AMD's Athlon XP 2100+ Processor
Crunching Code at 1733MHz.

By, Marco Chiappetta
March 13, 2002


The physical attributes of the Athlon XP certainly haven't changed much.  With the exception of the new green grid array packaging, physically there is nothing out of the ordinary to report about the Athlon XP 2100+.  If you're wondering why AMD is making the switch to green packaging, we've got the answer.  It has nothing to do with performance, but rather to make the CPU's color and appearance more closely match AMD's company logo.  So you can all stop speculating!  We will however, try to explain what those 37.5 million transistors under the hood are up to.

The Athlon XP 2100+ Exposed
What's going on in there!?!

We used H-Oda's popular WCPUID to see what it can tell us about the inner workings of AMD's new flagship processor.  As most of you already know, the 2100+ moniker is not used to denote actual clock speed but rather the processor's relative performance rating, when compared to other x86 CPUs in its class.

CPU and Cache ID


As you can see, the AMD Athlon 2100+ is running at an actual clock speed of 1733MHz (1737MHz. in our screenshot due to the slightly more aggressive timings of our nForce powered reference board).  This clock speed is attained using a multiplier of 13 and a front side bus of 133Mhz. (13x133=1733).  We also took a snapshot of the CacheID information.  Athlon XPs are equipped with 64K of 2-Way set associative Instruction L1 cache, 64K of 2-Way set associative data L1 cache and 256K of full speed, 16-Way set associative L2 cache, for a grand total of 384K of effective on chip cache.  Up until recently, the Athlon XPs held a slight edge in this area over the original Pentium 4 Willamette core with 256K.  However, with the release of the "Northwood" P4, Intel has increased their cache size to 512K.

We'd should also quickly mention that The Athlon XP 2100+ requires the same 1.75 volts to operate as other Athlon XP CPUs, and needs a cooler that can dissipate a similar amount of heat to the 2000+.  Throughout our testing we used a ThermalRight SK-6 with a 38CFM fan and core temperatures never went past 44C at full load.

Overclocking The 2100+
An AMD .18 core at 2GHz.?  Perhaps (We'll have to tell ya later!)

Unfortunately, we've only had our CPU for a few days and were not able to sufficiently unlock and properly test the overclocking potential of our particular Athlon XP 2100+.  However, even without a run of overclocked benchmark scores, there is still some interesting information we can cover with regards to overclocking...

If you're an avid reader of sites like HotHardware, you have undoubtedly heard of the procedures to unlock Athlon processors by connecting the L1 bridges on the top of the CPU.  Back in the early "Thunderbird" days, a number 2 pencil was all that was needed to connect these bridges and unlock your CPU's multiplier.  Since then, things have hanged slightly with the "Palomino" based Athlon XPs.  Users are still required to connects the L1 bridges to unlock their CPU but now there are deep (relatively speaking) valleys that need to be filled with non-electrically conductive material before you can connect the bridges.  Some users, however, have found that their new CPUs also had burned traces on their L1 bridges, making them impossible to connect.  Rumors started circulating that AMD had started "hard locking" their CPUs, much to the dismay of the enthusiast community.  Take a look at these close-ups.

The Bad...                               The Good...

The picture on the left is a close-up of an Athlon XP 2000+ we recently acquired, and the picture on the right is a close-up of the Athlon XP 2100+ we tested in this article.  Notice that the traces on the 2000+ are almost completely burned, making this CPU impossible to unlock.  The 2100+ on the other hand is cut very cleanly.  Also worth mentioning is that the CPU on the left was an AGOGA stepping, while the 2100+ CPU on the right was a newer AGOIA stepping, so we can deduce that burning the traces is not something AMD is doing with all of their newer CPUs.  Some other hardware sites had mentioned that they received official work from AMD, that they have NOT changed their stance on locking their CPUs.  If you ask us, we would theorize that quite possibly the machinery used to cut the traces was simply out of alignment when a large batch of CPUs passed through it.  We're just speculating here however.  So, unless AMD comes forth tomorrow and says they will be hard locking all of their future CPUs, we can all let out a collective sigh of relief.

On to the Benchmarks!