First Tests: AMD's Dual-Core Chip Delivers Real Power Boost

AMD fans need wait no longer for dual-core desktop processors--they're ready now. And in our exclusive tests of an AMD reference system, we found that it beat Intel's dual-core Pentium Extreme Edition across the board.

As with dual-core Pentium EE systems, you'll get the most performance benefit when you're working with multiple applications at once, or when you use multithreaded software, which can recognize more than one processor.

Dual-core chips build in two processing cores, in effect giving you two CPUs in one piece of silicon. You also get two L2 memory caches, one for each core--the 2.4-GHz Athlon 64 X2 4800+ chip we tested, for example, had 1MB of L2 per core (CPUs also have 64KB of L1 cache per core). The Athlon 64 X2 processors (formerly code-named Toledo) all have 64-bit support and will ship in June, joining AMD's already-available dual-core Opteron server and workstation processors. Additional X2 models range from the 2.4-GHz 4600+ with 512KB of L2 cache per core to the 2.2-GHz 4200+ with 512KB of L2 cache per core.

You may be able to upgrade your existing Athlon 64 PC to the new chips with a BIOS change--no need to buy a new board. Check AMD's site for specifics on motherboard support.

Speed Boost

We tested a reference system running Windows XP Professional that AMD provided. It came with 1 gigabyte of 400-MHz DDR memory, a 10,000-rpm 74GB hard disk, and an NVidia GeForce 6800 Ultra graphics card with 256MB of DDR3 RAM.

Though it was not the top-scoring system we've ever tested, it earned second place with a 116 mark on PC WorldBench 5, and handily beat the 95 score of the 3.2-GHz Pentium Extreme Edition 840 dual-core Intel reference system we tested previously. It also bested the average score of 107 of two previously tested 2.6-GHz Athlon 64 FX-55 systems, which use AMD's current fastest single-core CPU, as well as the 102 score of the Intel reference PC using the 3.73-GHz, 64-bit Pentium EE chip, a single-core CPU.

The AMD unit truly showed its prowess on the multitasking portion of WorldBench 5, where its 6-minute, 44-second time was 3 minutes, 42 seconds faster than the Athlon 64 FX-55 systems' average and about 3 minutes faster than the dual-core P4 reference PC. It also performed well with multithreaded applications such as Windows Media Encoder and Roxio VideoWave. With the former, it shaved about 90 seconds from the roughly 5.5-minute and 6-minute times of the dual-core P4 and two Athlon 64 FX-55 PCs, respectively. With VideoWave, its 4-minute time shaved about 30 seconds from the dual core Intel PC, and about 50 seconds from the average of the two Athlon 64 FX-55 machines.

Though games have yet to be optimized for dual-core--that's coming at the end of the year--we saw no real performance degradation with the new chip. Generally, dual-core machines will earn their keep by allowing you to actually work while, say, a virus check goes on in the background, or while you use your PC to record TV and surf the Web.

Kevin Krewell, editor-in-chief of Microprocessor Report, says he'd recommend them for Media Center PCs in particular. They not only let you multitask, but many of the media encoders are multithreaded and can take advantage of dual-core technology.

If you want one of these powerful systems, you will be paying for it: 4800+ chips alone will cost $1001 each in quantities of 1000, while Intel's 3.2-GHz Pentium EE 840s sell for $995 each in the same quantities. The entry-level Athlon X2 chips will be about half that much, however, so you can still get the benefits of 64-bit technology and dual-core processing without breaking the bank.

Intel devotees should also be seeing Pentium D-based systems available this month, which should also be considerably cheaper than those with the Pentium EE 840.

Tech Battle

AMD has made claims that its dual-core processors were built from the ground up for the technology, while Intel's were rushed to market. In this particular case, Krewell tends to side with AMD. He says it was clear from early presentations of its Opteron chips (ones code-named Hammer in particular) that hooks were in there for a second processor core.

On the other hand, Intel, Krewell says, was going down a single-core path, constantly revving the speed to get more and more performance, but realized it was not the best solution and backtracked. Though there are indications that Intel had plans for dual-core chips prior to the Pentium EE announcements, "you can tell from looking at the [current] processor die photos that these are two separate CPUs minimally connected," he explains.

The next Itanium and the first dual-core mobile Pentium chip, however, look to be dual-core designs from the ground up, he says.

AMD has one other advantage over Intel's dual-core chips: heat. Its X2s hover around 100 watts, while the Pentium EE is at about 130 watts.

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