Almost identical PC, different performance

[Drugoli]

Me and my older brother have a lot of the same components, including:

Same mother - Asus Sabertooth 990FX 2.0

Same CPU - FX 8350 (OC'ed to 4.4GHz)

Same GPU - Sapphire R9 290 Tri-X (stock)

We tried to play some Minecraft yesterday, he ran a server which I joined. Ping is very good, sub 30ms constantly. We're running with a lot of mods, 50+ I'm guessing without having counted (http://www.technicpack.net/modpack/details/ultra-modded-survival-pack.266012). We both use roughly the same graphical settings as well ingame. Also, lowering mine doesn't seem to help that much.

The weird thing/problem is, he's getting constant 70-80+ (sometimes 100+) FPS all the time, but I'm struggling to get even 60 sometimes. Why is this? I have no clue myself.

Other games seem to run fine. I can get almost constant 90 FPS (I've set this to be the limit) in Battlefield 4 with settings just shy of ultra. And Tomb Raider (new one) also runs with 60+FPS at maximum settings.

[Guest]

Update drivers, optifine, Java version

[_ASSASSIN_]

OC'd maybe? Also optifine can help in minecraft.

[The_Ginger_spoon]

are both of your displays at the same resolution?

 

[Guest Kloaked]

Did you enable v-sync?

[HiddenFox]

Mybe oh the hard drive is used more / fragmented datacould be a factor

[renz62]

It could be caused by outdated drivers, room temperature, OC and the likes

[Guest]

are both of your displays at the same resolution?

 

Please change your signature, It's making me accidentally scroll horizontally

[Drugoli]

To answer all of the questions:

• The modpack we use includes stuff like optifine and a few others like it.
• My display resolution is 1680x1050, his is above 1080p, not sure of the exact resolution.
• About the harddrive, Minecraft and everything is installed on my boot drive, Vertex 4 SSD, I believe his boot drive is the same. Though he has tons of drives, both SSD and HDD, so I'm not sure where his is installed.
• We both live in the same country, so room temperatures about roughly the same, 20-22C.
• I think at the time, he was running AMD drivers version 14.4 beta, and me 14.2
• About OC's, we both have the same exact settings for our CPU's (he helped me set up mine to his settings). And as far as I know, he hasn't OC'ed his GPU yet, which I haven't either. 

I've just updated Java, and I'll try and update GPU drivers to 14.4 WHQL, and try and run the game again.

[ManIkWeet]

There's actually a noticeable difference in Minecraft between using 64bit or 32bit Java.