is launching their second Athlon64 (A64) CPU today. This 3400+
is running at 2.20GHz and comes on a 1600MHz (1.60GHz) Hypertransport
connection between the memory and CPU or a 2.20GHz connection
between the memory controller (integrated) and CPU. You might
recall we reviewed the FX-51 just a few months ago and found
its performance to be spectacular. The 3XXX+ series
have now become AMDs "mainstream" part and
thus should not be considered in the same class as the FX-51.
Intel should be countering the 3XXX series with their upcoming
Prescott CPU core but we have yet to see Prescott make its
introduction. We believed that we might see Prescott about
when the FX-51 came to market, but Intel has been rumored
to be having heat issues with Prescott and has delayed its
launch to sometime later this quarter. In the meantime, AMD
is running right along with their A64 core and seeing wonderful
results. Rumor on the AMD side is that we might be seeing
a newer FX chip sometime soon. Im sure its only
a matter of time.
AMD Athlon 64 3400+
Some of you might be wondering what
the differences are between the Athlon64 3XXX series (like
our 3400+) and the FX series (like the FX-51). The main architecture
differences revolve around the integrated memory controller.
The FX-51 uses a 128-bit wide bus to transfer data while our
Athlon64 3400+ uses a 64-bit interface. Essentially the FX-51
has twice the memory bandwidth from information being sent
to and from the integrated memory controller interface.
AMD Athlon Processors
(click on the image for an enlarged version)
As you can see in the chart above,
there are few other differences between the FX-51 and A64.
The biggest physical difference is a major issue if your looking
for a new machine, The FX-51 and A64 use different socket
sizes. They are not pin compatible. Both CPUs take
advantage of 1MB of L2 cache. They share the same die size
and both support the same 3D instructions, including SSE2.
A new feature added to the 3XXX series
is what AMD calls Cool n Quiet. When
your desktop CPU is up and running, it runs at full speed
100% of the time. It does not matter if you're playing LOMAC
or typing a review in Microsoft Word, the CPU is always throttled
up to maximum. On mobile CPUs, the chips will scale up and
down as per use. If youre watching a DVD or typing in
Microsoft Word, the CPU might only be running at 50% utilization.
If you switch off the DVD and start a game, the CPU recognizes
(instantaneously) that there are more demands being made and
it throttles up to 100%.
AMD has taken those same features
and implemented them on a desktop CPU. When your CPU needs
to be at full speed, it will operate at (in this case) 2.20GHz.
If your typing in Microsoft Word and your CPU has decided
to throttle down (say to 1GHz) two things happen.
Youre not producing as much
heat. Your system runs cooler and keeps lockups from occurring.
Now your fan will also slow down to create less noise because
less heat is being generated from a CPU that is operating
at a lower CPU speed.
This is all good unless the CPU is
deciding to throttle down on its own for other reasons.
We will have to get with AMD and find out exactly what point
the CPU determines that its "all clear" to
throttle down. We certainly would not want the CPU to throttle
down suddenly in the middle of a LOMAC mission!
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