Technical Specifications Compared

AMD Athlon 64 X2 4800+ Technical Specifications Compared With Intel Dual-Core Processors
Processor NameAMD Athlon 64 X2Pentium DPentium Extreme EditionProcessor ModelProcessor FrequencyNo. of CoresHyper-Threading TechnologyNo. of Logical ProcessorsFront Side Bus (MHz)HyperTransport BusL1 Cache (data + instruction)L2 CacheL3 CacheVID (V)Icc (max) (A)TDP (W)Execute Disable BitIntel EM64T / AMD64Enhanced Intel SpeedStep Technology (EIST) / AMD Cool 'n' QuietPackagingProcess TechnologyProcessor CodenameDie SizeNo. of Transistors

4800+	840	840
2.4GHz	3.2GHz	3.2GHz
2	2	2
-	No	Yes
2	2	4
-	800	800
1GHz (2000MT/s)	-	-
(64KB + 64KB) x 2	(16KB + 12KB) x 2	(16KB + 12KB) x 2
1MB x 2	1MB x 2	1MB x 2
-	-	-
1.35 - 1.40	1.20 -1.40	1.20 -1.40
80	125	125
110	130	130
Yes	Yes	Yes
Yes	Yes	Yes
Yes	Yes	No
Socket-939	LGA775	LGA775
90nm SOI	90nm	90nm
Toledo	Smithfield	Smithfield
199mm²	206mm²	206mm²
233 million	230 million	230 million

As you can see in the table above, the fastest available Athlon 64 X2 processor is rated at 4800+ and it's clocked at only 2.4GHz, as compared to Intel's high-end 3.2GHz dual-core processors with model number 840. The specifications of these processors are quite alike, with features like 64-bit addressing, Execute Disable Bit and large 1MB Level 2 caches on each core. However, the biggest difference lies in the I/O throughput, where AMD's part retains its HyperTransport bus at 1GHz while Intel took a step back with a slower 800MHz bus. As discussed before, the slower bus on Intel's dual-core processor is a major setback as both cores have to share the narrow bus. However, as we know it, AMD's 1GHz HyperTransport bus is purely meant for I/O purposes and its memory directly accessed by the cores. In terms of overall throughput, it's easy to see that AMD still has the upper hand.

Though operating at a much lower clock speed, the Athlon 64 X2 still required quite a bit of power to run. At a maximum thermal design power (TDP) of 110W, it's only 20W lower than Intel's dual-core processors. We expected a much lower TDP value since the Athlon 64 X2 is, after all, built on state-of-the-art 90nm SOI process technology. The operating voltage of the processor is a tad higher and it's likely the reason for its TDP value.

Comparing the size of the die, AMD's dual-core part is a little smaller than Intel's although it housed about 3 million more transistors. It's quite commendable since AMD's processor has more than just the two processor cores - we have to take into account the HyperTransport link and dual-channel memory controller as well. In the end, it's a lot of real estate savings in terms of silicon usage since you can literally take the northbridge out of a system board design. Unfortunately, not many chipset manufacturers offer such designs, except for NVIDIA's nForce4 and ULi's M1689 which are both single chip solutions.

Since the memory controller is built into the processor, the major drawback for AMD's Athlon 64 X2 right now is its support for current memory standards. As we all know it, prices of DDR2 memory modules have reached a very comfortable level today and we have arrived at an inflection point where prices of DDR2 memory are beginning to cost less than DDR1. If this carries on, it will soon be too costly to build AMD-based systems since they only support the older DDR standard. Think of it this way, is it worth to invest in an old memory technology? We can already hear skeptics chanting away that DDR2 operates at much higher latencies, but that's not quite true any longer. Lower latency DDR2 memory is fast replacing the initial high latency ones and as mentioned, the prices are coming down. Although AMD has plans to roll out new processors supporting DDR2, it is not without a price. Firstly, current motherboard manufacturers have to redesign their boards for DDR2 memory, including introducing a new socket (dubbed M2) to support these new DDR2 processors. Secondly, AMD actually planned to introduce these new processors only in the second half of 2006 - which, in our opinion, is way too late. If you purchase an Athlon 64 X2 today, a year later, your memory modules, processor and motherboard will go obsolete once the new Socket M2 hits the market.

Test Setup & Benchmarks

In this review, we'll be comparing results from the Athlon 64 X2 processor with dual-core performance results from Intel. We kept the system setup similar in both testbeds so as to minimize any performance variation arising from the use of different hardware components.


The components used in the AMD Athlon 64 X2 tesbed include :-