My 1st pc is Pentium D 820 which is Dual Core . It has 512 KB DDR Ram (PC3200) & speed of CPU is 200Mhz x 14= 2.8 GHz . When I ran Everest Ultimate Edition on my P.C. , it gives the following information : CPU Physical Info : Package Type = 775 Contact LGA Process Technology = 7M , 90 nm , CMOS , Cu , Low-K Inter-Layer , High-K Gate ,Strained Si Core Voltage = 1.3 V I/O Voltage = 1.3 V Typical Power = 95 W @ 2.8 GHz Maximum Power = 130 W @ 2.8 GHz MotherBoard Info : MotherBoard Name = MSI865GVM3-V ((MS-7101) FSB Properties: Bus Width = 64 bits Real Clock = 200 Mhz (QDR) Effective Clock = 800 Megahertz Bandwidth = 6400 MB/s Memory Bus Properties : Bus Width = 64 bits DRam:FSB Ratio = 1 Real Clock = 200 Mhz (DDR) Effective Clock = 400 Megahertz Bandwidth = 3200 MB/s Chipset Bus Properties : Bus Width = 8 bits Real Clock = 67 Mhz (QDR) Effective Clock = 267 Megahertz Bandwidth = 267 MB/s The 2nd P.C. is an AMD Athlon 64 X2 5200+ (Dual Core) . It has 2 GB of DDR2 Memory (PC26400) & speed of CPU is 200Mhz x 13.5 = 2.7 GHz . For the Second P.C. ,Details are as following : CPU PhysicalInfo : Package Type = 940 Pin uOPGA Process Technology = 10Mi , 65 nm CMOS , Cu , DSL SOI Core Voltage = 1.1 - 1.35 V I/O Voltage = 1.2 V - 2.5 V maximum Power = 65 - 76 Watts MotherBoardName = Asus M2N68-AM SE2 FSB Properties: Bus Type = AMD Hammer Real Clock = 200 Mhz Effective Clock = 200 Megahertz HyperTransport Clock = [Trial Version ] Memory Bus Properties : Bus Type = DDR2 SDRam Bus Width = 64 bits DRam:FSB Ratio = CPU/7 Real Clock = 387 Mhz (DDR) Effective Clock = 775 Megahertz Bandwidth = [Trial Version ] MotherBoard Physical Info : CPU Sockets/slots = 1 Socket AM2+ Expansion Slots = [Trial Version ] RAM Slots = 2 DDR2 RAM Integrated Devices = Audio , Video , Lan Form Factor = Micro ATX MotherBoard Chipset = nForce7025-630a MotherBoard Manufacturer = ASUSTek Computer Inc. 1) Are there any Bottlenecks (for speed , performance , etc ) on any of these P.C.s ? If there is any more info you need , I'd be happy to give . 2) What is the maximum physical memory that can be put on each of these p.c.s ? 3) Also , since both CPUs are x86-64 machines but since my windows is 32 bit (Windows XP Professional SP2) , aren't these machines being under-utilized ? (Although I can understand , 64-bit windows isn't very popular since getting drivers for programs can become a problem ) . 4) Upon running CPU-Z , Core Voltage shown on the Intel P.C. is 1.33 Volts as against 1.39 volts for the AMD machine . However RAM Voltage is 2.5 for Intel vs 1.8 for the AMD machine . Which machine must be consuming more power ? 5) Nero System Info says there is AWRDACPI on the machines . If ACPI is installed , why am I not given any option by Windows whereby I can make settings for Windows to automatically shut down the Printer if the Printer or Scanner is idle for say n number of minutes ?