How Much DDR3 memory do I really Need?

[Hefemeister]

asus p6t and asus 5870
Newegg.com - Computer Parts, PC Components, Laptop Computers, Digital Cameras and more! $614

i7 920 and ocz gold 6gb
Newegg.com - Computer Parts, PC Components, Laptop Computers, Digital Cameras and more! $426 w/ $20 mir

Newegg.com - COOLER MASTER HAF 932 RC-932-KKN1-GP Black Steel ATX Full Tower Computer Case - Computer Cases $140

Newegg.com - CORSAIR CMPSU-650TX 650W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 Power Supply - Power Supplies $89 w/ $10 mir

Newegg.com - LG Black 22X DVD+R 8X DVD+RW 22X DVD-R 16X DVD-ROM 48X CD-ROM 2MB Cache SATA DVD Burner - CD / DVD Burners $28

Newegg.com - Western Digital Caviar Black WD6401AALS 640GB 7200 RPM 32MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive $75

Newegg.com - Microsoft Windows 7 Home Premium 64-bit 1-Pack for System Builders - Operating Systems $105

Newegg.com - SAMSUNG ToC T240HD Rose-Black 24" 5ms HDMI Widescreen HDTV Monitor 300 cd/m2 DC 10000:1 Built in DTV Tuner & Dolby Digital Surround Speakers - LCD Monitors $249


$1726 with $30 in mir and some shipping costs. That does include a 24" 1920x1200 monitor as well. Would need keyboard and mouse if you do not have and if you wanted to overclock much you would need to spend $40ish on a heatsink.

I5 / PII will come out cheaper but this is about as good as it gets right now.

 

[VishKapish]

You could save a little (after rebate) if you go with:
Newegg.com - OCZ StealthXStream OCZ700SXS 700W ATX12V / EPS12V SLI Ready CrossFire Ready Active PFC Power Supply - Power Supplies

Or, since the 5870 requires around 500W of power,

Newegg.com - OCZ Fatal1ty OCZ550FTY 550W ATX12V / EPS12V SLI Ready CrossFire Ready Modular Active PFC Power Supply - Power Supplies

 

[stuperprohero]

I guess I forgot to mention this will be a tax time build so most of these mir's will be outdated by then.
I'm wondering if I couldn't save some cash by going with an i5. Looking at newegg reviews on the i5 they say hyperthreading isn't important for gaming. It's the memory slots and PCI slots I'm concerned about for an i5 build.

I also forgot to mention I want to run flight simulators on max too.

 

[S0ULphIRE]

Some of the i5 series are really good, however they won't support triple channel memory or HT. If price is an issue for you (and I'm talking somewhere in the region of 70-90 bucks difference JUST for the cpu) then go with the i5. The overall system cost is much lower than an i7 system.

Depends on your personal preference, which is more important? cost or performance?