Is it normal that...

[Matthias]

Then you don't know much about memory, memory stays. I even did this to my MP3 player once, it wouldn't start.
But after removing the battery and letting it just lay there for a few hours cleared it's internal memory and there we go again.
It works for mobiles displaying the battery wrong and even electronic speed meters displaying speed wrong.

MP3 player != PC! And what bluefox said etc.

[0Target0]

Capacitors ftw!

[[Jordan]]

Afaik minecraft takes more memory as time goes, as do many other applications.
If the memory runs out, it will start using the HDD instead, which will go very slow.
On older computers it's a good idea to shutdown, pull the power cable and let it stand for 1-2 hours.
Doing that will free up on memory.

1. CTRL+ALT+DEL to bring up the task manager when your computer is lagging.
2. Find minecraft under Applications, right click it and choose "Go To Process".
3. Check how much memory it's using and report back here.
4. Check CPU Usage at bottom and report back here.
5. Which process is using the most CPU?
6. Press Performance tab, report the following values: "Total", "Cached", "Available" and "Free" under Physical Memory.

If RAM isn't the issue, it could be overheating, things do run slower on higher temperatures.

3. 569,000 K and rising
4. ~50% CPU Usage
5. differs between System Idle Process and javaw.exe
6. Total: 1046604, Availible: 40928, Cache: 65580 (approx)

[iou]

3. Looks pretty normal.

4. Then we can rule out the processor.

5. System idle process is just a counter showing how much of your processor is idling, so when anything goes up, that one goes down and vice versa.

6. Is it counted in MB or KB? It's a shitload if it's MB lol.
This may depend on the OS, Win7 shows MB anyway "Physical Memory (MB)".

As for 3 I need to know if 6 was counted with MB or KB.

[[Jordan]]

Nah its KB, windows XP.

[iou]

Definitely a memory issue.

Converted to MB:

Total: 1022 (1 GB)
Available: 39
Cache: 64

I'm guessing that minecraft is what's taking so much, to be sure check the memory of javaw.exe under Processes and report back here.

39 MB left isn't very solid, the hard drive will be put to work.

[[Jordan]]

Definitely a memory issue.

Converted to MB:

Total: 1022 (1 GB)
Available: 39
Cache: 64

I'm guessing that minecraft is what's taking so much, to be sure check the memory of javaw.exe under Processes and report back here.

39 MB left isn't very solid, the hard drive will be put to work.

I did,

3. 569,000 K and rising

[iou]

Ah yeah, I missed that.

Minecraft is using about 555 MB in that case (half of your total memory), 39 MB more and your computer will need to use your hard drive.
A memory upgrade or perhaps a new computer should solve your problem.