cpu is running at .6ghz (600mhz in the second pic) if minecraft is running when the task manger pic was taken then your laptop maybe overheating may want to look into that just in case. only time ive seen a intel chip clock that far down with any load is when its thermal throttling hard id bet near 90-100C can confirm this with hwinfo or another program that can read the cpus temperature.
While it could be my CPU I highly doubt it since it can handle minecraft with no problem with my integrated graphics card. It is only when switching to my dedicated one that fps goes down. I did some further testing and took a few screenshots.
As you can see, when using the integrated card, 100% is being used at almost all times:
I'd definitely check to see if its running hot as your cpu speed numbers are hinting strongly at heat issues.
i am fairly positive your cpu is throttling pic 1 and 2 are running at 2.60-2.65 ghz and the third after the heat builds up a bit is at 1.6 ghz if you let it run longer it will get slower aka first post second pic 0.6ghz this is telling me that its a heat problem.
my guess at the issue is your heat sinks are getting close to or are plugged and/or your fans are not spinning up as there supposed too.
also your ram use is is quite high and you may be getting slowed by things swapping from your hdd/ssd to ram and back!