Re: 512MB PC3200 or 1GB PC2700
You will notice a bigger improvement with the more memory but slower frequency.
Although I know you keep your processor overclocked and I dont know how many options for memory dividers your motherboard has. So you might not be able to keep your overclock because of the memory.
The Amish computer:
AMD Opteron 165 CCBWE 0551@ 2.25ghz(250 x 9) 1.45v cooled w/ Thermaltake Big Typhoon | DFI LP Ultra D | eVGA 7800GT@ 465/1110 | Sound Blaster X-Fi XtremeMusic | 2GB G. Skill DDR 500 @ 250mhz 3-4-4-8 | 80 GB SATA + 40GB SATA + 200GB IDE| 480w Thermaltake Silent purepower | Thermaltake Tsunami Dream case (Black) | Windows XP Pro |