The Reasons Behind 754, 939 and 940 pins

[Omega65]

The Inq: <a href="http://www.theinquirer.net/?article=11789" target=_blank><b>Athlon 64 sockets explained</b></a>

<i>
At the technical symposium following the Athlon 64 launch, Mike Goddard, AMD Director of Technical Marketing of the firm's Computation Products Group, explained it in a way that it has left almost as many questions unanswered. But the long and the short of it is that <b>Socket 940 requires a 6 to 9 layer motherboard and Socket 939 only requires a 4 layer design</b>, making the motherboards much cheaper for chips using the latter.

Goddard is a seriously technical guy, he comes from a background of designing chips himself and knows a thing or two. He said that Socket 939 would allow later Athlon FX chips to use standard DDR memory rather than the current requirement for ECC registered DDR.
</i>

<a href="http://www.theinquirer.net/?article=11789" target=_blank>read the rest here</a>

[kanezfan]

but isn't the FX basically an Opteron anyway? that doesn't make sense. well at least the memory won't be a problem anymore.

[Omega65]

Opteron Motherboards (940pin - 6-9 layer design) are $150-$250 and can only use Registered ECC DDR (Registered DDR 400 ~$200 per 512MB) x 2 (Dual Channel)

Athlon FX (939pin - 4 layer design motherboards) will use regular Unbuffered DDR333/400 (~$75 / 512MB stick)

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Although IMO it seems strange that One pin can make that much of a difference. I think AMD is trying to stratify it's CPU market into High, Mid and Low end via Motherboard sockets. They're ignoring the fact that one of the reasons thry're popular among enthusiasts is that one Socket 462 was good for all the Athlons and Durons.

They should drop Socket 754 and 939 just use Socket 940

[SimGuy]

But another selling point of AMD Athlon processors has always been that they are cheap. Are users going to pay extra because of the neccessity of Registered (Buffered) DDR SDRAM (ie 250% more than Unregistered) and the extra price for a 6-9 layer motherboard over a 4-layer designed one?

Powerful or not, if it's extremely expensive, enthusiasts and regular users won't go for it.

IMHO, they should keep 940 for the Opteron's and keep 939 for the Athlon 64 FX & Athlon 64. Even though the Athlon 64 only needs 754 pins, they could use the others for nothing or extra ground lines.

[Mt_Goat]

SimGuy

Nicely put!

[gtghm]

Looks like AMD is treading on shakey ground...
It appears that they are betting that people will not care how much it costs to go to 64bit...

I wonder... will the AMD faithful step up and pay the price for the 64... Can you allow your self to by the low end CPU knowing that you can't ever upgrade to the higher tear CPUs they might offer...?

It will be interesting to see how it all plays out...

"g"

[WuGgaRoO]

hmmm...seems amd is getting a bit expensive...will the fx version have the ability to run a dual cpu..or is that opteron only

[kanezfan]

different pinouts wug, opterons will be the only ones to run in dual mode, unless someone invents a dual FX board, and some way to run FXs in dual mode..... er yeah, that's the ticket

[Thrax]

The 940 FX-51s appear to be SMP-compatible. The only difference between it and the Opteron seems to be the addition of DDR400 support on the IMC for the FX-51.

[a2jfreak]

You won't be able to run the FX chips in dual configuration because of the number of working HT links. Only way to get it to work would be to have an FX chip with more working HT links than AMD claims the FX to have or to give up having hard drives, etc. There might be a way (meaning possible, although very improbable) to have two FX chips share 1 HD, 1 NIC and still talk to each other via an arbiter chip though would double as a southbridge, but I don't know for sure.

[WuGgaRoO]

grrrr.... ohwell....cant have everything u want i suppose