Now, AMD is stirring things up again by introducing a new model of Athlon 64, the 3400+. Running at 2.2GHz, this CPU is very similar to the Athlon 64 FX-51, except that the 3400+ slides into a 754-pin socket and talks to only one channel of DDR400 memory. So the 3400+ doesn't break new ground in terms of clock frequencies, but its introduction does suggest AMD is comfortable in its ability to produce enough 2.2GHz Athlon 64 processors to bring this speed grade to its higher-volume desktop platform.
We're interested to learn several things about the 3400+. Its performance rating, for instance, suggests it's faster than a theoretical Pentium 4 3.4GHz CPU. Can its performance back up that (implicit) claim? Also, how much difference is there between one memory channel and two? We've tested the Athlon 64 3400+ against its companions and competitors in an attempt to answer these questions, so read on.
In this corner...
Those of you not familiar with the Athlon 64 will want to read our initial review of the processor before continuing here. To refresh your memory, though, the Athlon 64 3400+ has a number of notable assets that help separate it from its predecessor, the Athlon XP. Among its virtues: an on-chip memory controller to cut memory access latency, a hefty 1MB of level 2 cache, support for SSE2 instructions, a radical system infrastructure based on high-speed HyperTransport links, and AMD's 64-bit instruction set extensions. These changes have made the Athlon 64 a very tough competitor for the Pentium 4, even though Microsoft hasn't yet delivered a 64-bit version of Windows.
Of course, we'd be remiss not to present some pictures of the Athlon 64 3400+. This particular chip, unlike our previous Athlon 64 and Opteron review units, sits on packaging dyed green, making it look very similar to a Pentium 4.
So that's our subject today. Not much to look at, but what did you expect?
Interestingly enough, our A64 3400+ review unit showed us a less-than-cosmetic difference between itself and our A64 3200+ processor: the ability to run at CAS 2 with our Corsair test memory. Normally, we'd try to chalk up this difference to the chipset or some other external factor, but in this case, the memory controller is on the chip. AMD has no doubt made some revisions to the A64 over time, and it seems very possible the memory controller has been tweaked a bit. Whatever the case, our test results for the Athlon 64 3400+ use CAS 2 memory timings, and the 3400+ was entirely stable at CAS 2. Our A64 3200+ chip, however, was not, and we had to test it at CAS 2.5.
The other guys
The 3400+ is the star of the show today, but there are a couple of other Athlon 64 processors worth mentioning. For one thing, our benchmark results reflect a change in the Athlon 64 FX-51 system config. Corsair and other top memory makers have now produced low-latency memory for the Athlon 64 FX, registered DDR400 memory capable of running at a CAS latency of 2, so we've retested the FX with some. As a result, most of our Athlon 64 FX-51 scores are a little better than they were last time around, when we were running at CAS 2.5. That's a noteworthy development, because the Athlon 64 FX-51 was already the fastest processor around.
On the other end of the spectrum, AMD recently introduced, very quietly, a relatively inexpensive version of the Athlon 64, the 3000+. This CPU is very similar to other Athlon 64 chips, except that it has only 512K of L2 cache on board, not the 1MB you'll find in most Athlon 64 chips, and it runs at 2.0GHz. Most importantly, this puppy lists at only $218, or under a third what you'd pay for an Athlon 64 FX-51. That's a heckuva price for a 2GHz "Hammer" processor, even with a smaller L2 cache.
Intrigued, we ordered up an Athlon 64 3000+ for testing from an online vendor, but the bums didn't get it here in time for our article. We will have to update you on the A64 3000+'s performance numbers at a later date.
Now, on with the show...