Athlon 64 3400 & Athlon 64 FX

[shadow of chaos]

Just wondering, but what is the difference between the 2? i know the price difference between the 3000 64 up to 3400 is very steep and you can probably get the 3000 past 3400 speed anyway by overclocking, but there is a very big leap in price by the 64 FX.. whats that all about?? higher cache or something? or is it like the Athlon MP for dual cpu motherboards?

[Tin]

the A64 3400+ has an 800MHz hypertransport bus, which is pretty much the FSB. A64 3400+ is only capable of single channel memory access, hence the 800MHz hypertransport. the FX on the other hand, is dual channel capable, so its hypertransport bus is 1600MHz....so in basic terms, the FX has twice the FSB of the socket 754 variation. current socket 940 is single channel, so the hypertransport bus gets scaled back to 800MHzbut. socket 940 also uses only ECC DDR. socket 939 will be out in march, and it will be dual channel capable, and will not support ECC DDR, since its missing 1 pin. the athlon XP, in the meantime, will change over to socket 754 later this year, but will still operate on the 333/400FSB architecture of socket 462. the socket 754 AMD64 CPUs will be replaced by socket 939, and socket 940 will be an opteron only configuration. The current line of opteron/FX chips are crippled as of now, because nforce250 hasnt been released yet. nforce250 is the dual channel version of the nforce150, so in essence, youll get to use your full 1600MHz hypertransport bus and be showing off some downright evil benchmarks. if you think the FX kills the P4C now, wait until nforce250 hits and it gets twice the bandwidth.

[lukejd87]

Originally posted by Tin Canary
the A64 3400+ has an 800MHz hypertransport bus, which is pretty much the FSB. A64 3400+ is only capable of single channel memory access, hence the 800MHz hypertransport. the FX on the other hand, is dual channel capable, so its hypertransport bus is 1600MHz....so in basic terms, the FX has twice the FSB of the socket 754 variation. current socket 940 is single channel, so the hypertransport bus gets scaled back to 800MHzbut. socket 940 also uses only ECC DDR. socket 939 will be out in march, and it will be dual channel capable, and will not support ECC DDR, since its missing 1 pin. the athlon XP, in the meantime, will change over to socket 754 later this year, but will still operate on the 333/400FSB architecture of socket 462. the socket 754 AMD64 CPUs will be replaced by socket 939, and socket 940 will be an opteron only configuration. The current line of opteron/FX chips are crippled as of now, because nforce250 hasnt been released yet. nforce250 is the dual channel version of the nforce150, so in essence, youll get to use your full 1600MHz hypertransport bus and be showing off some downright evil benchmarks. if you think the FX kills the P4C now, wait until nforce250 hits and it gets twice the bandwidth.

I'm not sure how old this is but I wanted to make some correction that Tin Canary accidently missunderstood.

The FX does not have twice the FSB. They both have a 1600Mhz bus (800Mhz DDR [1600Mhz effective]) The FX just has a dual channel memory controller, which means that it gets twice the memory bandwidth. And the current nForce3 150 DOES have dual channel. 250 just stands for the second revision of the 150, like all the bugs are worked out.

Secondly, the 754 isn't going to be removed anytime soon, yes there will be Athlon64 for the 939 and athlonXp fo rthe 754, but both sockets are staying.

The FX and Opteron are not crippled they are at their opening performance. I don't see them getting too faster with a different motherboard.

In summary the only difference is that the Athlon64 has a single channel memory controller, and the FX has a dual channel. That's it.