Confused on new Memory and Processors

[gwtx2]

I have a good grip on understanding the Athlon XP series bus speeds and
compatible memory; however, I 'm somewhat stumped on the new Athlon 64
X2 (AM2 socket) chips and what is the "fastest" DDR2 memory they will
work with (fully take advantage of).

For example, the tour tab on the following Newegg link
(http://www.newegg.com/Product/Product.asp?Item=N82E16819103735)

mentions that the
AMD Athlon 64 X2 3800+ Windsor 2.0GHz 2 x 512KB L2 Cache Socket AM2
Processor

will support up to DDR2 400 memory.

This link
http://www.newegg.com/Product/Product.asp?Item=N82E16819103751

mentions that the
AMD Athlon 64 X2 4600+ Windsor 2.4GHz 2 x 512KB L2 Cache Socket AM2
Processor

will support up to DDR2 800 memory.

I realize the DDR2 800 memory can be used with a processor that only
supports up to DDR2 400 and that the speed will drop to the DDR2 400
spec.

My question is what is the X2 AM2 specification which denotes the
highest DDR2 memory speed which can be utilized? With the old Athlon XP
chips, the FSB spec was commonly used to pair with the correct memory.

 

[Wes Newell]

My question is what is the X2 AM2 specification which denotes the
highest DDR2 memory speed which can be utilized? With the old Athlon XP
chips, the FSB spec was commonly used to pair with the correct memory.

It supports the same bus speed as the XP line did, 200MHz. However that
200MHz using ddr2 has twice the bandwidth, so it's DDR2-800 where it was
is DDR-400. Of course like XP, it can be overclocked to whatever you can
get the controller to support. Confusion is what you end up with when they
erroneously use data rates as MHz. Unfortunately even ram manufactures
which used to list the real bus speeds of the ram have now started
advertising the data rates as the bus speed. It's gottten so bad now that
if you aren't familar with what they do, you'll be screwed trying to
design a system. I wonder what will happen in the distant future when some
one tries to actually build a board for one of todays cpu's and really
puts the clock speed at what they advertise today. Can you say meltdown.

 

[eddy]

It supports the same bus speed as the XP line did, 200MHz. However that
200MHz using ddr2 has twice the bandwidth, so it's DDR2-800 where it was
is DDR-400. Of course like XP, it can be overclocked to whatever you can
get the controller to support. Confusion is what you end up with when they
erroneously use data rates as MHz. Unfortunately even ram manufactures
which used to list the real bus speeds of the ram have now started
advertising the data rates as the bus speed. It's gottten so bad now that
if you aren't familar with what they do, you'll be screwed trying to
design a system. I wonder what will happen in the distant future when some
one tries to actually build a board for one of todays cpu's and really
puts the clock speed at what they advertise today. Can you say meltdown.

I found the buzz on am2 and ddr2 needlessly muddled also. I think
they just want to confuse customers so they'll buy low performance
at premium prices with more margin for the dealers.

I wouldn't bother with am2/ddr2. I'd go with socket 939 in AMD or
core2duo if I want Intel.

AM2 looks like a loser and the 65nm parts look even worse.

 

[General Schvantzkoph]

I found the buzz on am2 and ddr2 needlessly muddled also. I think
they just want to confuse customers so they'll buy low performance
at premium prices with more margin for the dealers.

I wouldn't bother with am2/ddr2. I'd go with socket 939 in AMD or
core2duo if I want Intel.

AM2 looks like a loser and the 65nm parts look even worse.

If you buy a new AMD system you absolutely do not want socket 939. AMD has
stopped production of socket 939 parts, they have switched entirely to
socket AM2. Also there will never be 2G DDR DIMMs so the maximum memory
size of a socket 939 pin system is only 4G. There are 2G DDR2 DIMMs, I'm
using the GSkill 2G DIMMs in my Core2 system, so an 8G AM2 or Core2 system
is possible.

There is no question that Core2 systems are faster than Athlon 64 X2
systems. However the Nforce A64 motherboards give you more for your money
then the 965 Core2 motherboards, 2 Ethernet MACs vs 1, and 100% Linux
compatibility out of the box. The Core2 systems still require some
fiddling to run well under Linux. So if you aren't looking for the fastest
possible system there is still a reason to consider an AM2 A64 system. The
Core2s are about 30% faster then an X2 on a clock for clock basis so if
you you could get a 2.6GHz X2 system for the same price as a 2GHz Core2
system you'll be getting the same performance for your money.