Questions re building a dual AMD cpu machine

[Zim]

I need to put together a very fast PC for some serious number crunching. At the moment I'm considering a dual AMD cpu machine, with either AMD 64's or Opterons (1MB L2 cache). I assume these will give more bang for the buck than Intel's offerings. The case must be rackmount because we are running out of room for anything else. I will need about 2 - 4GB of RAM. Can any of you guys give me advice on:

- What's the difference between AMD 64's and Opteron's?
- What's the difference between socket 939 and 940?
- Are there any good motherboards out there that can handle dual AMD's?
- What is the benefits of ECC Registered memory over standard memory?
- What's the speed difference between ECC Registered memory and normal memory?

Thanks!

 

[Demo24]

I dont think you can do dual 939s so opterons are your only choice

 

[w0ss]

Also remember since the opteron memory controller is on the chip you are forced to use registered ram. I think AMD is still the faster/cheaper solution but it's fairly close. If you can get in on a hot deal then that could sway it one way or the other.

 

[ts3433]

Athlon 64 takes unregistered RAM; Opteron requires registered, as well as the older FX-51 and FX-53 (this is also the main difference between the 754/939 sockets and socket 940).
ECC/Registered has to do with error checking and provides for server-grade stability; this stuff is a little slower than unbuffered RAM.

 

[Zim]

Thanks guys. What's the difference between the 1xx and 2xx Opterons?

 

[Markfw]

You have to have 2xx opterons to run dual. And registered is not that much more exspensive. Just pick a budget and then pick your cpu's and motherboard. My Tyans Thunder is exspensive since it has 64 bit PCI-X slots which I need for my SCSI controller to breathe....($429 just for the mobo)

 

[Zim]

Thanks. OK, here's my spec so far:

2 x Retail Opteron 244 ($660)

http://www.tomshardware.com/cp...030422/opteron-19.html

1 x Tyan K8W Tiger S2875 motherboard ($237)

http://www.gamepc.com/labs/vie...id=tigerk8w&page=1

1 x ATX Rackmount Case w/PSU ($180)
2 x PQI 1GB PC3200 ECC Registered ($400).
1 x 74GB WD Raptor ($177)
DVDROM, Video Card, etc. ($100)

*** TOTAL: ~$1800

 

[Markfw]

get 4x512, otherwise you loose dual channel. 2 for each cpu. and they wont run at better than 333 (PC2700) unless you get 246 or better cpu's.

 

[Zim]

Originally posted by: Markfw900
get 4x512, otherwise you loose dual channel. 2 for each cpu. and they wont run at better than 333 (PC2700) unless you get 246 or better cpu's.

Thanks, I saw another mention of that elsewhere but now you've confirmed it. I reckon I should go up to the 246's then and get 4GB of memory. That'll add another $700 to the ticket.