by John Reynolds
With the launch of the Athlon 64 X2 dual-core processors earlier this year, AMD successfully leveraged the advantages of their traditional single-core parts into this new product line. While X2 availability trailed behind that of Intel’s dual-core offerings, AMD’s lead in 3D gaming applications was carried over from the Athlon 64 family, allowing the smaller company to claim comprehensive performance dominance over virtually all market segments. Yet the X2 lineup’s pricing left Intel in a good position to grab a sizable portion of dual-core market share with the company’s relatively inexpensive Pentium D dual core parts, and AMD obviously seeks to address this situation with the introduction of the X2 3800+.
Like the earlier Athlon X2s, the 3800+ is manufactured using AMD’s 90nm SOI (Silicon on Insulator) processor at the company’s Dresden plant in Germany. The 3800+ is clocked at an even 2.0GHz, compared to the 2.2GHz and 2.4GHz clock speeds of the initial X2 lineup. Each core of the new processor has 128K of L1 cache (64K for instruction and data apiece) and 512K per core of L2 cache, similar to the 4200+ and 4600+ in terms of cache sizes. Perhaps the most interesting specification for the 3800+, however, is that the part’s maximum wattage is 89W, considerably lower than that of the faster X2s, which consume upwards of 110W, and substantially lower than Intel’s dual cores. In addition, as mentioned in SimHQ’s initial look at AMD’s X2 processors, the Athlon 64 architecture greatly benefits from an on-die memory controller that, using a 128-bit crossbar switch, works with the SRQ (System Request Queue) of the X2s to facilitate the arbitration of execution requests to the two cores. In contrast, Intel’s dual core parts have to send execution requests across the system bus to the north bridge chip, where Intel’s memory controller is located. The X2 processors are also compatible with most existing 939-pin motherboards, though this will change next year according to AMD’s roadmap, which shows the company moving to a 940-pin socket and DDR2 support sometime in the first half of 2006.
The X2 3800+’s pricing is $354 in 1,000-unit quantities, so initial sales should remain under $400 USD. This review will test the 3800+ against the Pentium D 820, a 2.8GHz dual core from Intel currently selling for slightly under $250; we’ll also include scores from high-end dual cores such as AMD’s X2 4800+ and the Pentium 4 840 Extreme Edition, with AMD’s FX-55, the fastest single-core CPU available to SimHQ at this time, likewise included.
Test Systems Setup
- ASUS A8N SLI Deluxe (nForce4 chipset) motherboard
- 1 GB (2×512 MB) Corsair DDR400 memory (2-2-2-5)
- Athlon 64 FX-55 (2.6GHz single core)
- Athlon 64 X2 4800+ (2.4GHz dual core)
- Athlon 64 X2 3800+ (2.0GHz dual core)
- Intel 955XBK (955X chipset) motherboard
- 1 GB (2×512 MB) Micron DDR2 533MHz memory (4-4-4-12)
- Pentium 4 840 Extreme Edition (3.2GHz dual core)
- Pentium D Model 820 (2.8GHz dual core)
A Radeon X800 XT graphics board was installed in both test systems and used the Catalyst 5.7 driver build. Identical hard and optical drives were also used in both systems, and both motherboards were running with the latest BIOS and chipset drivers installed. As standard practice, 32-bit color and trilinear texture filtering were the default baseline during testing, and anti-aliasing and anisotropic texture filtering were disabled throughout all tests. Also, Windows XP Professional was configured to have Automatic Update, System Restore, and all unnecessary startup services disabled. Last, the licensed version of Fraps 2.6.3 was used to record performance scores unless otherwise noted.