I've recently started having this problem on both my Windows7 laptop and my newly-upgraded-to-Windows7 desktop. One or two instances of javaw.exe start consuming 100% of the cpu, or nearly so, after a bit. Sometimes it is immediately on loading a world. It doesn't happen when I'm playing on a server, or doesn't seem to be as bad.
Sometimes one of the javaw.exe processes keeps going and sucking cpu cycles after I quit minecraft and I have to end the process. I've read everything I could find on this, but no one seems to have any real solutions. I do have both 32-bit and 64-bit java installed, but Chrome needs 32-bit and Minecraft works better with 64-bit. Supposedly.
This does seem to be a 1.7 issue, as it never happened before the update.
Does anyone have any solution to this? It makes Minecraft basically unplayable after a few minutes.
Are you sure minecraft is using the 64 bit java? You could check in the developer console,
System.getProperty('os.arch') == 'x86'
...means it's using 32 bit,
System.getProperty('os.arch') == 'amd64'
,,,means it's using 64 bit.
Make sure your java is up-to-date, and make sure minecraft is using the 64 bit - you can force it to by editing your profile in the launcher, and under "Java", "Executable", put the path - probably "C:\Program Files\Java\jre7\bin\javaw.exe"
Also make sure you have the latest graphics card driver from your manufacturer - if you just upgraded windows, you might have a 'compatible' older driver.
Minecraft is using 64-bit Java - the line reads amd64 in the console.
The upgrade to Windows 7 was from XP, so not really an "upgrade" technically a clean install. Thus, Java is up to date (as of last week) and my graphics driver is up to date (double checked yesterday).
It would be of much benefit if you told us what processor you have. If you don't know how to you can check by a variety of means.
Right click "Computer" and click "Properties", you will then see your CPU listed.
Press the "Windows Key" and "R", type "dxdiag" and click "enter". You will see your CPU listed.
My desktop: Core2 Duo E7400 2.8GHz with 8 gigs of ram, and a NVidia GeForce 9600 GSO 512 graphics card on an EVGA nforce 750i sli motherboard. I built this in 2009.
Laptop is a Lenovo X220 with a core i5 @ 2.3 GHz with 4 gigs of ram.
Both have 64-bit Windows 7, and both have 64- and 32-bit versions of Java installed because of Chrome (wish Google would add support for 64-bit Java in Chrome).
Thanks for the replies and for any help you can give me!
1.7 is still quite "in development" - if you edit your profile to use the latest snapshot, you get (pre-release) version 1.7.3 which has quite a lot of bug-fixes, one of which may help?
Ok, tried that. It didn't seem to help anything though - same thing still happened.
I also tried setting the affinity of javaw.exe to just cpu0, which seemed to help for a while, but eventually I got a second javaw.exe running and together they started consuming near 100% of cpu again. They both terminated when I quit minecraft though.
I suggest you edit your profile and make sure it's on 64 bit java, and give minecraft a bit more memory; you have enough, and the latest versions of mc use more than the previous ones. And java can start using lots of CPU when it is low on RAM.
So in the launcher, edit profile, and under 'Java Settings' check the checkbox 'Executable' and put in the path to your 64-bit java, which is probably "C:\Program Files\Java\jre7\bin\javaw.exe" (without quotes). Then check "JVM arguments, and put "-Xmx2G -Xms1G" (without quotes).
Next thing I'd try is, remove any/all versions of java and reinstall them - I know, it's a pain, but that's what I'd do myself. I'd download the 'offline' versions from the java website, and install 32 bit then 64 bit.
If it still had trouble, I'd remove all of minecraft (after backing up any save games), and reinstall that too.
I hope you get some progress with it, good luck.
Thanks.
The path for java was that when I checked the box.
I already have 4 gigs allocated for minecraft. I added -Xms1G for the minimum.
I can try removing everything and reinstalling, though I did *just* install everything last Thursday when I got Windows 7 running. I did the offline versions for both javas, though I believe I may have installed 64-bit first.
I was running 1.7.2 on XP before I "upgraded" to Win7, and I was usually getting 100+ fps, now I'm getting less than 50 most of the time. I wonder if it has anything to do with running on Windows 7. Maybe I should try Ubuntu? Not sure if there are drivers for my hardware though... I suppose I could dual boot 7 and XP, except that I don't have a 64-bit version of XP, which is why I got 7 in the first place.
I guess I'll try just removing everything and redoing it... really don't know if that's going to be the solution though.
Ok tried that. I just went ahead and uninstalled both versions of Java as well as Minecraft, and then installed 32-bit, 64-bit, and then Minecraft.
I set the executable location as well as the JVM args again, to what I said in the last post.
I tested Minecraft for a few minutes. It seems to be so-so at first, only getting around 50 fps, but after a few minutes, I saw the second javaw.exe process come up, my fps went below 20, and again between the two processes they were using nearly 100% of cpu. Also, the 64 bit one is using 1.2 gigs of RAM, and the 32-bit one is using 196K - I guess the one is using over a gig because I set that to the minimum, though.
Again it was working perfectly fine in XP...not sure why it should be so problematic in Win 7.
Got anything else running? I wonder if it's actually a browser or something that is causing it.
BTW over 1Gb for minecraft isn't unusual, in 1.7.
There's no reason you'd have to change to Ubuntu, after all, there must be millions of people (including me) that are running it on Win 7 without any problems.
Oh, just one other thing;
Create a minecraft launcher profile that has "Enable experimental development versions ("snapshots")
Reason being, 1.7.3 is in pre-release and has a lot of bug-fixes.
Nothing else running, but I used to be able to watch youtube videos while running minecraft no problem.
Tried the prerelease already (posts 5-7 in this thread) - it didn't seem to change anything.
So I guess I just have to live with this till I get a better computer in a year or two? Kinda sucks...
I've recently started having this problem on both my Windows7 laptop and my newly-upgraded-to-Windows7 desktop. One or two instances of javaw.exe start consuming 100% of the cpu, or nearly so, after a bit. Sometimes it is immediately on loading a world. It doesn't happen when I'm playing on a server, or doesn't seem to be as bad.
Sometimes one of the javaw.exe processes keeps going and sucking cpu cycles after I quit minecraft and I have to end the process. I've read everything I could find on this, but no one seems to have any real solutions. I do have both 32-bit and 64-bit java installed, but Chrome needs 32-bit and Minecraft works better with 64-bit. Supposedly.
This does seem to be a 1.7 issue, as it never happened before the update.
Does anyone have any solution to this? It makes Minecraft basically unplayable after a few minutes.
Thanks!
- Jonathan
Minecraft is using 64-bit Java - the line reads amd64 in the console.
The upgrade to Windows 7 was from XP, so not really an "upgrade" technically a clean install. Thus, Java is up to date (as of last week) and my graphics driver is up to date (double checked yesterday).
My desktop: Core2 Duo E7400 2.8GHz with 8 gigs of ram, and a NVidia GeForce 9600 GSO 512 graphics card on an EVGA nforce 750i sli motherboard. I built this in 2009.
Laptop is a Lenovo X220 with a core i5 @ 2.3 GHz with 4 gigs of ram.
Both have 64-bit Windows 7, and both have 64- and 32-bit versions of Java installed because of Chrome (wish Google would add support for 64-bit Java in Chrome).
Thanks for the replies and for any help you can give me!
Hmm I'll try that, thanks.
I also tried setting the affinity of javaw.exe to just cpu0, which seemed to help for a while, but eventually I got a second javaw.exe running and together they started consuming near 100% of cpu again. They both terminated when I quit minecraft though.
Thanks.
The path for java was that when I checked the box.
I already have 4 gigs allocated for minecraft. I added -Xms1G for the minimum.
I can try removing everything and reinstalling, though I did *just* install everything last Thursday when I got Windows 7 running. I did the offline versions for both javas, though I believe I may have installed 64-bit first.
I was running 1.7.2 on XP before I "upgraded" to Win7, and I was usually getting 100+ fps, now I'm getting less than 50 most of the time. I wonder if it has anything to do with running on Windows 7. Maybe I should try Ubuntu? Not sure if there are drivers for my hardware though... I suppose I could dual boot 7 and XP, except that I don't have a 64-bit version of XP, which is why I got 7 in the first place.
I guess I'll try just removing everything and redoing it... really don't know if that's going to be the solution though.
Thanks for your help so far!
I set the executable location as well as the JVM args again, to what I said in the last post.
I tested Minecraft for a few minutes. It seems to be so-so at first, only getting around 50 fps, but after a few minutes, I saw the second javaw.exe process come up, my fps went below 20, and again between the two processes they were using nearly 100% of cpu. Also, the 64 bit one is using 1.2 gigs of RAM, and the 32-bit one is using 196K - I guess the one is using over a gig because I set that to the minimum, though.
Again it was working perfectly fine in XP...not sure why it should be so problematic in Win 7.
Nothing else running, but I used to be able to watch youtube videos while running minecraft no problem.
Tried the prerelease already (posts 5-7 in this thread) - it didn't seem to change anything.
So I guess I just have to live with this till I get a better computer in a year or two? Kinda sucks...
Thanks for all your help though.
Thanks again for all your help!
- Johonn