Minecraft Random Lag Spikes? - 1

I've had minecraft for a while and recently when i try and run a game it starts to bring on random lagspikes, and i have optifine, but this comes with every single server i'm on so its not server lag, and i have about a 54 ping, so is there anything you can recommend for me to get me back into the 60+ fps i used to get on my desktop. I don't have too much of a good desktop at the moment but it used to run fine, heres my specifications:
Operating System
Windows 7 Ultimate 64-bit SP1
CPU
Intel Core 2 Duo E4300 @ 1.80GHz69
Conroe 65nm Technology
RAM
8.00GB Dual-Channel DDR2 @ 333MHz (5-5-5-15)
Motherboard
Hewlett-Packard 0A68h (XU1 PROCESSOR)72
Graphics
HP x20LED (1600x900@60Hz)
256MB NVIDIA Quadro FX 380 (NVIDIA)47
Storage
931GB Seagate ST1000DM003-1ER162 ATA Device (SATA)30
Optical Drives
HL-DT-ST RW/DVD GCC-4482B ATA Device
Audio
High Definition Audio Device

I have seen this problem before, seems like a problem with the RAM Minecraft is aloud to use.
Try these steps:

Open up your Minecraft launcher, but don't log in.

Click the Edit Profile. Button on the bottom left of your screen.

In this new menu click the JVM Arguments box.

In the text box to the right of this menu you will notice a box that will say something like "-Xmx1G" by default.
This "1G" represents 1G of RAM allocated to Minecraft and can be changed to increase the amount.