Runs OK on 32bit; barely runs at all with 64bit?

[smotchel]

Basically, when I try and run an FTB pack with 32bit Java and the limited 1.5gb RAM it is playable, but not ideal. When I upgraded to 64bit Java and put my RAM up to 4gb (out of 8) it barely runs at all. This doesn't make any sense to me, so here I am, I'm not the greatest with computers so if someone could help me that would be much appreciated.

 

[gold49]

Do you have any other programs that could be using ram?
Also see what happens when you bring the ram down to three gigs and two gigs with 64 bit. There is such a thing as too much ram in some packs.

 

[Hambeau]

I'm assuming you have a 64 bit OS.
Also, you need at least 6GB ram* installed in the system if you want to allocate 4GB to MC, unless you enjoy beating the snot out of your hard drive writing to your OS's swap area constantly... The OS has to keep running, after all.

* 6GB is easier to install than 5 or 5.5 GB, usually.

 

[Cptqrk]

Since you are still using 34bit Java I'm going to assume you are not playing 1.7 packs, as almost all require 64bit Java.

2gigs of ram is the sweet spot on older packs with 32bit Java, as it doesn't get hung up on massive garbage collection


Sent from my iPhone using Tapatalk

 

[rhn]

Basically, when I try and run an FTB pack with 32bit Java and the limited 1.5gb RAM it is playable, but not ideal. When I upgraded to 64bit Java and put my RAM up to 4gb (out of 8) it barely runs at all. This doesn't make any sense to me, so here I am, I'm not the greatest with computers so if someone could help me that would be much appreciated.

If the pack runs with 1.5GB ram, WHY WHY WHY do you allocate 4GB to it??? RAM is not a go faster button. If the RAM allocated is large enough to hold the files needed, then more is completely unnecessary.

By allocating 4GB out of 8GB you can very likely be maxing out your RAM and end up using the Pagefile(your harddrive) extensively. JAVA often use much more "behind the scenes" than what you allocate in the launcher(I have personally seen it use +50-70%). And remember that you still need enough for OS, browser, background services etc.

Load your pack/world, Press F3 and check the upper right corner. It will show you exactly how much memory the game is using there. Allocate slightly more than that and you are good.

 

[b0bst3r]

Did you change the options - java path in the ftb launcher to use 64bit java?