939 or 940

Socket 939 would be a better bet. 940 limits you to opeterons and some of the FX chips, plus all the socket 940 motherboards will need expensive Registered memory (as they're basically Server boards)

You simply get a bit more flexibility with your choices if you go for 939 (or even 754)

Opteron and <i>clawhammer</i> core A64 are basically the same chip. 'Newcastle' has less cache, but it's not that big an issue with A64 chips because the on-die memory controller makes memory access much faster.

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Epox 8RDA+ V1.1 w/ Custom NB HS
XP1700+ @200x10 (~2Ghz), 1.4 Vcore
2x256Mb Corsair PC3200LL/1x512Mb Corsair XMS PC4000 2.5-3-3-7
Sapphire 9800Pro (VGA Silencer Rev3) @418/742

Screw 940 when 754 is about the same and is much cheaper.

If you really dont care about that extra cache then go for 939. Plus you dont have to get the slow registered ram like from 940 and 754.

Mobile Barton 2500+ @ 2420mhz 11x220 1.7v
Asus A7N8X Dlx 440 FSB
1gb Geil GD pc3500 Dual Channel (2-3-3-6)
Segata 80gb SATA 8.5ms seek
ATI Radeon 9800 Pro to XT(463/795)

You don't need registered ram for 754. The main draw to 939 is the dual channel memory.

754: Non-registered ram (Mainstream)
939: Dual channel non-registered ram (High end)
940: Registered ram (server)

AMD 64 3400+
MSI K8N Neo Platinum
1 GB Kingston HyperX PC3200
ATI AIW 9600XT
WD Raptor 74GB

The thing is, by the time you need to upgrade from a 3700+, you are going to need a new mobo anyway for pciexpress and etc.

Watch out for the <b><font color=red>bloody</font color=red></b> Fanboys!

AMD64 2800+ :: MSI Neo-Fis2r :: 512mb Kingmax ddr400 :: Sapphire 9800pro 128mb :: 10K WD Raptor

Addicted, finally.